Battery manufacturing method and battery manufacturing system

Abstract

Increase productivity. [Solution] The method for manufacturing a battery includes the steps of: arranging two power generation elements with their end faces facing each other and within a first distance (S12); applying a coating liquid to the adjacent portion of the end faces (S14); and forming a coating film on each end face of the two power generation elements by separating the end faces from each other by a second distance or more, which is longer than the first distance, after applying the coating liquid (S16).

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a battery and a battery manufacturing system.

Background Art

[0002] Patent Document 1 discloses adsorbing after cutting a battery element.

[0003] Patent Document 2 discloses cutting after adsorbing a battery base material.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] [[ID=4,3]]In the prior art, further improvement in battery productivity is desired. In particular, in order to enhance the reliability of a power generation element, a process of forming a coating film on an end face of the power generation element is performed, but this process generally requires a large number of man-hours. Therefore, the production efficiency of the end face treatment process is an important point in practical manufacturing characteristics.

[0006] Therefore, the present disclosure provides a method for manufacturing a battery and a battery manufacturing system that can enhance productivity.

Means for Solving the Problems

[0007] A method for manufacturing a battery according to one aspect of the present disclosure includes the steps of: arranging two power generation elements with their end faces facing each other and within a first distance of each other; applying a coating liquid to the portions of the end faces that are close together; and forming a coating film on each end face of the two power generation elements by separating the end faces from each other by a second distance or more that is longer than the first distance after applying the coating liquid.

[0008] A battery manufacturing system according to one aspect of the present disclosure comprises two holding units that hold two power generation elements and whose relative positions can be changed; a coating apparatus that forms a coating film on each of the end faces of the two power generation elements; and a control unit that controls the two holding units to change the relative positions of the two power generation elements, wherein the two holding units are arranged so that the end faces of the two power generation elements face each other and are in close proximity within a first distance, the coating apparatus applies a coating liquid to the close proximity of the end faces, and after the coating liquid has been applied, the two holding units move the end faces apart to a second distance or more, which is longer than the first distance. [Effects of the Invention]

[0009] This disclosure provides a battery manufacturing method and a battery manufacturing system that can increase productivity. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a flowchart showing an example of a battery manufacturing method according to Embodiment 1. [Figure 2] Figure 2 is a schematic diagram showing a first example of a battery manufacturing method according to Embodiment 1. [Figure 3] Figure 3 is a schematic diagram showing the curing process of the battery manufacturing method according to Embodiment 1. [Figure 4] Figure 4 is a schematic diagram showing a second example of the battery manufacturing method according to Embodiment 1. [Figure 5] Figure 5 is a schematic diagram showing a third example of the battery manufacturing method according to Embodiment 1. [Figure 6]FIG. 6 is a plan view of a flat plate including a plurality of power generation elements according to Embodiment 2. [Figure 7] FIG. 7 is a cross-sectional view of a flat plate including a plurality of power generation elements according to Embodiment 2. [Figure 8] FIG. 8 is a schematic view showing the top surface, side surface, and front surface of a first example of a holding unit according to Embodiment 2. [Figure 9] FIG. 9 is a schematic view showing the top surface, side surface, and front surface of a second example of a holding unit according to Embodiment 2. [Figure 10] FIG. 10 is a schematic view showing the top surface, side surface, and front surface of a third example of a holding unit according to Embodiment 2. [Figure 11] FIG. 11 is a flowchart showing an example of a method for manufacturing a battery according to Embodiment 2. [Figure 12] FIG. 12 is a block diagram showing the configuration of a battery manufacturing system according to Embodiment 2. [Figure 13] FIG. 13 is a schematic view showing a fixing step of a method for manufacturing a battery according to Embodiment 2. [Figure 14] FIG. 14 is a schematic view showing a cutting step of a method for manufacturing a battery according to Embodiment 2. [Figure 15] FIG. 15 is a schematic view showing a holding step of a method for manufacturing a battery according to Embodiment 2. [Figure 16] FIG. 16 is a schematic view showing a coating step of a method for manufacturing a battery according to Embodiment 2. [Figure 17] FIG. 17 is a schematic view showing a coating step of a method for manufacturing a battery according to Embodiment 2. [Figure 18] FIG. 18 is a schematic view showing a first example of a step for changing the positional relationship between power generation elements in a method for manufacturing a battery according to Embodiment 2. [Figure 19] FIG. 19 is a schematic view showing a second example of a step for changing the positional relationship between power generation elements in a method for manufacturing a battery according to Embodiment 2. [Figure 20] FIG. 20 is a schematic view showing a third example of a step for changing the positional relationship between power generation elements in a method for manufacturing a battery according to Embodiment 2. [Figure 21A] FIG. 21A is a cross-sectional view showing an example of a schematic configuration of a unit cell included in a power generation element according to each embodiment. [Figure 21B] FIG. 21B is a cross-sectional view showing an example of a schematic configuration of a unit cell included in a power generation element according to each embodiment. [Figure 21C] FIG. 21C is a cross-sectional view showing an example of a schematic configuration of a unit cell included in a power generation element according to each embodiment.

Embodiments for Carrying Out the Invention

[0011] (Summary of the Present Disclosure) A method for manufacturing a battery according to a first aspect of the present disclosure includes a step of arranging end faces of two power generation elements to face each other and be close to each other within a first distance, a step of applying a coating liquid to a proximity portion between the end faces, and a step of forming a coating film on each end face of the two power generation elements by separating the end faces from each other by a second distance longer than the first distance after applying the coating liquid.

[0012] Thereby, a battery can be manufactured with high productivity. Specifically, when the end faces of a plurality of power generation elements face each other and are close to each other, and a coating liquid is applied to the proximity portion between the end faces, for example, the coating liquid spreads into the gap between the end faces of the power generation elements due to capillary action. Therefore, coating can be performed on two end faces simultaneously by one operation of the coating process. Since the number of coating operations can be reduced compared to the case where each end face of a plurality of power generation elements is coated one by one, productivity can be increased.

[0013] A method for manufacturing a battery according to a second aspect of the present disclosure includes, in the method for manufacturing a battery according to the first aspect, a step of bringing the end faces closer to each other after applying the coating liquid and before separating the end faces from each other by the second distance or more.

[0014] Thereby, it is possible to promote the spread of the coating liquid over the entire end faces of adjacent power generation elements, so that the coating time can be shortened.

[0015] Furthermore, the battery manufacturing method according to the third aspect of this disclosure includes, in the battery manufacturing method according to the second aspect, a step of separating the end faces by a distance less than the second distance after applying the coating liquid and before bringing the end faces together.

[0016] This further promotes the spread of the coating liquid across the entire end faces of adjacent power generation elements, thereby enabling a further reduction in coating time.

[0017] Furthermore, a battery manufacturing method according to a fourth aspect of the present disclosure includes a step of sliding the end faces together after applying the coating liquid and before separating the end faces by a distance greater than or equal to the second distance, in a battery manufacturing method according to any one of the first to third aspects.

[0018] This allows the end faces of adjacent power generation elements to be rubbed together via the coating liquid after application, further promoting the spread of the coating liquid and shortening the coating time even further.

[0019] Furthermore, in the battery manufacturing method according to the fifth aspect of this disclosure, the direction in which the end faces slide against each other is parallel to the main surface of the power generation element, in the battery manufacturing method according to the fourth aspect.

[0020] This allows for the promotion of coating fluid spread while suppressing peeling or deformation of the power generation elements. This enables both improved productivity through reduced coating time and improved yield and reliability by suppressing damage to the power generation elements.

[0021] Furthermore, in the battery manufacturing method according to the sixth aspect of this disclosure, in the battery manufacturing method according to any one of the first to fifth aspects, the direction in which the coating liquid is applied in the application step is within the range of -45° to +45°, centered on the direction perpendicular to the main surface of the power generation element.

[0022] This allows for easier inspection of the areas where end faces meet by, for example, applying the coating solution at an angle, from a direction perpendicular to the main surface of the power generation element. For instance, a camera can be used to monitor the degree to which the coating solution fills the gaps between end faces, thus improving coating accuracy. This allows for the manufacture of highly reliable batteries.

[0023] Furthermore, a battery manufacturing method according to the seventh aspect of this disclosure is a battery manufacturing method according to any one of the first to sixth aspects, comprising the steps of: fixing each of a plurality of power generation elements contained in a flat plate; separating the plurality of power generation elements individually by cutting the flat plate; and a plurality of holding units whose relative positions can be changed holding the plurality of power generation elements, wherein the two power generation elements are two of the plurality of power generation elements held by the plurality of holding units, and the arrangement step and the formation step are performed by the two holding units that hold the two power generation elements.

[0024] This allows the plate to be cut while the multiple power generation elements contained within it are fixed, and by separating the multiple power generation elements individually, the dissipation of the power generation elements after cutting can be suppressed. Furthermore, it can suppress damage to the cut surface caused by individual power generation elements colliding with each other during cutting, thereby preventing short circuits among the power generation elements.

[0025] Furthermore, by having multiple holding units whose relative positions can be changed, each of the multiple power generation elements can be held, making it easy to control the relative positions between the power generation elements. This further increases productivity. Thus, the battery manufacturing method according to this embodiment can improve productivity and yield.

[0026] Furthermore, in the battery manufacturing method according to the eighth aspect of this disclosure, in the battery manufacturing method according to the seventh aspect, the fixing step is performed by a jig different from the plurality of holding units, and the holding step is performed by the plurality of holding units while the jig is fixing each of the plurality of power generation elements.

[0027] This allows for the use of mechanical clamping, such as a jig, to securely fix multiple power generation elements, thereby ensuring stable mounting of the flat plate. Furthermore, since each power generation element is held in place by multiple holding units while fixed to the jig, the possibility of dissipation and damage to the power generation elements is further reduced. As a result, productivity and yield can be further improved.

[0028] Furthermore, in the battery manufacturing method according to the ninth aspect of this disclosure, the fixing step is performed by the plurality of holding units, in the battery manufacturing method according to the seventh aspect.

[0029] This allows fixing and holding to be performed with the same holding unit, further reducing the possibility of power generation element dissipation and damage. As a result, productivity and yield can be further improved.

[0030] Furthermore, in the battery manufacturing method according to the tenth aspect of this disclosure, in the battery manufacturing method according to any one of the seventh to ninth aspects, the holding step is performed by pressing down, sandwiching, or adsorbing each of the plurality of power generation elements.

[0031] This allows the power generation element to be mechanically and firmly fixed by pressing or clamping, enabling stable cutting or coating. Therefore, productivity and yield can be further improved. Furthermore, for example, power generation elements that were previously fixed by mechanical pressing can now be held by suction from the back, allowing for smooth transfer of power generation elements from the jig to the holding unit. This, in turn, can further improve productivity.

[0032] Furthermore, in the battery manufacturing method according to the 11th aspect of this disclosure, in the battery manufacturing method according to any one of the 7th to 10th aspects, the plurality of holding units can change at least one of the planar position, height, and rotation angle of the power generation element they hold.

[0033] This makes it easy to change the relative positions of the power generation elements to an appropriate state according to the content of the next process.

[0034] Furthermore, in the battery manufacturing method according to the twelfth aspect of this disclosure, in the battery manufacturing method according to any one of the seventh to eleventh aspects, the plurality of holding units change at least one of the planar position, height, and rotation angle of the power generation element being held during the period in which the coating liquid is applied.

[0035] This means that, for example, if coating is required on the end faces of all four sides of multiple rectangular flat power generation elements, By rotating multiple power generation elements held in a holding unit during the process, coating can be applied to all four sides. Furthermore, to avoid collisions between power generation elements during rotation, the planar distance between them can be increased or their heights staggered before rotation. This further improves productivity and yield.

[0036] Furthermore, in the battery manufacturing method according to the 13th aspect of this disclosure, in the battery manufacturing method according to any one of the 7th to 12th aspects, the plurality of holding units change at least one of the planar position, height, and rotation angle of the power generation element they hold based on numerical information output from the control unit.

[0037] This allows for improved precision in controlling the relative positions of each of the multiple holding units.

[0038] Furthermore, the battery manufacturing method according to the 14th aspect of this disclosure is a battery manufacturing method according to any one of the 1st to 13th aspects, wherein the power generation element includes a positive electrode plate, a negative electrode plate, and an intermediate layer located between the positive electrode plate and the negative electrode plate.

[0039] This makes it possible to easily apply coating to, for example, a single unit cell or a laminated structure of multiple unit cells.

[0040] Furthermore, the battery manufacturing method according to the 15th aspect of this disclosure is a battery manufacturing method according to any one of the 1st to 14th aspects, wherein the power generation element is a power generation element for an all-solid-state battery.

[0041] This eliminates the risk of electrolyte leakage during the manufacturing process for power generation elements in all-solid-state batteries, and facilitates processing of the end faces of the power generation elements. Therefore, it is suitable for manufacturing methods in which the power generation elements are held in a holding unit with a changeable positional relationship for cutting and end face processing. This is extremely advantageous for improving productivity and yield.

[0042] Furthermore, a battery manufacturing system according to the 16th aspect of the present disclosure comprises two holding units that can change the relative positions of each other and hold two power generation elements, a coating apparatus that forms a coating film on each end face of the two power generation elements, and a control unit that changes the relative positions of the two power generation elements by controlling the two holding units, wherein the two holding units are arranged so that the end faces of the two power generation elements face each other and are in close proximity within a first distance, the coating apparatus applies a coating liquid to the close proximity of the end faces, and after the coating liquid has been applied, the two holding units move the end faces apart to a second distance or more, which is longer than the first distance.

[0043] This allows for the production of batteries with high productivity, similar to the battery manufacturing method described above.

[0044] Furthermore, in the battery manufacturing system according to the 17th aspect of this disclosure, the direction in which the coating device applies the coating liquid is inclined with respect to a direction perpendicular to the main surface of the power generation element, as is the case in the battery manufacturing system according to the 16th aspect.

[0045] This allows for easier inspection of the areas where end faces meet by applying the coating solution at an angle, from a direction perpendicular to the main surface of the power generation element. For example, by using a camera to check how well the coating solution is filling the gaps between the end faces, coating accuracy can be improved. As a result, highly reliable batteries can be manufactured.

[0046] Furthermore, the battery manufacturing system relating to the 18th aspect of this disclosure is the 16th or 17th aspect. In the battery manufacturing system relating to the above, the end faces are connected by the coating liquid after the coating liquid is applied and before they are separated by a distance greater than the second distance.

[0047] This makes it easier for the coating solution to evenly cover each of the two adjacent end faces. The improved coating accuracy allows for the manufacture of highly reliable batteries.

[0048] Furthermore, a battery manufacturing system according to the 19th aspect of this disclosure is a battery manufacturing system according to any one of the 16th to 18th aspects, comprising: a cutting device for individually separating a plurality of power generation elements by cutting a flat plate while each of the plurality of power generation elements contained in the flat plate is fixed; and a plurality of holding units for holding the plurality of power generation elements, the relative positions of which can be changed, wherein the two holding units are two of the plurality of holding units.

[0049] This method allows for the cutting of a flat plate while the multiple power generation elements contained within it are fixed in place, thereby separating the elements individually and suppressing their dissipation after cutting. Furthermore, it reduces damage to the cut surface caused by individual power generation elements colliding with each other during cutting, thus preventing short circuits among the power generation elements.

[0050] Furthermore, multiple holding units, whose relative positions can be changed, hold each of the multiple power generation elements, allowing for easy control of the relative positions between the power generation elements. This further enhances productivity. Thus, the battery manufacturing system according to this embodiment can improve productivity and yield.

[0051] Embodiments of the present disclosure will be described below with reference to the drawings.

[0052] The embodiments described below are all general or specific examples. The numerical values, shapes, materials, components, arrangement and connection configurations of components, steps, and the order of steps shown in the following embodiments are examples only and are not intended to limit this disclosure. Furthermore, any components in the following embodiments that are not described in an independent claim will be described as optional components.

[0053] Furthermore, each figure is a schematic diagram and not necessarily a strictly accurate representation. Therefore, for example, the scale may not necessarily match in each figure. Also, in each figure, substantially identical components are given the same reference numerals, and redundant explanations are omitted or simplified.

[0054] Furthermore, in this specification, terms indicating relationships between elements such as parallelism, terms indicating the shape of elements such as rectangles, and numerical ranges do not represent only strict meanings, but also include substantially equivalent ranges, such as differences of a few percent.

[0055] Furthermore, in this specification, the terms "upper" and "lower" do not refer to the upward (vertically upward) and downward (vertically downward) directions in absolute spatial perception, but rather are used as terms defined by the relative positional relationship based on the stacking order in a stacked configuration. In addition, the terms "upper" and "lower" apply not only when two components are spaced apart and another component exists between them, but also when two components are placed in close contact with each other and touching. In this specification, for the sake of clarity, for two power generation elements, the side on which the coating device is located, i.e., the side to which the coating liquid is first applied, is described as the "upper side" or "upper," and the opposite side is described as the "lower side" or "lower."

[0056] Furthermore, in this specification, ordinal numbers such as "first," "second," etc., refer to the first, second, etc., unless otherwise specified. This does not refer to the number or order of components, but is used to avoid confusion and distinguish similar components.

[0057] (Embodiment 1) [Battery manufacturing method] First, the manufacturing method of the battery according to Embodiment 1 will be explained using Figures 1 to 3.

[0058] Figure 1 is a flowchart showing an example of a battery manufacturing method according to this embodiment. Figure 2 is a schematic diagram showing a first example of a battery manufacturing method according to this embodiment. Note that Figure 2 shows a side view of the flat power generation elements 20A and 20B as seen from the side. Figure 3 is a schematic diagram showing an example of a curing process in the battery manufacturing method according to this embodiment. Specifically, Figure 3(a) shows a top view of the flat power generation elements 20A and 20B as seen from above. Figure 3(b) shows a side view of the flat power generation elements 20A and 20B as seen from above, similar to Figure 2.

[0059] As shown in Figure 1, first, two power generation elements are prepared (S10, preparation step).

[0060] Next, the end faces of the two power generation elements are placed facing each other and in close proximity (S12, proximity placement step). For example, as shown in Figure 2(a), the end face 21A of power generation element 20A and the end face 21B of power generation element 20B are placed facing each other and in close proximity. At this time, the distance D between end face 21A and end face 21B is within the first distance D1.

[0061] The first distance D1 is, for example, the maximum coating width of the coating liquid 30. The first distance D1 may also be the nozzle diameter of the coating device 700 that dispenses the coating liquid 30. For example, the first distance D1 is 2 mm or less, but may also be 1 mm or less. Also, for example, the first distance D1 is 0.05 mm or more, but may also be 0.1 mm or more. Note that the upper and lower limits of the first distance D1 are not limited to these.

[0062] Furthermore, when end faces 21A and 21B are in close proximity, they are not in close contact, that is, they are not in complete contact. In other words, "close proximity" means that while parts of end faces 21A and 21B may be in contact, there is at least a gap 22 large enough for the coating liquid 30 to penetrate. For example, end faces 21A and 21B are not in contact at all, and the distance D is greater than 0. As will be described in more detail later, when the distance D is changed as shown in Figure 4, end faces 21A and 21B may be in close contact at the timing when the coating liquid 30 is applied from the coating device 700 (Figure 4(a)).

[0063] Next, as shown in Figure 1, the coating liquid is applied to the adjacent portion of the opposing end faces (S14, application step). For example, as shown in Figure 2(a), the coating liquid 30 is applied from the coating apparatus 700 towards the gap 22 between the two power generation elements 20A and 20B. The coating apparatus 700 is, for example, an inkjet coating apparatus, a dispenser coating apparatus, or a screen coating apparatus, but is not limited to these coating apparatuses.

[0064] The gap 22 is the space in the area where end faces 21A and end face 21B face each other. The vicinity of end faces 21A and 21B is the portion that includes end faces 21A and 21B and the gap 22 in a plan view. Here, "plan view" refers to the direction perpendicular to the main surface of the flat power generation element 20A.

[0065] The coating liquid 30 is formed using, for example, an insulating material. Specifically, the coating liquid 30 includes an insulating resin. The insulating resin is, for example, an epoxy resin, but is not limited to this. Usable insulating materials are selected based on various properties such as flexibility, gas barrier properties, impact resistance, and heat resistance.

[0066] Here, the direction in which the coating liquid 30 is applied is inclined obliquely with respect to the direction perpendicular to the main surface of the power generation element 20A. The direction in which the coating liquid 30 is applied is within the range of -45 degrees to +45 degrees, centered on the direction perpendicular to the main surface of the power generation element 20A. That is, the angle θ that the direction in which the coating liquid 30 is applied makes with respect to the direction perpendicular to the main surface of the power generation element 20A is, for example, within the range of -45 degrees to +45 degrees.

[0067] By tilting the direction in which the coating liquid 30 is applied from a direction perpendicular to the main surface of the power generation element 20A, the design flexibility of the equipment can be increased. For example, by tilting the direction in which the coating liquid 30 is applied, it becomes easier to fine-tune and control the coating conditions while monitoring the application state of the coating liquid 30 from above with a camera. The angle θ may be within the range of -15 degrees to +15 degrees. This makes it possible to improve the accuracy of the application position of the coating liquid 30 and to miniaturize the equipment.

[0068] Furthermore, the direction in which the coating liquid 30 is applied may be perpendicular to the main surface of the power generation element 20A. In this case, the coating liquid 30 can be applied to the gap 22 from directly above, thereby improving the accuracy of the application position.

[0069] As shown in Figure 2(b), the coating liquid 30 applied from the coating device 700 penetrates into the gap 22 between the end face 21A of the power generation element 20A and the end face 21B of the power generation element 20B. In other words, the end faces 21A and 21B become connected by the coating liquid 30. For example, if the power generation elements 20A and 20B are positioned so that the penetration direction, i.e., the downward direction in the figure, is vertically downward, the coating liquid 30 will penetrate into the gap 22 using its own weight. Furthermore, capillary action occurs, allowing the coating liquid 30 to penetrate evenly along the end faces 21A and 21B. Note that if capillary action can be utilized, the direction of penetration of the coating liquid 30 does not have to be vertically downward. As a result, as shown in Figure 2(c), the coating liquid 30 spreads over the entire surface of the end faces 21A and 21B. The coating liquid 30 can be applied evenly to both sides of the end faces 21A and 21B.

[0070] After applying the coating liquid 30, the end faces are separated (S16, separation step) as shown in Figure 1. Specifically, as shown in Figure 2(d), the distance D between the end face 21A of the power generation element 20A and the end face 21B of the power generation element 20B is increased to a second distance D2 or greater. As a result, the coating liquid 30 separates into the end face 21A side and the end face 21B side, and coating films 30A and 30B are formed on each end face.

[0071] The second distance D2 is longer than the first distance D1. The second distance D2 is the distance at which the coating liquid 30 applied to each of the end faces 21A and 21B can be completely separated. For example, the second distance D2 is 2 mm or more. Also, for example, the second distance D2 is 0.05 mm or less. However, the upper and lower limits of the second distance D2 are not limited to these.

[0072] Next, as shown in Figure 1, the coating film is dried and / or cured (S18, curing step). For example, thermal curing and / or ultraviolet curing can be used as curing methods. For example, as shown in Figure 3, the coating films 30A and 30B can be cured by the curing device 900 with the distance between the respective end faces 21A and 21B of the power generation elements 20A and 20B widened. This allows the coating films 30A and 30B to be stabilized efficiently.

[0073] The curing device 900 is, for example, an ultraviolet lamp that emits ultraviolet light, but is not limited to this. The curing device 900 may be a heating device that applies heat to the coating films 30A and 30B. The curing device 900 may include both an ultraviolet lamp and a heating device. The curing device 900 is selected based on the curing properties of the coating films 30A and 30B.

[0074] As described above, by arranging the end faces 21A of the two power generation elements 20A and 21B of the power generation element 20B facing each other and close together, and applying the coating liquid 30 to the close-proximity portion, it becomes possible to simultaneously form coating films 30A and 30B on the two end faces 21A and 21B. Therefore, the number of coating steps can be reduced compared to coating each end face 21A and 21B individually, thereby increasing productivity.

[0075] The relative positions of the power generation elements 20A and 20B are, for example, determined by the holding unit described in Embodiment 2, but are not limited thereto. The means for holding the power generation elements 20A and 20B and the means for changing their relative positions are not particularly limited.

[0076] Furthermore, the battery manufacturing method according to this disclosure is not limited to the method described above. For example, the example shown in Figure 2 shows that the relative positions of the two power generation elements 20A and 20B are fixed during the period in which the coating liquid 30 penetrates the gap 22, but it is not limited to this. The relative positions of the two power generation elements 20A and 20B may be changed during the period in which the coating liquid 30 penetrates. Specific examples of changing the relative positions will be described below.

[0077] [Changing the distance between end faces] First, using Figure 4, an example of changing the distance D between end faces 21A and 21B while the coating liquid 30 is penetrating the gap 22 will be explained. Figure 4 is a schematic diagram showing a second example of the battery manufacturing method according to this embodiment. Note that, similar to Figure 2, Figure 4 shows a side view of the flat power generation elements 20A and 20B as seen from the side. Figure 4(a) is the same as Figure 2(b), and shows the timing when the coating liquid 30 is applied from the coating device 700.

[0078] As shown in Figure 4(b), first, the end faces 21A and 21B are separated. For example, the distance D between the end faces 21A and 21B is made greater than the distance D at the time the coating liquid 30 was applied (Figure 4(a)). In short, the gap 22 is slightly widened. The distance D when the gap 22 is widened is in the range less than the second distance D2. That is, the end faces 21A and 21B are separated to the extent that the coating liquid 30 does not completely separate. By separating the end faces 21A and 21B and widening the gap 22, the attraction of the coating liquid 30 into the gap 22 can be promoted.

[0079] Next, as shown in Figure 4(c), the separated end faces 21A and 21B are brought closer together. For example, the distance D is made smaller than the distance D when the gap 22 is widened. In short, the gap 22 is narrowed. The distance D when the gap 22 is narrowed is within the range of the first distance D1 or less. Note that the distance D when the gap 22 is narrowed may be shorter, longer, or equal to the distance D between end faces 21A and 21B at the time the coating liquid 30 is applied (Figure 4(a)). By slightly narrowing the gap 22, it is possible to promote the thin spreading of the coating liquid 30 between the adjacent end faces 21A and 21B.

[0080] Finally, as shown in Figure 4(d), coating films 30A and 30B are formed on end faces 21A and 21B, respectively, by separating them. Figure 4(d) is the same as Figure 2(d).

[0081] The distance D can be changed in either the direction that brings the end faces closer together or the direction that moves them apart. Also, while Figure 4 shows an example where the end faces are moved apart and then brought together, the reverse is also possible. Furthermore, the process of moving the end faces apart and then closer together can be repeated multiple times. Furthermore, one of the steps of bringing the end faces closer together or moving them apart may be omitted. The specific value of distance D, the number of times to bring them closer together, the number of times to move them apart, and the execution order can be appropriately selected depending on the physical properties of the coating liquid 30 and / or the properties and shape of the end faces. In addition, in the steps of separating the end faces and bringing them closer together, both end faces 21A and 21B may be moved, or only one of them may be moved.

[0082] As described above, by applying the coating liquid 30 to the gap 22 between adjacent power generation elements 20A and 20B, and then changing the distance between their end faces, the coating liquid 30 can be distributed more quickly to each of the end faces 21A of power generation element 20A and 21B of power generation element 20B.

[0083] [Slide movement] Next, an example of sliding the end faces 21A and 21B will be explained using Figure 5. Figure 5 is a schematic diagram showing a third example of the battery manufacturing method according to this embodiment. Note that Figure 5 shows a top view of the flat power generation elements 20A and 20B as seen from the information.

[0084] Figure 5(a) is a top view of the state shown in Figure 2(b). The coating liquid 30 is applied so as to cover the end faces 21A and 21B. In this state, the adjacent end faces are slid together as shown in Figure 5(b). Specifically, the end faces 21A and 21B are slid together in a direction parallel to the main surfaces of the power generation elements 20A and 20B. By sliding in a direction parallel to the main surfaces of the power generation elements 20A and 20B, deformation and peeling of the power generation elements 20A and 20B can be suppressed. More specifically, the end faces 21A and 21B are slid together in a direction parallel to the main surfaces of the power generation elements 20A and 20B and along the end faces 21A and 21B.

[0085] For example, as shown in Figures 5(b) and 5(c), the device is slid in one direction and then in the opposite direction. This back-and-forth sliding motion may be repeated multiple times. This allows the coating liquid 30 to be applied more uniformly to each of the end faces 21A of the power generation element 20A and 21B of the power generation element 20B.

[0086] Finally, as shown in Figure 5(d), the end faces 21A and 21B are separated to form coating films 30A and 30B on each of the end faces 21A and 21B. Figure 5(d) is a top view of the state shown in Figure 2(d). In the step shown in Figure 5(d), the end faces 21A and 21B may be separated while sliding. This may promote the separation of the coating liquid 30.

[0087] Furthermore, the sliding direction may be perpendicular to the main surface of the power generation element 20A or 20B, or it may be obliquely intersecting the main surface. The amount of movement, number of times, and direction of the slide can be appropriately selected depending on the physical properties of the coating liquid 30 and / or the properties and shape of the end face. In addition, in the step of sliding the end faces together, both end faces 21A and 21B may be moved, or only one of them may be moved. Furthermore, as shown in Figure 4, the change in distance D may be combined with the sliding.

[0088] As described above, by applying the coating liquid 30 near the gap 22 between adjacent power generation elements 20A and 20B and sliding their end faces together, the coating liquid 30 can be distributed more uniformly to each of the end faces 21A of power generation element 20A and 21B of power generation element 20B.

[0089] Figures 2, 4, and 5 show examples where the end faces 21A and 21B are parallel to each other, but the examples are not limited to this. At least one of the end faces 21A and 21B may be inclined at an angle with respect to the direction perpendicular to the main surface of the power generation element 20A. In this case, the gap 22 may narrow in the direction from the bottom surface to the top surface of the power generation elements 20A and 20B. Alternatively, the gap 22 may widen in the direction from the bottom surface to the top surface of the power generation elements 20A and 20B. The cross-sectional shape of the gap 22 is not limited to a rectangle, but may be a parallelogram or a trapezoid, etc. Also, at least one of the end faces 21A and 21B may be curved in a convex or concave shape, may be stepped, or may have a convex or concave portion. In any case, the distance D can be defined as the distance on the side to which the coating liquid 30 is first applied to the end faces 21A and 21B, specifically the distance between the upper ends of each of the end faces 21A and 21B.

[0090] (Embodiment 2) Next, Embodiment 2 will be described.

[0091] Embodiment 1 showed an example in which two power generation elements are prepared individually, but Embodiment 2 differs in that it includes a step of separating the multiple power generation elements contained in the flat plate by cutting the plate. Below, we will mainly explain the differences from Embodiment 1, and the explanation of the common points will be omitted or simplified.

[0092] [Flat plate containing multiple power generation elements] The battery manufacturing method according to Embodiment 2 includes the steps of: cutting a flat plate containing multiple power generation elements to separate the multiple power generation elements individually; and coating the separated power generation elements. Multiple holding units for fixing or holding the power generation elements are used in the cutting and coating steps.

[0093] Below, we will first explain a flat plate containing multiple power generation elements, using Figures 6 and 7.

[0094] Figure 6 is a plan view of a flat plate 10 including a plurality of power generation elements 20 according to this embodiment. Figure 7 is a cross-sectional view of the flat plate 10 including a plurality of power generation elements 20 according to this embodiment. Figure 7 shows the cross-section along the line VII-VII in Figure 6. The power generation elements 20 are power generation elements for an all-solid-state battery.

[0095] As shown in Figures 6 and 7, the flat plate 10 includes four power generation elements 20A, 20B, 20C, and 20D. In the following, when it is not necessary to distinguish between power generation elements 20A, 20B, 20C, and 20D, such as when describing aspects common to all of them, they will be referred to as power generation element 20.

[0096] The four power generation elements 20 are arranged in a single plane and aligned in one direction. Because the four power generation elements 20 are aligned in one direction, the power generation elements 20 can be easily separated individually by cutting between two adjacent power generation elements 20. The portion between two adjacent power generation elements 20 may be the portion removed during the cutting process.

[0097] The number of power generation elements 20 contained in the plate 10 may be 2, 3, or 5 or more. Furthermore, 3 or more power generation elements 20 may be arranged in a matrix. In this case, the power generation elements 20 can be individually separated by cutting along two orthogonal directions. Since the plate 10 is an aggregate of multiple power generation elements 20, it can also be called an aggregate plate.

[0098] As shown in Figure 7, the flat plate 10 has a stacked structure of multiple unit cells 100. Each of the multiple unit cells 100 consists of an electrode active material layer 110, a counter electrode active material layer 120, and a solid electrolyte layer. It includes 130, an electrode current collector 140, and a counter electrode current collector 150. When the plate 10 is cut and the multiple power generation elements 20 are separated individually, each of the multiple power generation elements 20 will contain a stacked structure of unit cells 100.

[0099] In the example shown in Figure 7, the flat plate 10 is stacked in a configuration in which multiple unit cells 100 are electrically connected in parallel. Specifically, two adjacent unit cells 100 in the stacking direction share an electrode current collector 140 or a counter electrode current collector 150, and the arrangement of each layer is in opposite directions.

[0100] The flat plate 10 may be stacked in a configuration in which multiple unit cells 100 are electrically connected in series. Specifically, two adjacent unit cells 100 in the stacking direction may be stacked with one electrode current collector 140 and the other counter electrode current collector 150 in direct contact or via a conductive film, and the arrangement of the remaining layers may be in the same direction. In this case, two adjacent unit cells 100 may include a so-called bipolar current collector instead of a stacked structure of electrode current collector 140 and counter electrode current collector 150. Furthermore, the power generation element 20 may include multiple unit cells 100 with a combination of parallel and series connections.

[0101] The flat plate 10 may have only one unit cell 100. In this case, if the flat plate 10 is cut and the multiple power generation elements 20 are separated individually, each of the multiple power generation elements 20 will contain only one unit cell 100. That is, each of the multiple power generation elements 20 may contain one electrode active material layer 110, one counter electrode active material layer 120, one solid electrolyte layer 130, one electrode current collector 140, and one counter electrode current collector 150.

[0102] The specific configurations of the electrode active material layer 110, the counter electrode active material layer 120, the solid electrolyte layer 130, the electrode current collector 140, and the counter electrode current collector 150 will be explained later using Figures 21A to 21C.

[0103] [Holding unit] Next, the holding unit for holding the power generation element 20 will be explained using Figures 8 to 10. The holding unit can also be used as a jig for fixing the power generation element 20 contained in the flat plate 10.

[0104] Figure 8 is a schematic diagram showing the top, side, and front views of a first example of a holding unit according to this embodiment. Specifically, Figures 8(a), (b), and (c) represent the top view, left side view, and front view of the holding unit 200, respectively.

[0105] The holding unit 200 shown in Figure 8 is a holding unit of the pressing claw type. The holding unit 200 comprises a base portion 210, a support portion 220, a pressing portion 230, and an arm portion 240. The holding unit 200 can hold the power generation element 20, which is placed on the upper surface of the support portion 220, by the pressing portion 230 pressing down on the power generation element 20. The pressing portion 230 is connected to the arm portion 240. The arm portion 240 is rotatable about a predetermined axis. As the arm portion 240 rotates, the pressing portion 230 moves, applying a pressing force to the power generation element 20, thereby fixing and holding the power generation element 20.

[0106] The support portion 220 is provided with a slit-shaped opening 221 that opens to the front. The opening 221 is configured so that the support portion of another holding unit can be inserted into it. This allows for easy transfer of the power generation element 20 from one holding unit 200 to another. A specific example will be described later.

[0107] Furthermore, the support portion 220 may also be connected to the arm portion, and the power generation element 20 may be held in place by the movement of both the support portion 220 and the pressing portion 230. In other words, holding The unit 200 may be a clamping type holding unit. Alternatively, at least one of the support portion 220 and the pressing portion 230 may be configured to press down on or clamp the power generation element 20 by sliding in the vertical direction rather than rotating around an axis.

[0108] Figure 9 is a schematic diagram showing the top, side, and front views of a second example of the holding unit according to this embodiment. Specifically, Figures 9(a), (b), and (c) represent the top view, left side view, and front view of the holding unit 300, respectively. Note that in Figures 9(b) and (c), only the support portion 320, ventilation portion 330, and sealing portion 340 are shown in cross-sections passing approximately through their respective centers.

[0109] The holding unit 300 shown in Figure 9 is a vacuum suction type holding unit. The holding unit 300 comprises a base portion 310, a support portion 320, a ventilation portion 330, and a sealing portion 340. The support portion 320 is provided with a hollow space 321 with an open top. One end of the ventilation portion 330 communicates with the space 321, and the other end is connected to an intake device (not shown), such as a vacuum pump. By drawing gas from the space 321 through the ventilation portion 330, the holding unit 300 can fix and hold the power generation element 20 placed on the upper surface of the support portion 320.

[0110] The sealing portion 340 is an elastic member such as an O-ring and is provided along the perimeter of the opening on the upper side of the space 321. The sealing portion 340 prevents gas from leaking out from the gap between the power generation element 20 and the support portion 320. This increases the holding force of the power generation element 20 by the holding unit 300.

[0111] Figure 10 is a schematic diagram showing the top, side, and front views of a third example of the holding unit according to this embodiment. Specifically, Figures 10(a), (b), and (c) represent the top view, left side view, and front view of the holding unit 400, respectively. In Figures 10(b) and (c), only the support portion 420, the ventilation portion 430, and the porous adsorption member 440 are shown in cross-sections passing approximately through the center of each portion.

[0112] The holding unit 400 shown in Figure 10 is a holding unit of the porous adsorption plate type. The holding unit 400 comprises a base portion 410, a support portion 420, a ventilation portion 430, and a porous adsorption member 440. The support portion 420 is provided with a space similar to the support portion 320 of the holding unit 300 in Figure 9, and the porous adsorption member 440 is filled in this space. The porous adsorption member 440 is, for example, ceramic, but is not particularly limited.

[0113] The ventilation section 430 is connected at one end to the porous adsorption member 440 and at the other end to an intake device (not shown), such as a vacuum pump. The intake device draws gas from within the pores of the porous adsorption member 440 through the ventilation section 430, allowing the holding unit 400 to fix and hold the power generation element 20 placed on the upper surface of the porous adsorption member 440.

[0114] As described above, the holding unit can be, for example, a holding unit 200 of the pressing claw type or clamping type schematically shown in Figure 8, a holding unit 300 of the vacuum suction type schematically shown in Figure 9, or a holding unit 400 of the porous suction plate type schematically shown in Figure 10. Furthermore, the holding unit is not limited to the illustrated examples, but other types and combinations thereof can be used, and the method of holding the power generation element 20 in this disclosure is not limited to the illustrated types. For example, vacuum suction or porous suction may be applied to the upper surface of the power generation element 20. Also, if there is no risk of damage, the power generation element 20 may be held by clamping its sides.

[0115] [Battery manufacturing method] Next, the method for manufacturing the battery according to this embodiment will be explained with reference to Figures 11 to 15.

[0116] First, an overview of the battery manufacturing method will be explained using Figure 11. Figure 11 is a flowchart showing an example of a battery manufacturing method according to this embodiment.

[0117] As shown in Figure 11, first, a flat plate 10 containing multiple power generation elements 20 is prepared (S20, preparation step). Next, each of the multiple power generation elements 20 contained in the flat plate 10 is fixed (S22, fixing step). Next, the multiple power generation elements 20 are separated individually by cutting the flat plate 10 (S24, cutting step). Next, the separated multiple power generation elements 20 are held by multiple holding units whose relative positions can be changed (S26, holding step).

[0118] The subsequent processes (S12 to S18) are the same as in Embodiment 1. In this embodiment, in the step of arranging the end faces of the power generation elements in close proximity (S12), multiple holding units change the relative positions of at least two of the multiple power generation elements 20 so that they are in a position suitable for coating. That is, multiple holding units arrange the end faces of two power generation elements facing each other and in close proximity.

[0119] By following the above steps, batteries can be manufactured with high productivity and high yield. However, the battery manufacturing method described herein is not limited to the above example. For example, the fixing step and the holding step may be performed substantially simultaneously.

[0120] Next, the main steps of the manufacturing method shown in Figure 11 will be explained in detail using the diagram. The manufacturing method shown in Figure 11 is carried out, for example, by the manufacturing system 1 shown in Figure 12.

[0121] Figure 12 is a block diagram showing the configuration of the battery manufacturing system 1 according to this embodiment. As shown in Figure 12, the manufacturing system 1 comprises a plurality of holding units 200 and 300, a cutting device 500, a coating device 700, and a control unit 800.

[0122] Holding units 200 and 300 are the holding units shown in Figures 8 and 9, respectively. Manufacturing system 1 may also include holding unit 400, shown in Figure 10, instead of holding unit 200 or 300. Furthermore, all holding units in manufacturing system 1 may be of the same type.

[0123] The following describes an example of manufacturing a battery from the flat plate 10 shown in Figures 6 and 7. Since the flat plate 10 contains four power generation elements 20, four batteries can be manufactured. To fix and hold the four power generation elements 20, the manufacturing system 1 includes four holding units 200 and four holding units 300.

[0124] Figure 13 is a schematic diagram showing the fixing step (S22) of the battery manufacturing method according to this embodiment. Figure 13(a) and (b) are a top view and a side view, respectively, of the multiple holding units 200 and the cutting device 500 of the manufacturing system 1.

[0125] As shown in Figure 13, the flat plate 10 is fixed by being pressed down by multiple holding units 200 before being cut and separated into individual power generation elements 20 by the cutting device 500. Specifically, each of the four holding units 200 fixes the four power generation elements 20 contained in the flat plate 10 by pressing them down one-to-one.

[0126] Figure 14 is a schematic diagram showing the cutting step (S24) of the battery manufacturing method according to this embodiment. Figures 14(a) and (b) are a top view and a side view, respectively, of the multiple holding units 200 and the cutting device 500 of the manufacturing system 1.

[0127] The cutting device 500 shown in Figures 13 and 14 is a rotary blade type cutting device. The cutting device 500 comprises a plurality of cutting blades 510 and a shaft portion 520. The plurality of cutting blades 510 are rotatable around the shaft portion 520 and are arranged at predetermined intervals from each other. The spacing between adjacent cutting blades 510 is set depending on the size of the power generation element 20.

[0128] As shown in Figures 13 and 14, the cutting device 500 moves from the right side to the left side of the multiple holding units 200 in the figure. This allows the flat plate 10 to be cut simultaneously at three locations, separating the four power generation elements 20 individually. Alternatively, the cutting device 500 may be fixed in place while the multiple holding units 200 move.

[0129] Furthermore, the cutting device 500 is not limited to a rotary blade system, but may also be a system in which the cutting blade moves in the vertical direction (stacking direction), the horizontal direction (direction parallel to the main surface of the power generation element), or in an oblique direction. In addition, the cutting device 500 may be a device capable of cutting while vibrating, such as ultrasonic vibration. Furthermore, the cutting device 500 is not limited to mechanical cutting, but may also be a cutting device utilizing gas or a laser.

[0130] As shown in Figure 14, all of the power generation elements 20 before and after cutting are held by the corresponding holding units 200. Therefore, when the flat plate 10 is separated into multiple power generation elements 20, each power generation element 20 does not scatter and is held by the holding units 200. In other words, the relative positional relationship of the multiple power generation elements 20 is maintained before and after cutting, so damage to the power generation elements 20 due to collisions between adjacent power generation elements 20 can be suppressed.

[0131] After being separated into multiple power generation elements 20, steps may be taken to remove cutting debris, for example, by electrostatic discharge and blowing or suction. Each separated power generation element 20 is transferred from holding unit 200 to holding unit 300, as shown in Figures 14 to 15.

[0132] Figure 15 is a schematic diagram showing the holding step (S26) of the battery manufacturing method according to this embodiment. Figures 15(a) and (b) are top and side views, respectively, of the multiple holding units 200 and 300 of the manufacturing system 1.

[0133] First, as shown in Figure 14, the power generation element 20 is fixed to the holding unit 200 and held by the holding unit 300 by vacuum suction. Specifically, the support portion 320 of the holding unit 300 is inserted into the opening 221 of the support portion 220 of the holding unit 200, and the seal portion 340 is brought into contact with the lower surface of the power generation element 20. After sealing the space 321 between the power generation element 20 and the support portion 320 of the holding unit 300 with the seal portion 340, the gas in the space 321 is sucked out through the ventilation portion 330 via an intake device (not shown). By doing so, the space 321 is reduced in pressure, allowing the power generation element 20 to be attracted to the support portion 320, so that the holding unit 300 can hold the power generation element 20.

[0134] After the holding unit 300 has held the power generation element 20, the fixing by the holding unit 200 is released. Specifically, as shown in Figure 15, the arm portion 240 is rotated to pull the pressing portion 230 away from the support portion 220. This keeps the power generation element 20 held by the holding unit 300. The power generation element 20 can be separated from the holding unit 200 by sliding the holding unit 200 or 300 to pull the support portion 320 out of the opening 221.

[0135] Thus, the control of the positional relationship between the power generation elements 20 after cutting is taken over from the holding unit 200 to the holding unit 300. By using the holding unit 200 with a clamping claw type during cutting and then taking over the holding method to the holding unit 300 with an adsorption type, it is possible to suppress the adhesion of cutting dust to the adsorption type holding unit 300 and the resulting decrease in adsorption performance. Note that the method of changing the control of the positional relationship between each power generation element 20 between processes is not limited to the example described above.

[0136] For the multiple power generation elements 20 held by the holding unit 300, a coating process (S12-S18) is performed on the end faces. In this embodiment, a coating film is formed simultaneously on each end face of the four power generation elements 20.

[0137] Figures 16 and 17 are schematic diagrams showing the coating process of the battery manufacturing method according to this embodiment. Figures 16 and 17(a) and (b) are top and side views, respectively, of the multiple holding units 300 and the coating apparatus 700.

[0138] As shown in Figure 16, the multiple holding units 300 adjust the positional relationship between the power generation elements 20 so that the end faces of each power generation element 20 face each other and are close together. The distance between adjacent power generation elements 20 is, for example, 0.05 mm or more, but may be 0.1 mm or more. Also, the distance between adjacent power generation elements 20 is, for example, 2 mm or less, but may be 1 mm or less. Note that the distance between adjacent power generation elements 20 is not limited to this numerical range, and an appropriate distance range can be selected depending on the characteristics of the coating liquid 30 used for end face coating, specifically its viscosity.

[0139] Multiple holding units 300 reduce the gap between two adjacent power generation elements 20, allowing the applied coating liquid 30 to penetrate the gap between the power generation elements 20 even when the direction of application of the coating liquid 30 from the coating apparatus 700 is nearly perpendicular to the main surface of the power generation elements 20, as shown in (b) of Figures 16 and 17. As a result, an insulating layer, which is a coating layer, can be formed on the end faces of the power generation elements 20. The direction of application of the coating liquid 30 is centered on the direction perpendicular to the main surface of the power generation elements 20, for example, within a range of -45 degrees to +45 degrees. For the purpose of miniaturizing the equipment, it may also be within a range of -15 degrees to +15 degrees.

[0140] In this embodiment as well, as shown in Figures 4 and 5, adjacent power generation elements 20 may be moved relative to each other in order to further homogenize the coating on the end faces of the power generation elements 20. Specifically, by changing the distance between the end faces of adjacent power generation elements 20 while the coating liquid 30 is applied to the close proximity of the end faces between adjacent power generation elements 20, the coating liquid 30 can be applied to the end faces of the power generation elements 20 more quickly. The change in distance can be by bringing them closer together, moving them further apart, or repeating these actions. Alternatively, the power generation elements 20 may be slid along the end faces of adjacent power generation elements 20. This allows the coating liquid 30 to be applied more uniformly to the end faces of the power generation elements 20.

[0141] Furthermore, the coating may be applied to each of the four sides of the power generation element 20, which has a rectangular shape in plan view. In this case, the holding unit 300 can rotate the power generation element 20 to align the end face of the object to be coated with the coating device 700. An example of rotating the power generation element 20 will be explained later.

[0142] Furthermore, before applying the coating liquid 30 to the end face of the power generation element 20, a polishing step and a cleaning step of the end face may be performed.

[0143] For example, in the polishing process, the ends of the power generation elements 20, which are arranged at predetermined intervals from each other, By placing a rotatable grinding wheel between the surfaces and rotating the grinding wheel, the end faces of each of the multiple power generation elements 20 can be polished simultaneously. This makes it possible to remove burrs and irregularities in the cut surface generated by the cutting device 500 in the previous process. The grinding wheel does not have to be rotatable; it may move in the vertical direction (stacking direction), the horizontal direction (parallel to the main surface of the power generation element), or diagonally. The movement of the grinding wheel may be unidirectional, and may be one or more reciprocating movements. The grinding wheel may also vibrate.

[0144] Furthermore, it is possible to remove the abrasive powder from the end face polished by the grinding wheel through a cleaning process. The method of removal is not particularly limited, but one efficient method is to wipe the end face located at a 90-degree angle to the grinding surface using a non-woven fabric or the like.

[0145] The power generation element 20, which has a coating formed on its end face, is enclosed in a container made of laminate film arranged on its upper and lower surfaces, for example, and the laminate films on the upper and lower surfaces of the power generation element 20 are heat-fused together in the heat-fusion region around the power generation element 20. At this time, lead members for taking out the positive electrode and negative electrode can be connected to the main surfaces of the electrode current collector 140 and the counter electrode current collector 150 and guided to the outside of the laminate film through the heat-fusion region. This allows the power generation element 20 to be charged and discharged from the outside of the laminate film.

[0146] As described above, a battery can be manufactured comprising a power generation element 20, a laminate film that seals the power generation element 20, a lead member for the positive electrode, and a lead member for the negative electrode. Note that the battery does not necessarily have to include the laminate film and the lead members.

[0147] [Change the relative positions] Next, we will explain the process of changing the positions of the multiple power generation elements 20 (S12).

[0148] The relative positions of the multiple power generation elements 20 are changed by the holding units 300 that hold the power generation elements 20. The relative positions of the multiple holding units 300 can be changed. As a way to change the relative positions of the holding units 300, for example, their relative positions are mechanically restricted by a sliding mechanism, a link mechanism and / or a gear mechanism connected to each of the multiple base portions 310.

[0149] Alternatively, each of the multiple holding units 300 may have its own individual drive mechanism. For example, each of the multiple holding units 300 comprises a control unit such as a microcontroller and a drive unit such as a motor that is driven based on a control signal transmitted from the control unit. By coordinating the control signals of each of the multiple holding units 300, the relative positions of the holding units 300 can be changed. The method for changing and controlling the relative positions of the holding units 300 is not limited to these means. Although the holding unit 300 has been used as an example here, the relative positions of the holding units 200 and 400 can also be changed in the same way.

[0150] The multiple holding units 300 are controlled, for example, by the control unit 800 shown in Figure 12. The control unit 800 is implemented, for example, by an integrated circuit (IC), specifically an LSI (Large Scale Integration). Note that the integrated circuit is not limited to an LSI; it may also be a dedicated circuit or a general-purpose processor. For example, the control unit 800 may be a microcontroller.

[0151] The control unit 800 includes, for example, a non-volatile memory where the program is stored, input / output ports, and a processor that executes the program. The control unit 800 also includes a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor in which the connections and settings of circuit cells within the LSI can be reconfigured. It may also be the case that the control unit 800 performs functions that may be implemented in software or in hardware.

[0152] For example, the control unit 800 outputs numerical information to each of the multiple holding units 300. The numerical information indicates the amount of change in the position of each corresponding holding unit 300. Alternatively, the numerical information may be three-dimensional coordinates representing the position of the corresponding holding unit 300 in three-dimensional space. The microcontroller of the holding unit 300 that receives the numerical information outputs a control signal to the drive unit based on the numerical information, thereby moving the holding unit 300.

[0153] Multiple holding units 300 can change at least one of the planar position, height, and rotation angle of the power generation element 20 they hold. Specifically, the positional relationship of the power generation element 20 is changed by moving or rotating the entire holding unit 300 in the planar direction or in the height direction. The base portion 310 of the holding unit 300 may be fixed, and the support portion 320 may move or rotate in the planar direction or in the height direction. As long as the positional relationship between the multiple power generation elements 20 can be changed, the specific configuration of the multiple holding units 300 is not particularly limited. The planar direction is the direction parallel to the main surface of the flat power generation element 20. The height direction is the direction perpendicular to the main surface of the flat power generation element 20.

[0154] Figures 18 to 20 are schematic diagrams showing the first to third examples of the process for changing the positional relationship between the power generation elements 20 in the battery manufacturing method according to this embodiment. In each figure, (a) and (b) are the top view and front view of the power generation elements 20 and the holding unit 300 before the change in positional relationship, respectively. (c) and (d) are the top view and front view of the power generation elements 20 and the holding unit 300 after the change in positional relationship, respectively. In Figures 18 to 20, the power generation elements are labeled with reference numerals "20A" to "20D" to clarify the positional relationship of the power generation elements 20. The reference numeral "20" is omitted to avoid making the drawings complex.

[0155] As shown in Figure 18, the multiple holding units 300 are movable in the planar direction. Therefore, the distance between adjacent power generation elements 20 separated from the flat plate 10 can be uniformly changed from distance d1 to distance d2. This allows the distance between adjacent power generation elements 20 to be changed all at once to a distance suitable for the next process (specifically, polishing). By changing the distance all at once, the position of multiple power generation elements 20 can be changed simply, quickly, and reliably.

[0156] Note that Figure 18 shows an example in which multiple holding units 300 widen the distance between adjacent power generation elements 20 from distance d1 to distance d2 (>d1), but the system is not limited to this. Multiple holding units 300 may also narrow the distance between adjacent power generation elements 20. Furthermore, the distance between power generation elements 20 does not have to be uniform.

[0157] Furthermore, as shown in Figure 19, the multiple holding units 300 are movable in the height direction. Therefore, the height relationship between adjacent power generation elements 20 separated from the flat plate 10 can be changed simultaneously according to a certain rule. Having a controlled degree of freedom in the positional relationship in the height direction allows for a more compact design of the process equipment. For example, as shown in Figures 19 and 20, the power generation elements 20 are moved so that the heights of adjacent power generation elements 20 are staggered. When rotating multiple power generation elements 20 simultaneously, collisions between the power generation elements 20 can be suppressed. This allows for a more compact design of the process equipment compared to cases where a large distance is secured in the planar direction. As a result, for example, a significant cost reduction is possible in processes that handle a large number of power generation elements 20.

[0158] In Figure 19, an example is shown where, in the direction of arrangement of the power generation elements 20, all odd-numbered power generation elements 20 have the same height, all even-numbered power generation elements 20 have the same height, and the heights of odd-numbered and even-numbered elements are different, but the arrangement is not limited to this. Multiple holding units 300 can also cause all of the multiple power generation elements 20 to have different heights. The rotation angles shown in Figure 20 may also be different for all of the power generation elements 20.

[0159] As described above, the positional relationship of the holding unit 300 that holds the multiple power generation elements 20 is adjustable. Therefore, when performing the coating shown in Figures 16 and 17, first, as shown in Figure 12, the distance between the end faces of the power generation elements 20 immediately after separation can be adjusted to a distance suitable for coating.

[0160] Furthermore, for example, if the power generation element 20 is in the shape of a rectangular flat plate, after forming a coating on the end faces of adjacent power generation elements 20, the multiple holding units 300 alternately shift the height at which they hold the power generation elements 20, as shown in Figure 19, and then rotate the power generation elements 20 by 90 degrees. After that, the spacing between the holding units 300 is adjusted, and the holding heights of the power generation elements 20 are aligned again. Then, by applying the coating liquid 30 again with the coating device 700, a coating can be formed on each of the four sides of the rectangular power generation element 20.

[0161] [Unit cell] Next, we will describe the specific configuration of each layer of the unit cell 100 that the power generation element 20 described in each of the embodiments above contains.

[0162] Figures 21A to 21C are cross-sectional views showing examples of the schematic configuration of a unit cell 100 included in the power generation element 20 according to each embodiment. As shown in Figure 21A, the unit cell 100 includes an electrode active material layer 110, a counter electrode active material layer 120, a solid electrolyte layer 130, an electrode current collector 140, and a counter electrode current collector 150. The electrode active material layer 110 and the counter electrode active material layer 120 face each other via the solid electrolyte layer 130.

[0163] The laminated structure of the electrode current collector 140 and the electrode active material layer 110 is an example of a negative electrode plate. The laminated structure of the counter electrode current collector 150 and the counter electrode active material layer 120 is an example of a positive electrode plate. The solid electrolyte layer 130 is an example of an intermediate layer located between the positive electrode plate and the negative electrode plate. Note that, as shown in Figures 21B and 21C, the unit cell 100 does not necessarily have to include at least one of the electrode current collector 140 and the counter electrode current collector 150. In other words, the negative electrode plate may consist only of the electrode active material layer 110, and the positive electrode plate may consist only of the counter electrode active material layer 120.

[0164] The electrode active material layer 110 is, for example, a layer containing a negative electrode material as an electrode material. For example, the electrode active material layer 110 contains a negative electrode active material. As the negative electrode active material contained in the electrode active material layer 110, for example, graphite, metallic lithium, etc., can be used. As the material for the negative electrode active material, various materials that can release and insert ions such as lithium (Li) or magnesium (Mg) can be used.

[0165] Furthermore, as the material containing the electrode active material layer 110, a solid electrolyte such as an inorganic solid electrolyte may be used. As an inorganic solid electrolyte, for example, a sulfide solid electrolyte or an oxide solid electrolyte may be used. As a sulfide solid electrolyte, for example, a mixture of lithium sulfide (Li2S) and phosphorus pentasulfide (P2S5) may be used. In addition, as the material containing the electrode active material layer 110, a conductive material such as acetylene black, or a binding binder such as polyvinylidene fluoride may be used.

[0166] The electrode active material layer 110 can be manufactured by coating and drying a paste-like coating, which is made by kneading the materials containing the electrode active material layer 110 together with a solvent, onto the surface of the electrode current collector 140. To increase the density of the material layer 110, the electrode plate containing the electrode active material layer 110 and the electrode current collector 140 may be pressed after drying. The thickness of the electrode active material layer 110 is, for example, 5 μm or more and 300 μm or less, but is not limited to this.

[0167] The counter electrode active material layer 120 is, for example, a layer containing a positive electrode material as an electrode material. The positive electrode material is the material that constitutes the counter electrode of the negative electrode material. For example, the counter electrode active material layer 120 contains a positive electrode active material. Possible positive electrode active materials to be contained in the counter electrode active material layer 120 include, for example, lithium cobalt oxide composite oxide (LCO), lithium nickel oxide composite oxide (LNO), lithium manganese oxide composite oxide (LMO), lithium-manganese-nickel composite oxide (LMNO), lithium-manganese-cobalt composite oxide (LMCO), lithium-nickel-cobalt composite oxide (LNCO), and lithium-nickel-manganese-cobalt composite oxide (LNMCO). Various materials that can release and insert ions such as Li or Mg can be used as the material for the positive electrode active material.

[0168] Furthermore, as the material containing the counter electrode active material layer 120, a solid electrolyte such as an inorganic solid electrolyte may be used. As the inorganic solid electrolyte, sulfide solid electrolytes or oxide solid electrolytes may be used. As the sulfide solid electrolyte, for example, a mixture of Li2S and P2S5 may be used. The surface of the positive electrode active material may be coated with a solid electrolyte. Furthermore, as the material containing the counter electrode active material layer 120, a conductive material such as acetylene black, or a binding binder such as polyvinylidene fluoride may be used.

[0169] The counter electrode active material layer 120 can be manufactured by coating the surface of the counter electrode current collector 150 with a paste-like coating made by kneading the materials containing the counter electrode active material layer 120 together with a solvent, and then drying the coating. To increase the density of the counter electrode active material layer 120, the counter electrode plate containing the counter electrode active material layer 120 and the counter electrode current collector 150 may be pressed after drying. The thickness of the counter electrode active material layer 120 is, for example, 5 μm to 300 μm, but is not limited to this.

[0170] The solid electrolyte layer 130 is placed between the electrode active material layer 110 and the counter electrode active material layer 120. The solid electrolyte layer 130 is in contact with both the electrode active material layer 110 and the counter electrode active material layer 120. The solid electrolyte layer 130 is a layer containing an electrolyte material. As the electrolyte material, a generally known solid electrolyte for batteries can be used. The thickness of the solid electrolyte layer 130 may be 5 μm or more and 300 μm or less, or 5 μm or more and 100 μm or less.

[0171] As the solid electrolyte, for example, an inorganic solid electrolyte may be used. As the inorganic solid electrolyte, sulfide solid electrolytes or oxide solid electrolytes may be used. As the sulfide solid electrolyte, for example, a mixture of Li2S and P2S5 may be used. In addition to the electrolyte material, the solid electrolyte layer 130 may also contain a binding binder such as polyvinylidene fluoride.

[0172] The electrode current collector 140 and the counter electrode current collector 150 are each conductive foil-shaped, plate-shaped, or mesh-shaped members. The electrode current collector 140 and the counter electrode current collector 150 may each be, for example, a conductive thin film. As materials for constituting the electrode current collector 140 and the counter electrode current collector 150, metals such as stainless steel (SUS), aluminum (Al), copper (Cu), and nickel (Ni) may be used. The electrode current collector 140 and the counter electrode current collector 150 may be formed using different materials.

[0173] The thickness of the electrode current collector 140 and the counter electrode current collector 150 is, for example, 5 μm to 100 μm, but is not limited to this. The electrode active material layer 110 is in contact with the main surface of the electrode current collector 140. The electrode current collector 140 is provided in the portion that is in contact with the electrode active material layer 110. Furthermore, it may include a current collector layer which contains a conductive material. The main surface of the counter electrode current collector 150 is in contact with the counter electrode active material layer 120. The counter electrode current collector 150 may also include a current collector layer which contains a conductive material, provided in the portion that is in contact with the counter electrode active material layer 120.

[0174] In the power generation element 20, the electrode active material layer 110, the counter electrode active material layer 120, the solid electrolyte layer 130, the electrode current collector 140, and the counter electrode current collector 150 are maintained in a parallel plate shape. This suppresses the occurrence of cracks or collapse due to bending. Alternatively, the electrode active material layer 110, the counter electrode active material layer 120, the solid electrolyte layer 130, the electrode current collector 140, and the counter electrode current collector 150 may be smoothly curved together.

[0175] As shown in Figure 21A, the unit cell 100 includes one electrode current collector 140 and one counter electrode current collector 150, but is not limited to this. As shown in unit cell 100B in Figure 21B, the unit cell 100 does not need to include the counter electrode current collector 150. Alternatively, as shown in unit cell 100C in Figure 21C, the unit cell 100 does not need to include the electrode current collector 140.

[0176] For example, the power generation elements shown in Figures 1 and 2 are formed by stacking unit cells 100A, 100B, or 100C shown in Figures 21A to 21C in appropriate combinations. Depending on the combination, adjacent electrode current collectors 140 may be stacked together, adjacent counter electrode current collectors 150 may be stacked together, or two adjacent electrode current collectors 140 and two counter electrode current collectors 150 may be stacked together. Two stacked current collectors may be joined together, for example, via a conductive material or adhesive material.

[0177] (Other embodiments) Although a battery manufacturing method and battery manufacturing system according to one or more embodiments have been described above based on embodiments, this disclosure is not limited to these embodiments. Within the scope of this disclosure, various modifications to these embodiments that a person skilled in the art could conceive, as well as configurations constructed by combining components from different embodiments, are also included, as long as they do not depart from the spirit of this disclosure.

[0178] For example, while each embodiment shows an example where the coating liquid is formed using an insulating material, it is not limited to this. The coating liquid may be formed using a conductive material. Specifically, the coating liquid may be a conductive paste. For example, the end faces of the two power generation elements to be prepared may already be insulated, and in the coating process, a conductive coating film may be formed using a conductive coating liquid. The conductive coating film is used for electrical connection or electrical extraction between battery cells contained in the power generation elements.

[0179] For example, while each embodiment shows an example in which the power generation element includes a battery cell, it is not limited to this. The power generation element may include only a portion related to at least one of the positive electrode and the negative electrode. Specifically, the power generation element may be a positive electrode plate or a negative electrode plate. The positive electrode plate is a flat plate that includes a positive electrode current collector and a positive electrode active material layer, but does not include a negative electrode current collector and a negative electrode active material layer. The negative electrode plate is a flat plate that includes a negative electrode current collector and a negative electrode active material layer, but does not include a positive electrode current collector and a positive electrode active material layer. Both the positive electrode plate and the negative electrode plate may include a solid electrolyte layer.

[0180] Furthermore, while each embodiment shows an example in which the power generation element includes a solid electrolyte layer as an intermediate layer, it is not limited to this. The power generation element may include a separator as an intermediate layer and may include an electrolyte instead of a solid electrolyte. In other words, the power generation element is not limited to a power generation element for an all-solid-state battery.

[0181] Furthermore, each of the multiple power generation elements fixed before the plate is cut is the smallest size battery element. This is not required. The smallest battery element means a power generation element equivalent in size to the battery that will ultimately be manufactured. That is, each of the multiple power generation elements fixed before the plate is cut may contain two or more smallest battery elements.

[0182] For example, consider a flat plate in which eight minimum-sized battery elements are arranged in a two-dimensional configuration of 4 rows and 2 columns. By cutting the flat plate in three places, it may be separated into four power generation elements, each containing two minimum-sized battery elements. The four power generation elements correspond to each row of the flat plate before cutting. Subsequently, by cutting each of the four power generation elements, they may be separated into two minimum-sized battery elements. In this way, when the flat plate is cut multiple times, the battery manufacturing method and manufacturing system according to this disclosure may be applied to the cutting process in a stage prior to the final cut.

[0183] Furthermore, while Embodiment 2 described an example in which the fixing of multiple power generation elements contained in a flat plate and the holding of multiple power generation elements during coating are performed by different holding units, the invention is not limited to this. For example, the holding units that hold the power generation elements contained in the flat plate may change their relative positions to hold the power generation elements during coating. This reduces the number of units that hold the power generation elements, thereby enabling a compact manufacturing system.

[0184] Furthermore, while Embodiment 2 shows an example where coating is applied to all power generation elements separated from the flat plate, the invention is not limited to this. For example, coating may be applied to only two of the multiple power generation elements separated from the flat plate. In this case, the positional relationship change process performed by the holding unit may also be performed only on those two power generation elements.

[0185] Furthermore, while each embodiment shows an example where the power generation element is a rectangular flat plate, it is not limited to this. For example, the planar shape of the power generation element may be a polygon other than a rectangle, such as a circle or an ellipse. The shape of the power generation element may also be a curved plate. Alternatively, the shape of the power generation element may be a block shape, such as a cube.

[0186] Furthermore, each of the above embodiments can be modified, replaced, added, or omitted in various ways within the scope of the claims or their equivalents. [Industrial applicability]

[0187] The battery manufacturing method and battery manufacturing system described herein can be used as a battery manufacturing method and battery manufacturing system for electronic devices, electrical appliances, electric vehicles, and the like. [Explanation of Symbols]

[0188] 1. Manufacturing System 10 flat plate 20, 20A, 20B, 20C, 20D power generation elements 21A, 21B end face 22 gaps 30 Coating liquid 30A, 30B coating 100, 100A, 100B, 100C unit cells 110 Electrode active material layer 120 Counter electrode active material layer 130 Solid electrolyte layer 140 Electrode current collector 150 Counter-pole current collector 200, 300, 400 holding units 210, 310, 410 Base section 220, 320, 420 Support part 221 Opening 230 Pressing part 240 Arm section 321 Space 330, 430 Ventilation section 340 Seal part 440 Porous adsorption material 500 cutting equipment 510 cutting blade 520 Shaft section 700 Coating equipment 800 Control Unit 900 Curing equipment

Claims

1. The process involves arranging two power generation elements with their end faces facing each other and within a first distance of each other, A step of applying a coating liquid to the adjacent portions of the end faces, The process includes applying the coating liquid and then separating the end faces from each other by a second distance or more that is longer than the first distance, thereby forming a coating film on each end face of the two power generation elements. Battery manufacturing method.

2. After applying the coating liquid, the process includes bringing the end faces closer together before separating them by a distance greater than or equal to the second distance. A method for manufacturing a battery according to claim 1.

3. After applying the coating liquid, the process includes separating the end faces by a distance less than the second distance before bringing the end faces together. A method for manufacturing a battery according to claim 2.

4. After applying the coating liquid, the process includes sliding the end faces together before separating them by a distance greater than or equal to the second distance. A method for manufacturing a battery according to any one of claims 1 to 3.

5. The direction in which the end faces slide against each other is parallel to the main surface of the power generation element. A method for manufacturing a battery according to claim 4.

6. The direction in which the coating liquid is applied in the aforementioned application step is within the range of -45° to +45°, centered on the direction perpendicular to the main surface of the power generation element. A method for manufacturing a battery according to any one of claims 1 to 3.

7. A process of fixing each of the multiple power generation elements contained in the flat plate, The process involves cutting the flat plate to separate the multiple power generation elements individually, The process includes: holding the plurality of power generation elements with a plurality of holding units whose relative positions can be changed, The two power generation elements are two of the multiple power generation elements held by the multiple holding units, Each of the above-mentioned steps of arranging and forming is performed by two holding units that hold the two power generation elements. A method for manufacturing a battery according to any one of claims 1 to 3.

8. The aforementioned fixing step is performed using a jig different from the plurality of holding units. The holding process is performed by the plurality of holding units while the jig is fixing each of the plurality of power generation elements. A method for manufacturing a battery according to claim 7.

9. The aforementioned fixing process is performed by the plurality of holding units. A method for manufacturing a battery according to claim 7.

10. The holding process is carried out by pressing down, clamping, or adsorbing each of the multiple power generation elements. A method for manufacturing a battery according to claim 7.

11. The plurality of holding units are capable of changing at least one of the planar position, height, and rotation angle of the power generation element they hold. A method for manufacturing a battery according to claim 7.

12. The plurality of holding units change at least one of the planar position, height, and rotation angle of the power generation element they hold during the period in which the coating liquid is applied. A method for manufacturing a battery according to claim 7.

13. The plurality of holding units change at least one of the planar position, height, and rotation angle of the power generation element they hold, based on numerical information output from the control unit. A method for manufacturing a battery according to claim 7.

14. The power generation element includes a positive electrode plate, a negative electrode plate, and an intermediate layer located between the positive electrode plate and the negative electrode plate. A method for manufacturing a battery according to any one of claims 1 to 3.

15. The aforementioned power generation element is a power generation element for an all-solid-state battery. A method for manufacturing a battery according to any one of claims 1 to 3.

16. Two holding units that hold two power generation elements, and whose relative positions can be changed, A coating apparatus for forming a coating film on each of the two end faces of the aforementioned power generation elements, The system includes a control unit that controls the two holding units to change the relative positions of the two power generation elements, The two holding units are arranged so that the end faces of the two power generation elements face each other and are in close proximity within a first distance. The coating apparatus applies coating liquid to the portions adjacent to the end faces, The two holding units, after the coating liquid has been applied, separate the end faces from each other by a second distance or more that is longer than the first distance. Battery manufacturing system.

17. The direction in which the coating apparatus applies the coating liquid is inclined with respect to the direction perpendicular to the main surface of the power generation element. A battery manufacturing system according to claim 16.

18. The end faces are connected by the coating liquid before they are separated by the second distance or more after the coating liquid has been applied. A battery manufacturing system according to claim 16.

19. A cutting device that cuts a flat plate while each of the multiple power generation elements contained in the flat plate is fixed, thereby separating the multiple power generation elements individually, The system comprises a plurality of holding units that hold the plurality of power generation elements and whose relative positions can be changed, The two holding units are two of the plurality of holding units. A battery manufacturing system according to any one of claims 16 to 18.

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