Restraint tool, cell system, and flight body

Abstract

To provide a restraint tool for restraining a lithium metal battery including a plurality of battery cells having a structure for appropriately adjusting restraint pressure to the lithium metal battery.SOLUTION: A restraint tool includes: a restraining member 220 including a frame member 230 and a plurality of units 240 arranged on an inner side of the frame member and made of a rubber-based material, each of the plurality of units each including at least one protrusion 260, and at least one unit among the plurality of units being arranged in a direction different from other units; and a fixing member for fixing the plurality of units in a state of being pressed against a lithium metal battery 100 to be applied with pressure. Each of the plurality of units includes a planar base part 250 and at least one protrusion 260 protruding in a depth direction of the base part from the base part. A length of the protrusion along a first direction parallel with a flat surface of the base part is different from a length along a second direction parallel with a flat surface different form the first direction.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a restraint device, a battery system, and an aircraft.

Background Art

[0002] Patent Document 1 describes that in a lithium-ion battery, a plurality of stacked battery cells are sandwiched by metal plates, and the metal plates are restrained using metal bands, thereby applying a restraint pressure in the stacking direction to the battery cells. [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent Application Laid-Open No. 2022-075152

Summary of the Invention

Means for Solving the Problems

[0003] According to an embodiment of the present invention, a restraint device is provided. The restraint device may restrain a lithium metal battery including a plurality of battery cells. The restraint device may include a frame member. The restraint device may have a restraint member made of a rubber-based material and including a plurality of units disposed inside the frame member, each of the plurality of units including at least one protrusion, and at least one of the plurality of units being arranged in a direction different from that of other units. The restraint device may include a fixing member that fixes the plurality of units in a state of being pressed against and pressurized to the lithium metal battery.

[0004] In the restraint device, each of the plurality of units may have a planar base. Each of the plurality of units may have at least one protrusion protruding from the base in the thickness direction of the base. The length of the protrusion along a first direction parallel to the plane of the base and the length along a second direction parallel to the plane different from the first direction may be different. The base may be square. Each of the plurality of units may have a plurality of the protrusions arranged in the same orientation in a plurality of rows and a plurality of columns on the square base. The base may be hexagonal.

[0005] In any of the restraint devices, the protrusion may have a hollow portion opening toward the side of the base. The protrusion may have a curved shape on the top surface opposite to the side of the base.

[0006] According to an embodiment of the present invention, a restraint device is provided. The restraint device may restrain a lithium metal battery including a plurality of battery cells. The restraint device may include a restraint member. The restraint member may be a rubber-based material and may have a plate-shaped member having a plate-shaped base and a plurality of protrusions on the base. The restraint member may have a frame member into which the plate-shaped member is fitted. The restraint device may include a fixing member that fixes the plurality of protrusions of the plate-shaped member fitted into the frame member in a state of being pressed against the lithium metal battery. At least any one of the plurality of protrusions may have a hole portion on the top surface pressed against the lithium metal battery.

[0007] At least any one of the plurality of protrusions may have the hole portion at the center of the top surface. The plurality of protrusions may have the hole portion on the top surface.

[0008] According to an embodiment of the present invention, a battery system including the restraint device and the lithium metal battery is provided. According to an embodiment of the present invention, an aircraft including the battery system and a propulsion force generating device that generates a propulsion force using the electrical energy stored in the battery system is provided.

[0009] Note that the above summary of the invention does not list all of the necessary features of the present invention. Also, sub - combinations of these groups of features may also be inventions.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

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Embodiments for Carrying Out the Invention

[0011] Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution means of the invention.

[0012] A lithium-ion battery can obtain sufficient battery characteristics by being constrained at a pressure of about 0.0 to 0.2 MPa, without pressure or at low pressure. On the other hand, when a lithium metal battery is constrained at the same pressure as in the case of a lithium-ion battery, it has been found that the cycle life deteriorates. By increasing the restraint pressure by a method such as metal plate restraint using a metal plate, the cycle life is improved, but the restraint member becomes heavy and the weight energy density decreases. Also, although the thickness of the lithium metal battery changes during charge and discharge, in metal plate restraint, the pressure cannot be adjusted appropriately, so there is a possibility that the restraint pressure on the lithium metal battery may become excessive or insufficient. Also, even when the thickness of the lithium metal battery changes, it is important to suppress the slide of the lithium metal battery and stably constrain it. The restraint tool 200 according to the present embodiment has a structure that is lighter in weight compared to metal plate restraint etc., and when the thickness of the lithium metal battery changes due to charge and discharge, the restraint pressure on the lithium metal battery is appropriately adjusted. Also, it has a structure that can appropriately suppress the slide of the lithium metal battery 100.

[0013] FIG. 1 and FIG. 2 schematically show an example of the battery system 10. The battery system 10 includes a lithium metal battery 100 and a restraint tool 200. The lithium metal battery 100 includes a plurality of battery cells 110. The plurality of battery cells 110 are arranged side by side.

[0014] The restraint tool 200 restrains the lithium metal battery 100. The restraint tool 200 may restrain the lithium metal battery 100 along the direction in which the plurality of battery cells 110 are arranged side by side.

[0015] In the examples shown in FIGS. 1 and 2, the restraint 200 has a fixing member 210 and a restraint member 220. The fixing member 210 fixes the lithium metal battery 100 in a state where it is sandwiched and pressurized by the restraint member 220.

[0016] In the examples shown in FIGS. 1 and 2, the restraint 200 has the restraint members 220 on both left and right sides of the lithium metal battery 100 in the lateral direction. Note that the restraint 200 may have the restraint member 220 on only one side instead of on both left and right sides of the lithium metal battery 100 in the lateral direction. For example, in this case, on the side opposite to the side where the restraint member 220 of the lithium metal battery 100 is located, a member formed of a material having a relatively high hardness and a relatively low weight, such as a carbon fiber reinforced plastic (CFRP), is disposed. Then, the fixing member 210 fixes the lithium metal battery 100 in a state where the restraint member 220 is pressed against the lithium metal battery 100 and pressurized. The fixing member 210 may fix the lithium metal battery 100 in a state where it is sandwiched and pressurized by the member disposed on the side opposite to the side where the restraint member 220 of the lithium metal battery 100 is located and the restraint member 220.

[0017] In the present embodiment, the case where the restraint 200 includes the restraint members 220 on both left and right sides of the lithium metal battery 100 in the lateral direction will be mainly described as an example.

[0018] The restraining member 220 includes a plurality of units 240 and a frame member 230. The plurality of units 240 are arranged inside the frame member 230. In FIG. 2, an example is shown in which the restraining member 220 has two rows of units 240 in the vertical direction, but the number and arrangement of the units 240 are not limited thereto. For example, the restraining member 220 may have three or more rows of units 240. Similarly, the restraining member 220 may have a plurality of columns of units 240 in the horizontal direction. The restraining member 220 may have a single row of a plurality of columns of units 240, or may have a plurality of rows of a single column of units 240. The plurality of units 240 may be arranged side by side in contact with each other. Thereby, the plurality of units 240 are fixed without shifting within the frame member 230, contributing to stably restraining the lithium metal battery 100 within the battery system 10.

[0019] The plurality of units 240 may be fixed inside the frame member 230. For example, the plurality of units 240 are adhered and fixed inside the frame member 230 with an adhesive or the like. For example, a recess or the like is provided on the side of the plurality of units 240 in contact with the frame member 230, and a convex portion or the like having a corresponding shape is provided at a corresponding position on the side of the frame member 230 in contact with the plurality of units 240, and the convex portion or the like fits into the recess or the like to be fixed. Thereby, the plurality of units 240 are fixed without shifting within the frame member 230, contributing to stably restraining the lithium metal battery 100 within the battery system 10.

[0020] When the plurality of units 240 are fixed inside the frame member 230, the plurality of units 240 may be arranged inside the frame member 230 with a space therebetween. In this case, the intervals between the plurality of units 240 may be equal. Thereby, the plurality of units 240 are fixed without shifting within the frame member 230, contributing to stably restraining the lithium metal battery 100 within the battery system 10, and at the same time, reducing the weight of the entire battery system 10 by the amount of the plurality of units 240 arranged with a space therebetween, and improving the weight energy density. In the following embodiments, mainly the case where the units 240 are arranged side by side in contact with each other without a space therebetween will be described.

[0021] The plurality of units 240 may be made of a rubber material. Specific examples of the material of the unit 240 include, but are not limited to, ethylene propylene diene monomer (EPDM). Other examples include natural rubber, styrene butadiene rubber, nitrile rubber, butyl rubber, chloroprene rubber, chlorosulfonated polyethylene rubber, acrylic rubber, silicone rubber, and fluororubber, etc., but it may be other than these.

[0022] The plurality of units 240 can be manufactured by molding a rubber material in various ways. The molding method of the rubber material may be appropriately selected according to the type of material, desired physical properties, required production capacity, etc., and is not particularly limited. As a specific example, direct pressure molding, injection molding, injection molding, extrusion molding, etc. using a mold can be mentioned. As another specific example, it may be molded by 3D printing of a thermoplastic elastomer or the like without using a mold. A plate-like rubber may be cut with a blade or a laser to obtain a desired shape. By manufacturing a plurality of units 240 by these molding methods and arranging them in the frame member 230, the restraint device 200 can be manufactured.

[0023] At least one of the plurality of units 240 is arranged in a different orientation from the other units 240. Only one unit 240 may be arranged in a different orientation from the other units 240. For example, only one of the plurality of units 240 is arranged in a direction different from all the other remaining units 240, and each of the other remaining units 240 is arranged in the same direction as each other. For example, some of the plurality of units 240 are arranged in a direction different from all the other remaining units 240, and each of the other remaining units 240 is arranged in the same direction as each other. For example, each of the plurality of units 240 is arranged so as to have a different orientation from the adjacent unit 240.

[0024] FIG. 3 schematically shows an example of the unit 240. Each of the plurality of units 240 includes at least one protrusion 260. In FIG. 3, an example is shown in which the unit 240 includes a total of nine protrusions 260 arranged in 3 rows by 3 columns, but the arrangement and number of the protrusions 260 are not limited to this. Each of the plurality of units 240 may include one protrusion 260. Each of the plurality of units 240 may include 2, 3, 4, 5, 6, 7, or 8 protrusions 260. Each of the plurality of units 240 may include 10 or more protrusions 260. The arrangement of the plurality of units 240 may be any arrangement as long as it can appropriately adjust the restraint pressure on the lithium metal battery 100, suppress the sliding of the lithium metal battery 100 within the battery system 10, and stably restrain it. The plurality of units 240 may be arranged in a plurality of rows and / or a plurality of columns. The plurality of units 240 may not be arranged in a plurality of rows but may be arranged in only one row. The plurality of units 240 may not be arranged in a plurality of columns but may be arranged in only one column. The plurality of units 240 may be arranged such that the number of columns is equal to the number of rows. The plurality of protrusions 260 may have a configuration in which pressure is applied to the lithium metal battery 100 as uniformly as possible and is difficult to buckle.

[0025] Thereby, while reducing the weight compared to metal plate restraint etc., when the thickness of the lithium metal battery changes due to charge and discharge, the restraint pressure on the lithium metal battery can be appropriately adjusted. Further, when the unit 240 is manufactured by vulcanizing etc. a rubber material and molding it, it can be manufactured by using a relatively simple shape and a small mold. By arranging and combining the plurality of units 240 manufactured in this way in different orientations, it becomes possible to manufacture a relatively complex rubber-based buffer structure without using a relatively complex and large mold.

[0026] FIG. 4 schematically shows an example of the frame member 230. The dimensions shown in FIG. 4 are for example only, and other dimensions may be used. The frame member 230 has a recess 232. The depth of the recess 232 may be the same as the height of the base 250. The depth of the recess 232 may be from one-tenth to one-half of the height of the base 250. The depth of the recess 232 may be from one-fifth to one-third of the height of the base 250.

[0027] FIG. 5 schematically shows an example of the protrusion 260. Each of the plurality of units 240 may have a planar base 250 and at least one protrusion 260 protruding from the base 250 in the thickness direction of the base 250. For each of the plurality of units 240, the length 266 of the protrusion 260 along the first direction 262 parallel to the plane 252 of the base 250 and the length 268 of the protrusion 260 along the second direction 264 parallel to the plane 252 different from the first direction 262 may be different. When the protrusion 260 is pressed against the lithium metal battery 100, the orientation of at least one protrusion 260 of at least one of the plurality of units 240 is different from the orientation of the other protrusions 260 and contacts the lithium metal battery 100. Thereby, compared with the case where all the protrusions 260 are arranged in the same direction, the protrusions 260 are more resistant to deformation due to falling over. Therefore, it is possible to suppress the sliding of the lithium metal battery 100 within the battery system 10 and stably restrain it.

[0028] In the example shown in FIG. 5, the first direction 262 of the protrusion 260 and the second direction 264 of the protrusion 260 intersect at a right angle. However, as long as they are parallel to the plane 252 of the base 250, the angle formed by the first direction 262 of the protrusion 260 and the second direction 264 of the protrusion 260 may be any degree. For example, the angle formed by the first direction 262 of the protrusion 260 and the second direction 264 of the protrusion 260 may be 30°, 45°, 60°, 120°, 135°, etc.

[0029] In the example shown in FIG. 5, although the shape of the cross section of the protrusion 260 that intersects the thickness direction of the protrusion 260 is rectangular, if the length 266 along the first direction 262 and the length 268 along the second direction 264 are different, the cross-sectional shape may be any shape. For example, the cross-sectional shape is triangular. For example, the cross-sectional shape is a polygon with four or more sides.

[0030] In the example shown in FIG. 5, the first direction of the base 250 and the first direction 262 of the protrusion 260 are the same direction, but it is not limited to this. Also, the second direction of the base 250 and the second direction 264 of the protrusion 260 are the same direction, but it is not limited to this. That is, the angles formed by each of the first direction of the base 250, the second direction of the base 250, the first direction 262 of the protrusion 260, and the second direction 264 of the protrusion 260 are not particularly limited as long as they do not conflict with the above conditions.

[0031] By adjusting the shape and arrangement of the protrusion 260 in this way, the restraining force generated by the unit 240 and the resistance to the toppling of the protrusion 260 can be adjusted. Consequently, when the thickness of the lithium metal battery changes due to charge and discharge, it is possible to suppress the slide within the battery system 10 of the lithium metal battery 100 while appropriately maintaining the restraining pressure on the lithium metal battery.

[0032] FIGS. 6 and 7 schematically show an example of the unit 240. In the example shown in FIGS. 6 and 7, the base 250 is square. Thereby, when the unit 240 is arranged in the frame member 230 without gaps and without intervals, the arrangement of the unit 240 can be facilitated. Also, the packing between adjacent units 240 is improved, the unit 240 is easily fixed within the frame member 230, and the positional deviation of the unit 240 is suppressed. Consequently, the slide within the battery system 10 of the lithium metal battery 100 can be suppressed.

[0033] In FIGS. 6 and 7, an example is shown in which each of the units 240 has nine protrusions 260 arranged in three rows and three columns in the same orientation on a square base 250, but the present invention is not limited thereto. Each of the plurality of units 240 may have a plurality of protrusions 260 arranged in a plurality of rows and a plurality of columns in the same orientation on the square base 250. The number n of the plurality of rows and the number m of the plurality of columns may be any integers. m and n may be different integers from each other, that is, the number of the plurality of rows and the number of the plurality of columns may be different. For example, examples of arranging the plurality of protrusions 260 in 7 rows x 4 columns, 12 rows x 9 columns, etc. can be given. m and n may be integers of the same value, that is, the number of the plurality of rows and the number of the plurality of columns may be equal. For example, examples of arranging the plurality of protrusions 260 in 2 rows x 2 columns, 4 rows x 4 columns, 5 rows x 5 columns, etc. can be given.

[0034] In the example shown in FIGS. 6 and 7, the plurality of protrusions 260 on one unit 240 are all arranged in the same orientation, but among the plurality of units 240, at least one unit 240 is arranged in a different orientation so that the plurality of units 240 are arranged. Therefore, among the plurality of protrusions 260 on the surface constituted by the plurality of units 240, the plurality of protrusions 260 on at least one unit 240 are arranged in a different orientation from the plurality of protrusions 260 on the other remaining units 240. When an external force such that the lithium metal battery 100 slides on the protrusions 260 acts, when the protrusions 260 are all arranged in the same direction, although the protrusions 260 are difficult to fall down with respect to a specific direction, they are easy to fall down with respect to another direction different from that direction. However, as described above, by arranging the directions of the plurality of protrusions 260 to be different, the plurality of protrusions 260 as a whole can be made difficult to fall down in various directions. As a result, the slide of the lithium metal battery 100 in the battery system 10 can be suppressed and stably restrained. In addition, it is possible to manufacture a relatively complex buffer structure using only a small mold with a relatively simple shape without using a large mold with a relatively complex shape.

[0035] Figures 8 and 9 schematically show an example of the unit 240. In the example shown in Figures 8 and 9, the base 250 is a regular hexagon. Figures 8 and 9 show an example in which each of the units 240 has six protrusions 260 arranged in the same orientation on the regular hexagonal base 250, but the number and orientation of the protrusions 260 are not limited to this. The number of the protrusions 260 may be any positive integer, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13. When the unit 240 has a plurality of protrusions 260, the orientations of the plurality of protrusions 260 may be different from each other, or the orientations of some of the plurality of protrusions 260 may be different. When the unit 240 has a plurality of protrusions 260, the orientations of all of the plurality of protrusions 260 may be the same.

[0036] Accordingly, when the units 240 are arranged in the frame member 230 without gaps and without intervals, the arrangement of the units 240 can be facilitated. Further, compared with the case where the base 250 is square, the combination of the directions of the plurality of protrusions 260 increases, so that the slide of the lithium metal battery 100 in the battery system can be suppressed in more directions. Further, the packing between adjacent units 240 is further improved, the unit 240 is more easily fixed in the frame member 230, and the positional deviation of the unit 240 is further suppressed. Consequently, the slide of the lithium metal battery 100 in the battery system 10 can be further suppressed.

[0037] When the unit 240 shown in FIGS. 8 and 9 is fixed inside the frame member 230, the fixing method may be adjusted to correspond to the regular hexagonal base 250 of the unit 240. As an example, the shape of the recess 232 of the frame member 230 is changed to correspond to the regular hexagonal shape of the base 250 of the unit 240. Specifically, as shown in the example of FIG. 9, when a plurality of units 240 are arranged without gaps and at intervals, the shape of the recess 232 of the frame member 230 is made to correspond to the shape along the outer edge of the polygon formed by gathering the plurality of units 240. As another example, without changing the shape of the recess 232 of the frame member 230, an attachment is fixed inside the recess 232. In this case, the outer side wall of the attachment has a shape along the side wall of the recess 232, and the inner side wall of the attachment has a shape along the outer edge of the polygon formed by gathering the plurality of units 240.

[0038] FIG. 10 schematically shows an example of the protrusion 260. In the example shown in FIG. 10, the protrusion 260 has a hollow portion 272 that opens toward the base 250, and the top surface 274 on the side opposite to the base 250 side has a curved shape. The hollow portion 272 may have any shape as long as it is hollow. For example, the hollow portion 272 has a shape substantially similar to the protrusion 260. Thereby, the unit 240 can be made lighter while maintaining the restraining force generated by the protrusion 260 and the resistance to tipping of the protrusion 260 to a certain extent. Further, compared with the case where the hollow portion 272 is not provided, the creep phenomenon under constant strain conditions can be reduced.

[0039] The opening facing the side of the base portion 250 of the hollow portion 272 may penetrate the base portion 250 and open to a plane on the side opposite to the protruding portion 260 of the base portion 250. When the hollow portion 272 penetrates the base portion 250, the cross-sectional area of a cross-section parallel to the plane 252 of the hollow portion 272 may become wider as it approaches the plane on the side opposite to the protruding portion 260 of the base portion 250. Thereby, the unit 240 can be further lightened while maintaining the restraining force generated by the protruding portion 260 and the resistance to falling of the protruding portion 260. In addition, since the core portion corresponding to the hollow portion 272 of the mold easily comes off, it is expected that the manufacturing efficiency during the manufacture of the unit 240 is increased and the yield rate of the unit 240 is increased. The opening facing the side of the base portion 250 of the hollow portion 272 may not penetrate the base portion 250, may not open to the plane on the side opposite to the protruding portion 260 of the base portion 250, and may be closed on the plane on the side of the protruding portion 260 of the base portion 250 or inside the base portion 250. Thereby, in addition to being able to further lighten the unit 240 while maintaining the restraining force generated by the protruding portion 260 and the resistance to falling of the protruding portion 260, the contact area between the unit 240 and the frame member 230 can be ensured, so that the unit 240 is less likely to slip within the frame member 230, and the displacement of the unit 240 is suppressed. Consequently, the slide within the battery system 10 of the lithium metal battery 100 can be suppressed.

[0040] Each of the above embodiments may be realized in combination as long as there is no contradiction. For example, it is a case where the plurality of protruding portions 260 of the unit 240 shown in FIG. 3 are the protruding portions 260 having the hollow portion 272 shown in FIG. 10. For example, it is a case where the plurality of protruding portions 260 of the unit 240 shown in FIGS. 6, 7, 8, and 9 are the protruding portions 260 having the hollow portion 272 shown in FIG. 10.

[0041] FIG. 11 schematically shows an example of the battery system 10. In the example shown in FIG. 11, instead of the plurality of units 240, a plate-like member 280 is disposed inside the frame member 230. The plate-like member 280 has a plurality of plate-like base portions 250 and a plurality of protruding portions 260 on the base portions 250. Except that the plate-like member 280 is disposed inside the frame member 230, the structure of the battery system 10 shown in FIG. 11 may be common to the battery system 10 shown in FIGS. 1 and 2. The description thereof is omitted.

[0042] FIG. 12 schematically shows an example of the plate-like member 280. At least any one of the plurality of protrusions 260 of the plate-like member 280 has a hole 276 in the top surface 274 that is pressed against the lithium metal battery 100. In the example shown in FIG. 12, an example in which the protrusions 260 are arranged in 5 rows × 4 columns is shown, but the arrangement of the protrusions 260 is not limited to this, as in the previous example. In the example shown in FIG. 12, for all 20 protrusions 260, the holes 276 having a circular cross-section are each arranged at the center of the top surface 274 of the protrusion 260, but the number of protrusions 260 having the hole 276, the cross-sectional shape of the hole 276, the number and arrangement of the holes 276 are not limited to this. The position of the hole 276 within the top surface 274 of the protrusion 260 and the number of holes 276 per protrusion 260 are not limited to this. Among the plurality of protrusions 260, all the protrusions 260 may have the hole 276, some of the protrusions 260 may have the hole 276, or only one protrusion 260 may have the hole 276. The cross-sectional shape of the hole 276 does not have to be circular, and may be any cross-sectional shape such as triangular, quadrangular, polygonal, elliptical, etc. The number of holes 276 per protrusion 260 may be plural. The number of holes 276 per protrusion 260 may be one. The position of the hole 276 within the top surface 274 of the protrusion 260 may be any position. When the number of holes 276 per protrusion 260 is one, the position of the hole 276 within the top surface 274 of the protrusion 260 may be the center of the top surface 274 of the protrusion 260. When the number of holes 276 per protrusion 260 is one, the position of the hole 276 within the top surface 274 of the protrusion 260 may be other positions other than the center within the top surface 274 of the protrusion 260.

[0043] As shown in FIG. 12, the hole portion 276 has a hole shape and does not have a shape like a groove that penetrates between side walls of any of the protrusion portions 260. By providing the hole portion 276 instead of a groove in the protrusion portion 260, the portions around the hole portion 276 can support each other, so that the rigidity of the protrusion portion 260 can be maintained higher compared with the case where a groove is provided, and the protrusion portion 260 is less likely to fall. The material of the plate-like member 280 may be the same as the material of the unit 240. Description thereof is omitted.

[0044] FIG. 13 schematically shows an example of the protrusion portion 260 of the plate-like member 280. The depth of the hole portion 276 is not particularly limited. Specifically, the hole portion 276 may extend from the top surface 274 to any depth inside the protrusion portion 260. The hole portion 276 may extend from the top surface 274 to the surface of the base portion 250 on the protrusion portion 260 side. The hole portion 276 may extend from the top surface 274 to any depth inside the base portion 250. The hole portion 276 may penetrate the base portion 250 and extend from the top surface 274 to the surface of the base portion 250 on the side opposite to the protrusion portion 260. Thus, by adjusting the cross-sectional shape, number, arrangement, depth, etc. of the hole portion 276, the restraining force generated by the protrusion portion 260 and the ease of falling of the protrusion portion 260 can be adjusted, and by extension, the restraining conditions by the restraint 200 of the lithium metal battery 100 can be adjusted to desired conditions.

[0045] FIG. 14 schematically shows an example of the protrusion 260 of the plate-like member 280. In the example shown in FIG. 14, the cross-sectional area of the protrusion 260 increases from the top surface 274 toward the base 250. In other words, the two opposing side surfaces of the protrusion 260 are tapered so that the distance between them widens downward. In the example shown in FIG. 14, it is monotonically tapered, but the side surfaces of the protrusion 260 may be curved surfaces instead of flat surfaces. The side surfaces of the protrusion 260 may be a plurality of planes angled with respect to each other. In the example shown in FIG. 14, the cross-sectional area of the hole portion 276 increases as it approaches the plane on the opposite side of the protrusion 260 from the top surface 274 to the base 250. Thereby, while maintaining the restraining force generated by the protrusion 260 and the resistance to tipping of the protrusion 260, the plate-like member 280 can be made lighter. In addition, since the core portion corresponding to 276 of the mold is likely to come out, it is expected that the manufacturing efficiency during the manufacture of the unit 240 will increase and the yield rate of the unit 240 will increase.

[0046] FIG. 15 schematically shows an example of the HAPS700 equipped with the battery system 10. The HAPS700 is an aircraft that provides a wireless communication service to the user terminal 30 within the communication area 704 formed by irradiating the beam 702 toward the ground. The HAPS700 may be an example of an aircraft including the battery system 10 and a propulsion force generating device that generates a propulsion force using the electrical energy stored in the battery system 10.

[0047] The HAPS700 includes a fuselage 710, a central portion 720, a propeller 730, a pod 740, and a solar cell panel 750. The fuselage 710 has wing portions 712. The wing portions 712 include a left wing portion 714 and a right wing portion 716.

[0048] For example, the battery system 10 is disposed inside the wing portion 712. The electrical energy stored in the battery system 10 is utilized by each component provided in the HAPS 700. For example, the electrical energy stored in the battery system 10 is utilized by the motor of the propeller 730 that generates thrust. As a specific example, a plurality of battery systems 10 connected in parallel are disposed inside the wing portion 712. Among the plurality of battery systems 10, the plurality of battery systems 10 on the left side may be disposed in the left wing portion 714, and the plurality of battery systems 10 on the right side may be disposed in the right wing portion 716. The power discharged by the plurality of battery systems 10 is utilized by each component provided in the HAPS 700. For example, the power discharged by the plurality of battery systems 10 is utilized by the motor of the propeller 730.

[0049] Inside the central portion 720, a flight control unit 722 and a communication control unit 724 are disposed. The flight control unit 722 controls the flight of the HAPS 700 using the power discharged by the plurality of battery systems 10. The communication control unit 724 controls the communication of the HAPS 700 using the power discharged by the plurality of battery systems 10.

[0050] The flight control unit 722 controls the flight of the HAPS 700, for example, by controlling the rotation of the propeller 730. Also, the flight control unit 722 may control the flight of the HAPS 700 by changing the angles of flaps and elevators (not shown). The flight control unit 722 may include various sensors such as a positioning sensor such as a GPS sensor, a gyro sensor, and an acceleration sensor to manage the position, movement direction, and movement speed of the HAPS 700.

[0051] The communication control unit 724 forms a communication area 704 on the ground using an SL (Service Link) antenna. The communication control unit 724 forms a service link with the ground user terminal 30 using the SL antenna. The SL antenna may be a multi-beam antenna. The communication area 704 may be a multi-cell.

[0052] The communication control unit 724 may form a feeder link with the ground gateway 40 using the FL (Feeder Link) antenna. The communication control unit 724 may access the network 20 via the gateway 40.

[0053] The communication control unit 724 may communicate with the communication satellite 50 using the satellite communication antenna. The communication control unit 724 may access the network 20 via the communication satellite 50 and the satellite communication station 60.

[0054] The user terminal 30 may be any communication terminal as long as it can communicate with the HAPS 700. For example, the user terminal 30 is a mobile phone such as a smartphone. The user terminal 30 may be a tablet terminal or a PC (Personal Computer), etc. The user terminal 30 may be a so-called IoT (Internet of Thing) device. The user terminal 30 may include anything corresponding to the so-called IoE (Internet of Everything).

[0055] The HAPS 700 relays the communication between the network 20 and the user terminal 30, for example, via the feeder link or the communication satellite 50 and the service link. The HAPS 700 may provide a wireless communication service to the user terminal 30 by relaying the communication between the user terminal 30 and the network 20.

[0056] The network 20 includes a mobile communication network. The mobile communication network may comply with any of the LTE (Long Term Evolution) communication method, 5G (5th Generation) communication method, 3G (3rd Generation) communication method, and communication methods after the 6G (6th Generation) communication method. The network 20 may include the Internet.

[0057] HAPS700 transmits data received from user terminal 30 within communication area 704 to network 20, for example. Also, when HAPS700 receives data destined for user terminal 30 within communication area 704 via network 20, for example, it transmits such data to user terminal 30.

[0058] HAPS700 maintains communication area 704 over a specific area on the ground while orbiting a predetermined flight path in the stratosphere, for example. HAPS700 stores the power generated by solar panel 750 during the day in a plurality of battery systems 10 and maintains flight in the stratosphere by using the power of the plurality of battery systems 10 at night. HAPS700, for example, stores potential energy by ascending while charging a plurality of battery systems 10 during the day, and maintains flight in the stratosphere by gently descending at night and operating propeller 730 and the like using the power of battery system 10 as appropriate.

[0059] Management device 800 manages a plurality of HAPS700s. Management device 800 may communicate with HAPS700 via network 20 and gateway 40. Management device 800 may also communicate with HAPS700 via network 20, satellite communication station 60, and communication satellite 50.

[0060] Management device 800 controls HAPS700 by transmitting an instruction. Management device 800 may cause HAPS700 to circle over the target area so that communication area 704 covers the target area on the ground. HAPS700, for example, maintains a feeder link with gateway 40 by adjusting the pointing direction of the FL antenna while flying in a circular orbit over the target area, and maintains coverage of the target area by communication area 704 by adjusting the pointing direction of the SL antenna.

[0061] As described above, the present invention has been described using embodiments. However, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. It is clear from the description of the claims that forms with such changes or improvements can also be included in the technical scope of the present invention.

[0062] It should be noted that the execution order of each process such as operations, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, the specification, and the drawings is not explicitly stated as "before" or "preceding" etc., and can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flows in the claims, the specification, and the drawings, even if they are described using "first," "next," etc. for convenience, it does not mean that it is essential to implement them in this order.

Explanation of Reference Numerals

[0063] 10 Battery system, 20 Network, 30 User terminal, 40 Gateway, 50 Communication satellite, 60 Satellite communication station, 100 Lithium metal battery, 110 Battery cell, 200 Restraint, 210 Fixed member, 220 Restraint member, 230 Frame member, 232 Depression, 240 Unit, 250 Base, 252 Plane, 260 Protrusion, 262 First direction, 264 Second direction, 266 Length, 268 Length, 272 Hollow part, 274 Top surface, 276 Hole part, 280 Plate-like member, 700 HAPS, 702 Beam, 704 Communication area, 710 Airframe, 712 Wing part, 714 Left wing part, 716 Right wing part, 720 Central part, 722 Flight control part, 724 Communication control part, 730 Propeller, 740 Pod, 750 Solar panel, 800 Management device

Claims

1. A restraint for restraining a lithium metal battery including a plurality of battery cells, comprising: a frame member; a plurality of units made of a rubber-based material and disposed inside the frame member, each of the plurality of units including at least one protrusion, and at least one of the plurality of units being disposed in a different orientation from other units; a restraint member having the same; a fixing member for fixing the plurality of units in a state of being pressed against the lithium metal battery; and a restraint including the same.

2. Each of the plurality of units has a planar base portion and the at least one protrusion protruding from the base portion in the thickness direction of the base portion, The restraint according to claim 1, wherein a length of the protrusion along a first direction parallel to the plane of the base portion and a length along a second direction parallel to the plane different from the first direction are different.

3. The restraint according to claim 2, wherein the base portion is square.

4. The restraint according to claim 3, wherein each of the plurality of units has a plurality of protrusions arranged in the same orientation in a plurality of rows and a plurality of columns on the square base portion.

5. The restraint according to claim 2, wherein the base portion is regular hexagon.

6. The restraint according to any one of claims 2 to 5, wherein the protrusion has a hollow portion opening toward the side of the base portion, and a top surface opposite to the side of the base portion has a curved shape.

7. A restraint for restraining a lithium metal battery including a plurality of battery cells, comprising: a plate-like member made of a rubber-based material and having a plate-like base portion and a plurality of protrusions on the base portion; a frame member into which the plate-like member is fitted; a restraint member having the same; a fixing member for fixing the plurality of protrusions of the plate-like member fitted into the frame member in a state of being pressed against the lithium metal battery; and including the same, The restraint, wherein at least one of the plurality of protrusions has a hole portion on a top surface pressed against the lithium metal battery.

8. The restraint according to claim 7, wherein at least one of the plurality of protrusions has the hole portion at the center of the top surface.

9. The restraint according to claim 7 or 8, wherein the plurality of protrusions have the hole portion on the top surface.

10. A battery system including the restraint according to any one of claims 1 to 5, 7, and 8; and the lithium metal battery.

11. The battery system according to claim 10; ​ A propulsion device that generates propulsion force by using the electrical energy stored in the battery system, A flying object comprising the same.

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