Restraint, battery system, and aircraft

Abstract

The present invention provides a restraint for restraining a lithium metal battery which includes a plurality of battery cells, said restraint comprising: a restraining member that has a frame member and a plurality of units which are made of a rubbery material, and which are disposed inward of the frame member, the plurality of units each including at least one protrusion, and at least one unit among the plurality of units of being disposed in a different orientation from other units; and a fixing member that fixes the plurality of units in a state in which pressure is applied with the plurality of units being pressed against the lithium metal battery. The plurality of units each have a planar base part and at least one protrusion which protrudes from the base part in the thickness direction of the base part. The length of the protrusion along a first direction which is parallel to the plane of the base part differs from the length of the protrusion along a second direction which differs from the first direction and which is parallel to the plane.

Description

Restraint, battery system, and flying vehicle

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

[0002] Patent Document 1 describes a lithium-ion battery in which a plurality of stacked battery cells are sandwiched between metal plates and constrained using metal bands, thereby applying constraining pressure to the battery cells in the stacking direction. [Prior Art Documents] [Patent Documents] [Patent Document 1] JP 2022-075152 A General disclosure

[0003] (Means for Solving the Problem) According to one embodiment of the present invention, a restraint is provided. The restraint may restrain a lithium metal battery including a plurality of battery cells. The restraint may include a frame member. The restraint may include a restraining member made of a rubber-based material and having a plurality of units arranged 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 different orientation from the other units. The restraint may include a fixing member that presses the plurality of units against the lithium metal battery and fixes them in a pressurized state. The restraint may restrain the lithium metal battery along the direction in which the plurality of battery cells are arranged.

[0004] In the restraint device, each of the multiple units may have a planar base. Each of the multiple units may have the at least one protrusion protruding from the base in a thickness direction of the base. The length of the protrusion along a first direction parallel to the plane of the base may differ from the length along a second direction parallel to the plane different from the first direction. The base may be square. Each of the multiple units may have multiple protrusions arranged in multiple rows and multiple columns in the same direction on the square base. The base may be hexagonal. In any of the restraint devices, the multiple units may be arranged side by side so as to be in contact with each other. In any of the restraint devices, the multiple units may be arranged at intervals from each other.

[0005] In any of the above restraints, the protrusion may have a hollow portion that opens toward the base. The protrusion may have a curved top surface opposite the base. In any of the above restraints, the frame member may have a recess. In any of the above restraints, the shape of the recess may correspond to the shape of the base. In any of the above restraints, the shape of the recess may correspond to the outer edge of the overall shape formed by the multiple units together when the multiple units are arranged without any gaps. In any of the above restraints, the restraining member may have an attachment that is fixed inside the recess. In the above restraint, the outer sidewall of the attachment may have a shape that corresponds to the sidewall of the recess, and the inner sidewall of the attachment may have a shape that corresponds to the outer edge of the overall shape formed by the multiple units together. In any of the above restraints, the at least one protrusion may have a hole in its top surface that is pressed against the lithium metal battery.

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

[0007] In any of the restraint devices described above, at least one of the plurality of protrusions may have the hole at the center of the top surface. In any of the restraint devices described above, the plurality of protrusions may have the hole at the top surface.

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

[0009] The above summary of the invention does not list all of the necessary features of the present invention, and subcombinations of these features may also constitute inventions.

[0010] 1 shows an example of a battery system 10. 1 shows an example of a battery system 10. 1 shows an example of a unit 240. 1 shows an example of a frame member 230. 1 shows an example of a protrusion 260. 1 shows an example of a unit 240. 1 shows an example of a plurality of units 240. 1 shows an example of a unit 240. 1 shows an example of a plurality of units 240. 1 shows an example of a protrusion 260. 1 shows an example of a battery system 10. 1 shows an example of a plate-shaped member 280. 1 shows an example of a protrusion 260. 1 shows an example of a protrusion 260. 1 shows an example of a HAPS 700 equipped with the battery system 10.

[0011] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention as claimed. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0012] Lithium-ion batteries can achieve sufficient battery performance by restraining them with no or low pressure, approximately 0.0 to 0.2 MPa. On the other hand, it has been discovered that restraining lithium metal batteries with the same pressure as lithium-ion batteries results in poor cycle life. Increasing the restraining pressure using methods such as metal plate restraint improves cycle life, but the restraining member becomes heavier, resulting in a decrease in weight energy density. Furthermore, lithium metal batteries change in thickness with charging and discharging. Metal plate restraints do not properly adjust the pressure, which can result in excessive or insufficient restraining pressure on the lithium metal battery. It is also important to suppress sliding of the lithium metal battery and ensure stable restraint even if the lithium metal battery's thickness changes. The restraining device 200 according to this embodiment is lighter in weight than metal plate restraints and has a structure that appropriately adjusts the restraining pressure on the lithium metal battery when the lithium metal battery's thickness changes during charging and discharging. It also has a structure that appropriately suppresses sliding of the lithium metal battery 100.

[0013] 1 and 2 schematically show an example of a battery system 10. The battery system 10 includes a lithium metal battery 100 and a restraint device 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 device 200 restrains the lithium metal battery 100. The restraint device 200 may restrain the lithium metal battery 100 along the direction in which the plurality of battery cells 110 are arranged.

[0015] 1 and 2, the restraining device 200 has a fixing member 210 and a restraining member 220. The fixing member 210 clamps the lithium metal battery 100 with the restraining member 220 and applies pressure to fix the lithium metal battery 100.

[0016] In the example shown in FIGS. 1 and 2 , the restraining device 200 has restraining members 220 on both left and right sides of the lithium metal battery 100. The restraining device 200 may have restraining members 220 on only one side of the lithium metal battery 100, rather than on both left and right sides of the lithium metal battery 100. In this case, for example, a member made of a material with relatively high hardness and relatively light weight, such as carbon fiber composite material (CFRP: Carbon Fiber Reinforced Plastics), is disposed on the side of the lithium metal battery 100 opposite the side on which the restraining member 220 is disposed. The fixing member 210 then presses the restraining member 220 against the lithium metal battery 100 to fix it in a pressurized state. The fixing member 210 may clamp the lithium metal battery 100 between the restraining member 220 and a member disposed on the side on which the restraining member 220 is disposed on the lithium metal battery 100, thereby fixing it in a pressurized state.

[0017] In this embodiment, a case where the restraint device 200 is provided with restraint members 220 on both the left and right sides of the lithium metal battery 100 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. While FIG. 2 illustrates an example in which the restraining member 220 has two vertical rows of units 240, the number and arrangement of the units 240 are not limited to this. For example, the restraining member 220 may have three or more rows of units 240. Similarly, the restraining member 220 may have multiple horizontal columns of units 240. The restraining member 220 may have one row and multiple columns of units 240, or multiple rows and one column of units 240. The plurality of units 240 may be arranged side by side so as to be in contact with each other. This allows the plurality of units 240 to be fixed within the frame member 230 without misalignment, contributing to stably restraining the lithium metal battery 100 within the battery system 10.

[0019] The multiple units 240 may be fixed inside the frame member 230. For example, the multiple units 240 are fixed by adhering them to the inside of the frame member 230 with an adhesive or the like. For example, recesses or the like are provided on the side of the multiple units 240 that contacts the frame member 230, and convex portions or the like of corresponding shapes are provided at corresponding positions on the side of the frame member 230 that contacts the multiple units 240, and the multiple units 240 are fixed by fitting the convex portions or the like into the recesses or the like. This allows the multiple units 240 to be fixed inside the frame member 230 without shifting, contributing to stably restraining the lithium metal batteries 100 within the battery system 10.

[0020] When multiple units 240 are fixed inside the frame member 230, the multiple units 240 may be arranged at intervals from one another inside the frame member 230. In this case, the intervals between the multiple units 240 may be uniform. This allows the multiple units 240 to be fixed without misalignment within the frame member 230, contributing to stably restraining the lithium metal batteries 100 within the battery system 10, while also reducing the weight of the entire battery system 10 and improving the weight-energy density by the amount of the multiple units 240 arranged at intervals. In the following embodiments, a case will be mainly described in which the units 240 are arranged side by side so as to be in contact with one another without any intervals.

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

[0022] The multiple units 240 can be manufactured by molding a rubber-based material using various methods. The molding method for the rubber-based material may be appropriately selected depending on the type of material, desired physical properties, required production capacity, etc., and is not particularly limited. Specific examples include direct pressure molding using a mold, injection molding, injection molding, extrusion molding, etc. As another specific example, molding may be performed by 3D printing of a thermoplastic elastomer or the like without using a mold. A plate-shaped rubber may be cut with a blade, laser, or the like to form the desired shape. The restraint 200 can be manufactured by manufacturing multiple units 240 using these molding methods and arranging them in the frame member 230.

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

[0024] FIG. 3 schematically illustrates an example of a unit 240. Each of the multiple units 240 includes at least one protrusion 260. While FIG. 3 illustrates an example in which the unit 240 includes a total of nine protrusions 260 arranged in three rows and three columns, the arrangement and number of the protrusions 260 are not limited to this. Each of the multiple units 240 may include one protrusion 260. Each of the multiple units 240 may include two, three, four, five, six, seven, or eight protrusions 260. Each of the multiple units 240 may include ten or more protrusions 260. The multiple units 240 may be arranged in any arrangement that can appropriately adjust the restraining pressure on the lithium metal battery 100, suppress sliding of the lithium metal battery 100 within the battery system 10, and stably restrain the lithium metal battery 100. The multiple units 240 may be arranged in multiple rows and / or multiple columns. The multiple units 240 may also be arranged in only one row, rather than multiple rows. The multiple units 240 may be arranged in only one column instead of multiple columns. The multiple units 240 may be arranged so that the number of columns and the number of rows are equal. The multiple protrusions 260 may have a configuration that applies pressure to the lithium metal battery 100 as uniformly as possible and is less likely to buckle.

[0025] This reduces weight compared to metal plate restraints, and allows for appropriate adjustment of the restraining pressure on the lithium metal battery when the thickness of the lithium metal battery changes due to charging and discharging. Furthermore, when manufacturing the unit 240 by molding a rubber material through vulcanization or the like, it can be manufactured using a relatively simple and small mold. By arranging and combining multiple units 240 manufactured in this manner in different orientations, it becomes possible to manufacture a relatively complex rubber-based buffer structure without using a relatively complex and large mold.

[0026] Figure 4 schematically shows an example of the frame member 230. The dimensions shown in Figure 4 are merely an example, 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 one-tenth to one-half the height of the base 250. The depth of the recess 232 may be one-fifth to one-third the height of the base 250.

[0027] FIG. 5 schematically illustrates an example of a protrusion 260. Each of the multiple 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 multiple units 240, the protrusion 260 may have a length 266 along a first direction 262 parallel to the plane 252 of the base 250 and a length 268 along a second direction 264 parallel to the plane 252, different from the first direction 262. When the protrusion 260 is pressed against the lithium metal battery 100, the orientation of at least one of the multiple units 240's protrusion 260 contacts the lithium metal battery 100 in a different orientation from the other protrusions 260. This makes the protrusion 260 more resistant to deformation due to tipping over than when all the protrusions 260 are arranged in the same direction. Therefore, the lithium metal battery 100 can be prevented from sliding within the battery system 10 and can be stably restrained.

[0028] 5, the first direction 262 of the protrusion 260 and the second direction 264 of the protrusion 260 intersect at a right angle, but the angle formed by the first direction 262 of the protrusion 260 and the second direction 264 of the protrusion 260 may be any angle as long as they are parallel to the plane 252 of the base 250. 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] 5, the cross-sectional shape of the protrusion 260 intersecting the thickness direction of the protrusion 260 is rectangular, but the cross-sectional shape may be any shape as long as the length 266 along the first direction 262 and the length 268 along the second direction 264 are different. For example, the cross-sectional shape is a triangle. For example, the cross-sectional shape is a polygon with more sides than a square.

[0030] 5 , the first direction of the base 250 and the first direction 262 of the protrusion 260 are the same direction, but this 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 this is not limited to this. In other words, the angles formed by 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 contradict the above conditions.

[0031] By adjusting the shape and arrangement of protrusion 260 in this way, it is possible to adjust the restraining force generated by unit 240 and the resistance to tipping of protrusion 260. Furthermore, even if the thickness of the lithium metal battery changes due to charging and discharging, it is possible to prevent lithium metal battery 100 from sliding within battery system 10 while maintaining an appropriate restraining pressure on the lithium metal battery.

[0032] 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. This makes it easier to arrange the units 240 when arranging the units 240 without gaps between them within the frame member 230. Furthermore, this improves the packing between adjacent units 240, making it easier for the units 240 to be fixed within the frame member 230 and reducing misalignment of the units 240. This in turn reduces sliding of the lithium metal battery 100 within the battery system 10.

[0033] 6 and 7 show an example in which each unit 240 has nine protrusions 260 arranged in three rows and three columns in the same direction on a square base 250, but this is not limiting. Each of the multiple units 240 may have multiple protrusions 260 arranged in multiple rows and multiple columns in the same direction on the square base 250. The number of rows n and the number of columns m may be any integer. m and n may be different integers, i.e., the numbers of rows and columns may be different. For example, the multiple protrusions 260 may be arranged in 7 rows x 4 columns, 12 rows x 9 columns, etc. m and n may be the same integer, i.e., the numbers of rows and columns may be equal. For example, the multiple protrusions 260 may be arranged in 2 rows x 2 columns, 4 rows x 4 columns, 5 rows x 5 columns, etc.

[0034] In the examples shown in Figures 6 and 7, all of the protrusions 260 on one unit 240 are oriented in the same direction, but the multiple units 240 are arranged so that at least one of the multiple units 240 is oriented in a different direction. Therefore, among the multiple protrusions 260 on a surface formed by the multiple units 240, the multiple protrusions 260 on at least one unit 240 are oriented in a different direction from the multiple protrusions 260 on the remaining units 240. When an external force acts on the lithium metal battery 100 such that it slides on the protrusions 260, if all of the protrusions 260 are oriented in the same direction, the protrusions 260 are unlikely to tip in a specific direction but are likely to tip in other directions. However, as described above, by arranging the multiple protrusions 260 so that they are oriented in different directions, the multiple protrusions 260 as a whole can be made less likely to tip in various directions. As a result, sliding of the lithium metal battery 100 within the battery system 10 is suppressed, and the lithium metal battery 100 can be stably restrained. Furthermore, 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] 8 and 9 schematically illustrate an example of a unit 240. In the example illustrated in FIGS. 8 and 9, the base 250 is a regular hexagon. While FIGS. 8 and 9 illustrate an example in which each unit 240 has six protrusions 260 arranged in the same orientation on the regular hexagonal base 250, the number and orientations of the protrusions 260 are not limited to this. The number of protrusions 260 may be any positive integer, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13. When the unit 240 has multiple protrusions 260, the orientations of the multiple protrusions 260 may be different from each other, or some of the multiple protrusions 260 may be oriented in different directions. When the unit 240 has multiple protrusions 260, the orientations of the multiple protrusions 260 may all be the same.

[0036] This makes it easier to arrange the units 240 without gaps between them within the frame member 230. Furthermore, compared to when the base 250 is square, the number of possible orientation combinations for the multiple protrusions 260 increases, making it possible to prevent the lithium metal battery 100 from sliding within the battery system in more directions. Furthermore, the packing between adjacent units 240 is improved, making it easier for the units 240 to be fixed within the frame member 230, and further preventing the units 240 from shifting out of position. Consequently, sliding of the lithium metal battery 100 within the battery system 10 can be further prevented.

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

[0038] FIG. 10 schematically illustrates an example of the protrusion 260. In the example illustrated in FIG. 10, the protrusion 260 has a hollow portion 272 that opens toward the base 250, and a top surface 274 on the opposite side from the base 250 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 that is approximately similar to that of the protrusion 260. This allows the unit 240 to be made lighter while maintaining a certain level of the restraining force generated by the protrusion 260 and the resistance to tipping of the protrusion 260. Furthermore, creep under constant strain conditions can be reduced compared to when the hollow portion 272 is not provided.

[0039] The opening of hollow portion 272 facing the base 250 may penetrate base 250 and open to a plane of base 250 opposite protrusion 260. When hollow portion 272 penetrates base 250, the cross-sectional area of ​​the cross section of hollow portion 272 parallel to plane 252 may become wider as it approaches the plane of base 250 opposite protrusion 260. This allows unit 240 to be made lighter while maintaining the binding force generated by protrusion 260 and the resistance of protrusion 260 to tipping. Furthermore, since the core portion corresponding to hollow portion 272 of the mold can be easily removed, it is expected that the manufacturing efficiency of unit 240 will be improved and the yield rate of unit 240 will be increased. The opening of hollow portion 272 facing the base 250 side may not penetrate base 250, may not open to the plane of base 250 opposite protrusion 260, and may be closed on the plane of base 250 on the protrusion 260 side or inside base 250. This makes it possible to further reduce the weight of unit 240 while maintaining the binding force generated by protrusion 260 and the resistance of protrusion 260 to tipping over. In addition, since the contact area between unit 240 and frame member 230 can be ensured, unit 240 is less likely to slide within frame member 230, and misalignment of unit 240 is suppressed. This in turn makes it possible to suppress sliding of lithium metal battery 100 within battery system 10.

[0040] The above embodiments may be combined as long as no contradictions exist. For example, the plurality of protrusions 260 of the unit 240 shown in Fig. 3 may be the protrusions 260 having the hollow portions 272 shown in Fig. 10. For example, the plurality of protrusions 260 of the unit 240 shown in Figs. 6, 7, 8, and 9 may be the protrusions 260 having the hollow portions 272 shown in Fig. 10.

[0041] Fig. 11 schematically shows an example of a battery system 10. In the example shown in Fig. 11, a plate-shaped member 280 is arranged inside a frame member 230 instead of a plurality of units 240. The plate-shaped member 280 has a plurality of plate-shaped bases 250 and a plurality of protrusions 260 on the bases 250. Except for the fact that the plate-shaped member 280 is arranged inside the frame member 230, the structure of the battery system 10 shown in Fig. 11 may be the same as that of the battery system 10 shown in Figs. 1 and 2. A description thereof will be omitted.

[0042] FIG. 12 schematically illustrates an example of a plate-shaped member 280. At least one of the multiple protrusions 260 of the plate-shaped member 280 has a hole 276 in a top surface 274 that is pressed against the lithium metal battery 100. In the example illustrated in FIG. 12, the protrusions 260 are arranged in 5 rows and 4 columns, but as with the previous example, the arrangement of the protrusions 260 is not limited to this. In the example illustrated in FIG. 12, a hole 276 with a circular cross section is arranged in the center of each of the 20 protrusions 260's top surface 274. However, the number of protrusions 260 having a hole 276, the cross-sectional shape of the hole 276, and the number and arrangement of the holes 276 are not limited to this. The positions of the holes 276 within the top surface 274 of the protrusions 260 and the number of holes 276 per protrusion 260 are not limited to this. Of the multiple protrusions 260, all of the protrusions 260 may have holes 276, some of the protrusions 260 may have holes 276, or only one of the protrusions 260 may have a 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, rectangular, polygonal, or elliptical. There may be multiple holes 276 per protrusion 260. There may be only one hole 276 per protrusion 260. The position of the hole 276 in the top surface 274 of the protrusion 260 may be any position. When there is only one hole 276 per protrusion 260, the position of the hole 276 in the top surface 274 of the protrusion 260 may be the center of the top surface 274 of the protrusion 260. When there is one hole 276 per protrusion 260 , the position of the hole 276 in the top surface 274 of the protrusion 260 may be at a position other than the center of the top surface 274 of the protrusion 260 .

[0043] 12, the hole 276 is hole-shaped and does not have a groove-like shape that penetrates both side walls of the protrusion 260. By providing the hole 276 instead of a groove in the protrusion 260, the parts around the hole 276 can support each other, so that the rigidity of the protrusion 260 can be maintained at a high level compared to when a groove is provided, and the protrusion 260 is less likely to tip over. The material of the plate-like member 280 may be the same as the material of the unit 240. Explanation will be omitted.

[0044] FIG. 13 schematically illustrates an example of the protrusion 260 of the plate-like member 280. The depth of the hole 276 is not particularly limited. Specifically, the hole 276 may extend from the top surface 274 to any depth within the protrusion 260. The hole 276 may extend from the top surface 274 to the surface of the base 250 facing the protrusion 260. The hole 276 may extend from the top surface 274 to any depth within the base 250. The hole 276 may penetrate the base 250 and extend from the top surface 274 to the surface of the base 250 opposite the protrusion 260. In this way, by adjusting the cross-sectional shape, number, arrangement, depth, etc. of the hole 276, the restraining force generated by the protrusion 260 and the tendency of the protrusion 260 to collapse can be adjusted, and ultimately, the restraining conditions of the lithium metal battery 100 by the restraining device 200 can be adjusted to desired conditions.

[0045] FIG. 14 schematically illustrates an example of the protrusion 260 of the plate-shaped member 280. In the example illustrated 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 increases downward. In the example illustrated in FIG. 14 , the side surfaces of the protrusion 260 are monotonically tapered, but they may not be flat, but may instead be curved. The side surfaces of the protrusion 260 may also be multiple flat surfaces that are angled relative to one another. In the example illustrated in FIG. 14 , the cross-sectional area of ​​the hole 276 increases from the top surface 274 toward the flat surface of the base 250 opposite the protrusion 260. This allows the plate-shaped member 280 to be lighter while maintaining the binding force generated by the protrusion 260 and the resistance of the protrusion 260 to tipping over. Furthermore, since the core portion of the mold corresponding to 276 can be easily removed, it is expected that the manufacturing efficiency of the unit 240 will be improved and the yield of the unit 240 will be increased.

[0046] 15 schematically shows an example of a HAPS 700 equipped with a battery system 10. The HAPS 700 is an air vehicle that provides wireless communication services to user terminals 30 within a communication area 704 formed by irradiating a beam 702 toward the ground. The HAPS 700 may be an example of an air vehicle that includes the battery system 10 and a thrust generating device that generates thrust using electrical energy stored in the battery system 10.

[0047] HAPS 700 includes a fuselage 710, a center section 720, propellers 730, pods 740, and solar panels 750. The fuselage 710 has wing sections 712. The wing sections 712 include a left wing section 714 and a right wing section 716.

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

[0049] A flight control unit 722 and a communication control unit 724 are disposed within the central unit 720. The flight control unit 722 controls the flight of the HAPS 700 using power discharged by the multiple battery systems 10. The communication control unit 724 controls the communication of the HAPS 700 using power discharged by the multiple 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. The flight control unit 722 may also control the flight of the HAPS 700 by changing the angles of flaps or 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, and may 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 a service link (SL) antenna. The communication control unit 724 forms a service link with a terrestrial 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 use a FL (Feeder Link) antenna to form a feeder link with the terrestrial gateway 40. The communication control unit 724 may access the network 20 via the gateway 40.

[0053] The communication control unit 724 may use a satellite communication antenna to communicate with the communication satellite 50. 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 capable of communicating with the HAPS 700. For example, the user terminal 30 may be a mobile phone such as a smartphone. The user terminal 30 may also be a tablet terminal, a PC (Personal Computer), or the like. The user terminal 30 may also be a so-called Internet of Things (IoT) device. The user terminal 30 may include anything that falls under the so-called Internet of Everything (IoE).

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

[0056] The network 20 includes a mobile communication network. The mobile communication network may conform to any of the following communication methods: Long Term Evolution (LTE), 5th Generation (5G), 3rd Generation (3G), and 6th Generation (6G) or later. The network 20 may include the Internet.

[0057] For example, the HAPS 700 transmits data received from a user terminal 30 within the communication area 704 to the network 20. Furthermore, when the HAPS 700 receives data addressed to a user terminal 30 within the communication area 704 via the network 20, the HAPS 700 transmits the data to the user terminal 30.

[0058] HAPS 700 maintains a communication area 704 in a specific area on the ground while circulating along a predetermined flight path in the stratosphere, for example. HAPS 700 stores power generated by solar panels 750 in multiple battery systems 10 during the day and maintains stratospheric flight at night by using the power of multiple battery systems 10. HAPS 700 ascends and stores potential energy while charging multiple battery systems 10 during the day, and maintains stratospheric flight at night by gently descending and appropriately operating propellers 730 and the like using the power of the battery systems 10.

[0059] The management device 800 manages a plurality of HAPSs 700. The management device 800 may communicate with the HAPSs 700 via the network 20 and the gateway 40. The management device 800 may communicate with the HAPSs 700 via the network 20, the satellite communication station 60, and the communication satellite 50.

[0060] The management device 800 controls the HAPS 700 by transmitting instructions. The management device 800 may cause the HAPS 700 to circle above a target area on the ground so that the target area is covered by the communication area 704. For example, while flying in a circular orbit above the target area, the HAPS 700 maintains a feeder link with the gateway 40 by adjusting the direction of orientation of the FL antenna, and maintains coverage of the target area by the communication area 704 by adjusting the direction of orientation of the SL antenna.

[0061] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0062] It should be noted that the order of execution of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order.

[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 Fixing member, 220 Restraint member, 230 Frame member, 232 Excavation, 240 Unit, 250 Base, 252 Plane, 260 Protrusion, 262 First direction, 264 Second direction, 266 Length, 268 Length, 272 Hollow portion, 274 Top surface, 276 Hole, 280 Plate-shaped member, 700 HAPS, 702 Beam, 704 Communication area, 710 Airframe, 712 Wing portion, 714 Left wing portion, 716 Right wing portion, 720 Center portion, 722 Flight control unit, 724 Communication control unit, 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; and a fixing member for fixing the plurality of units in a state of being pressed against the lithium metal battery.

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, and the length of the protrusion along a first direction parallel to the plane of the base portion is different from the length along a second direction parallel to the plane and different from the first direction. The restraint according to claim 1.

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

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

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

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 the top surface on the side 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 restraint member including a plate-shaped member made of a rubber-based material and having a plate-shaped base portion and a plurality of protrusions on the base portion, and a frame member into which the plate-shaped member is fitted; and a fixing member for fixing 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, wherein at least one of the plurality of protrusions has a hole portion in 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 in the top surface.

10. A battery system comprising the restraint according to any one of claims 1 to 8 and the lithium metal battery.

11. An aircraft comprising the battery system according to claim 10 and a propulsion force generating device that generates a propulsion force by using the electrical energy stored in the battery system.

Images