Binding tool, battery system, and flying body

Abstract

To provide a binding tool that binds a lithium metal battery that has a light weight compared to metal plate binding, and has a structure in which, when the thickness of the lithium metal battery is changed due to charging and discharging, binding pressure against the lithium metal battery is appropriately adjusted.SOLUTION: A binding tool is provided, which binds a lithium metal battery 100 including a plurality of battery cells 110, and comprises: a binding member 210 that has a plate-like member 212 that is made of rubber, and has a plate-like base 214 and a plurality of projections on the base, and a frame member 218 to which the plate-like member is fitted; and a fixing member that presses the plate-like member fitted to the frame member against the lithium metal battery to be fixed in a pressurized state. The pressure applied to the plurality of battery cells caused by elasticity of the plate-like member of the binding tool during charging of the plurality of battery cells is 5 MPa or less, and the pressure against the plurality of battery cells applied by the binding tool during discharging of the plurality of battery cells is 0.1 MPa or more.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Patent document 1 describes a lithium-ion battery in which multiple stacked battery cells are clamped between metal plates and restrained using metal bands, thereby applying restraining pressure to the battery cells in the stacking direction. [Prior art document] [Patent documents] [Patent Document 1] JP 2022-075152 A Summary of the Invention [Means for solving the problem]

[0003] 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 include a plate-shaped member made of a rubber-based material, the plate-shaped member having a plate-shaped base and a plurality of protrusions on the base, and a frame member into which the plate-shaped member is fitted. The restraining device may include a fixing member that presses the plate-shaped member fitted into the frame member against the lithium metal battery and fixes it in a pressurized state.

[0004] In the restraint, each of the plurality of protrusions may have a conical shape. Each of the plurality of protrusions may have a conical shape with a height to diameter ratio between 1:1 and 1:5.

[0005] In any of the above restraint devices, rectangular protrusions having a central cut running along the vertical direction of the base and rectangular protrusions having a central cut running along the horizontal direction of the base may be arranged alternately on the base.

[0006] Due to the elasticity of the plate-shaped member of any of the restraining devices, the pressure applied by the restraining device to the multiple battery cells when the multiple battery cells are charged may be 5 MPa or less, and the pressure applied by the restraining device to the multiple battery cells when the multiple battery cells are discharged may be 0.1 MPa or more. The pressure applied by the restraining device to the multiple battery cells when the multiple battery cells are charged may be 3 MPa or less. The pressure applied by the restraining device to the multiple battery cells when the multiple battery cells are charged may be 2 MPa or less. The pressure applied by the restraining device to the multiple battery cells when the multiple battery cells are discharged may be 0.3 MPa or more. The pressure applied by the restraining device to the multiple battery cells when the multiple battery cells are discharged may be 0.5 MPa or more.

[0007] In any of the above-mentioned restraint devices, the restraint member may include a first restraint member having a first plate-shaped member and a first frame member, and a second restraint member having a second plate-shaped member and a second frame member, and the fixing member may fix the lithium metal battery in a pressurized state by sandwiching it between the first restraint member and the second restraint member.

[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 one embodiment of the present invention, there is provided an aircraft including the battery system and a thrust generating device that generates thrust by utilizing 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. Also, subcombinations of these features may also be inventions. [Brief description of the drawings]

[0010] [Figure 1] 1 illustrates a schematic diagram of an example battery system 10. [Diagram 2] 1 illustrates a schematic diagram of an example battery system 10. [Diagram 3] An example of a plate-like member 212 is shown diagrammatically. [Figure 4] An example of a frame member 218 is shown diagrammatically. [Diagram 5] An example of a plate-like member 212 is shown diagrammatically. [Figure 6] An example of a plate-like member 212 is shown diagrammatically. [Figure 7] An example of a HAPS700 equipped with a battery system 10 is shown in schematic form. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0012] A lithium ion battery can obtain sufficient battery characteristics by restraining it with no pressure or with a low pressure of about 0.0 to 0.2 MPa. On the other hand, it has been discovered that when a lithium metal battery is restrained with the same pressure as that of a lithium ion battery, the cycle life is deteriorated. By increasing the restraining pressure by a method such as metal plate restraint, the cycle life is improved, but the restraining member becomes heavy and the weight energy density is reduced. In addition, the thickness of a lithium metal battery changes due to charging and discharging, but in the case of metal plate restraint, the pressure is not appropriately adjusted, so there is a possibility that the restraining pressure on the lithium metal battery becomes excessive or insufficient. The restraining device 200 according to this embodiment is lighter in weight than metal plate restraint, and has a structure that appropriately adjusts the restraining pressure on the lithium metal battery when the thickness of the lithium metal battery changes due to charging and discharging.

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

[0015] 1 and 2, the restraining device 200 has a restraining member 210, a restraining member 220, and a fixing member 230. The restraining member 210 may be an example of a first restraining member. The restraining member 220 may be an example of a second restraining member. The fixing member 230 fixes the lithium metal battery 100 in a state in which the lithium metal battery 100 is sandwiched and pressurized by the restraining members 210 and 220.

[0016] The restraining device 200 may have only one of the restraining member 210 and the restraining member 220. For example, the restraining device 200 has only the restraining member 210 of the restraining member 210 and the restraining member 220. In this case, a member made of a material having a relatively high hardness and a relatively light weight, such as carbon fiber composite material (CFRP: Carbon Fiber Reinforced Plastics), is arranged on the side of the lithium metal battery 100 opposite to the side on which the restraining member 210 is located. Then, the fixing member 230 presses the restraining member 210 against the lithium metal battery 100 and fixes it in a pressurized state. The fixing member 230 may clamp the lithium metal battery 100 between the member arranged on the side of the restraining member 220 of the lithium metal battery 100 and the restraining member 210 and fix it in a pressurized state.

[0017] In this embodiment, a case in which the restraint device 200 includes a restraint member 210 and a restraint member 220 will be mainly described as an example.

[0018] The restraining member 210 includes a plate-shaped member 212 and a frame member 218. The plate-shaped member 212 may be an example of a first plate-shaped member. The frame member 218 may be an example of a first frame member.

[0019] The plate-shaped member 212 is made of a rubber-based material. A specific example of the material of the plate-shaped member 212 is ethylene propylene diene rubber (EPDM: Ethylene Propylene Diene Monomer), but is not limited to this. Other examples include natural rubber, styrene butadiene rubber, nitrile rubber, butyl rubber, chloroprene rubber, chlorosulfonated polyethylene rubber, acrylic rubber, silicone rubber, and fluororubber, but other materials are also acceptable.

[0020] The plate-shaped member 212 has a plate-shaped base 214 and a plurality of protrusions 216 on the base 214. The base 214 may be an example of a first base. The protrusions 216 may be an example of a first protrusion. The plurality of protrusions 216 may have a configuration that applies pressure to the lithium metal battery 100 as uniformly as possible and is less likely to buckle. The gap between the plurality of protrusions 216 may be 0.05 to 0.3 of the area of ​​the base 214. The gap between the plurality of protrusions 216 may be 0.1 to 0.2 of the area of ​​the base 214.

[0021] The plate-like member 212 is fitted into the frame member 218. The frame member 218 has a recess, into which the plate-like member 212 is fitted. The frame member 218 may be formed from a material that is relatively hard and relatively light in weight. An example of the material of the frame member 218 is CFRP, but is not limited to this.

[0022] Restraint member 220 includes a plate-shaped member 222 and a frame member 228. Restraint member 220 has a similar configuration to restraint member 210. Plate-shaped member 222 may be an example of a second plate-shaped member. Frame member 228 may be an example of a second frame member.

[0023] The plate-shaped member 222 is made of a rubber-based material. A specific example of the material of the plate-shaped member 222 is ethylene propylene diene rubber, but is not limited to this. Other examples include natural rubber, styrene butadiene rubber, nitrile rubber, butyl rubber, chloroprene rubber, chlorosulfonated polyethylene rubber, acrylic rubber, silicone rubber, and fluororubber, but other materials are also acceptable.

[0024] The plate-shaped member 222 has a plate-shaped base 224 and a plurality of protrusions 226 on the base 224. The base 224 may be an example of a second base. The protrusions 226 may be an example of a second protrusion. The plurality of protrusions 226 may have a configuration that applies pressure to the lithium metal battery 100 as uniformly as possible and is less likely to buckle.

[0025] The plate-shaped member 222 is fitted into the frame member 228. The frame member 228 has a recess, into which the plate-shaped member 222 is fitted. The frame member 228 may be formed from a material that is relatively hard and relatively light in weight. An example of the material of the frame member 228 is CFRP, but is not limited to this.

[0026] Fixing member 230 may be any member that can fix lithium metal battery 100 in a state in which it is sandwiched and pressurized by restraining member 210 and restraining member 220. Fixing member 230 may be, for example, a box-shaped member formed of a material that is relatively hard and relatively light in weight, such as CFRP.

[0027] The elasticity of plate-shaped member 212 of restraining member 210 and the elasticity of plate-shaped member 222 of restraining member 220 configures restraining member 210, restraining member 220, and fixing member 230 so that the pressure exerted by restraining device 200 on multiple battery cells 110 of lithium metal battery 100 when the multiple battery cells 110 are charged is 5 MPa or less, and the pressure exerted by restraining device 200 on multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.1 MPa or more. In other words, restraining member 210, restraining member 220, and fixing member 230 are configured so that the pressure exerted on lithium metal battery 100 is 0.1 MPa to 5 MPa even if the thickness of lithium metal battery 100 changes due to charging and discharging. Specifically, in order to achieve such pressure, the restraint device 200 is constructed by adjusting the type of rubber of the plate-shaped member 212, the shape, number, and arrangement of the multiple protrusions 216 of the plate-shaped member 212, the type of rubber of the plate-shaped member 222, the shape, number, and arrangement of the multiple protrusions 226 of the plate-shaped member 222, and the fixing force of the fixing member 230. For example, various variations of restraint device 200 can be created by changing some or all of the type of rubber of plate-shaped member 212, the shape, number, and arrangement of multiple protrusions 216 of plate-shaped member 212, the type of rubber of plate-shaped member 222, the shape, number, and arrangement of multiple protrusions 226 of plate-shaped member 222, and the fixing force of fixing member 230, and actually restraining lithium metal battery 100 with the created restraint device 200. The pressure applied to lithium metal battery 100 when lithium metal battery 100 is charged and discharged is measured using a load cell or the like, and a restraint device 200 in which a pressure of 0.1 MPa to 5 MPa is applied to lithium metal battery 100 can be adopted to create the restraint device 200 of this embodiment.

[0028] Similarly, the elasticity of the plate-shaped member 212 of the restraining member 210 and the elasticity of the plate-shaped member 222 of the restraining member 220 may be configured so that the pressure exerted by the restraining device 200 on the multiple battery cells 110 of the lithium metal battery 100 when the multiple battery cells 110 are charged is 3 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.1 MPa or more.

[0029] Similarly, the elasticity of the plate-shaped member 212 of the restraining member 210 and the elasticity of the plate-shaped member 222 of the restraining member 220 may be configured so that the pressure exerted by the restraining device 200 on the multiple battery cells 110 of the lithium metal battery 100 when the multiple battery cells 110 are charged is 2 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.1 MPa or more.

[0030] Similarly, the elasticity of the plate-shaped member 212 of the restraining member 210 and the elasticity of the plate-shaped member 222 of the restraining member 220 may be configured so that the pressure exerted by the restraining device 200 on the multiple battery cells 110 of the lithium metal battery 100 when the multiple battery cells 110 are charged is 5 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.3 MPa or more.

[0031] Similarly, the elasticity of the plate-shaped member 212 of the restraining member 210 and the elasticity of the plate-shaped member 222 of the restraining member 220 may be configured so that the pressure exerted by the restraining device 200 on the multiple battery cells 110 of the lithium metal battery 100 when the multiple battery cells 110 are charged is 3 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.3 MPa or more.

[0032] Similarly, the elasticity of the plate-shaped member 212 of the restraining member 210 and the elasticity of the plate-shaped member 222 of the restraining member 220 may be configured so that the pressure exerted by the restraining device 200 on the multiple battery cells 110 of the lithium metal battery 100 when the multiple battery cells 110 are charged is 2 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.3 MPa or more.

[0033] Similarly, the elasticity of the plate-shaped member 212 of the restraining member 210 and the elasticity of the plate-shaped member 222 of the restraining member 220 may be configured so that the pressure exerted by the restraining device 200 on the multiple battery cells 110 of the lithium metal battery 100 when the multiple battery cells 110 are charged is 5 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.5 MPa or more.

[0034] Similarly, the elasticity of the plate-shaped member 212 of the restraining member 210 and the elasticity of the plate-shaped member 222 of the restraining member 220 may be configured so that the pressure exerted by the restraining device 200 on the multiple battery cells 110 of the lithium metal battery 100 when the multiple battery cells 110 are charged is 3 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.5 MPa or more.

[0035] Similarly, the elasticity of the plate-shaped member 212 of the restraining member 210 and the elasticity of the plate-shaped member 222 of the restraining member 220 may be configured so that the pressure exerted by the restraining device 200 on the multiple battery cells 110 of the lithium metal battery 100 when the multiple battery cells 110 are charged is 2 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.5 MPa or more.

[0036] When the restraining device 200 has only the restraining member 210 out of the restraining member 210 and the restraining member 220, the restraining member 210 and the fixing member 230 may be configured so that the pressure exerted by the restraining device 200 on the multiple battery cells 110 of the lithium metal battery 100 during charging of the multiple battery cells 110 due to the elasticity of the plate-shaped member 212 of the restraining member 210 is 5 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 during discharging of the multiple battery cells 110 is 0.1 MPa or more. That is, the restraining member 210 and the fixing member 230 are configured so that the pressure exerted on the lithium metal battery 100 is 0.1 MPa to 5 MPa even if the thickness of the lithium metal battery 100 changes due to charging and discharging. Specifically, the restraining device 200 is configured by adjusting the type of rubber of the plate-shaped member 212, the shape, number, and arrangement of the multiple protrusions 216 of the plate-shaped member 212, and the fixing force of the fixing member 230 so as to realize such pressure. For example, various variations of the restraint device 200 can be created by changing some or all of the type of rubber used for the plate-shaped member 212, the shape, number, and arrangement of the multiple protrusions 216 of the plate-shaped member 212, and the fixing force provided by the fixing member 230, and then the lithium metal battery 100 is actually restrained with the created restraint device 200. The pressure applied to the lithium metal battery 100 when the lithium metal battery 100 is charged and discharged is measured using a load cell or the like, and the restraint device 200 that applies a pressure of 0.1 MPa to 5 MPa to the lithium metal battery 100 can be used to create the restraint device 200 of this embodiment.

[0037] Similarly, the restraining member 210 and the fixing member 230 may be configured such that, due to the elasticity of the plate-shaped member 212 of the restraining member 210, the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 of the lithium metal battery 100 are charged is 3 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.1 MPa or more.

[0038] Similarly, the restraining member 210 and the fixing member 230 may be configured such that, due to the elasticity of the plate-shaped member 212 of the restraining member 210, the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 of the lithium metal battery 100 are charged is 2 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.1 MPa or more.

[0039] Similarly, the restraining member 210 and the fixing member 230 may be configured such that, due to the elasticity of the plate-shaped member 212 of the restraining member 210, the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 of the lithium metal battery 100 are charged is 5 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.3 MPa or more.

[0040] Similarly, the restraining member 210 and the fixing member 230 may be configured such that, due to the elasticity of the plate-shaped member 212 of the restraining member 210, the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 of the lithium metal battery 100 are charged is 3 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.3 MPa or more.

[0041] Similarly, the restraining member 210 and the fixing member 230 may be configured such that, due to the elasticity of the plate-shaped member 212 of the restraining member 210, the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 of the lithium metal battery 100 are charged is 2 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.3 MPa or more.

[0042] Similarly, the restraining member 210 and the fixing member 230 may be configured such that, due to the elasticity of the plate-shaped member 212 of the restraining member 210, the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 of the lithium metal battery 100 are charged is 5 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.5 MPa or more.

[0043] Similarly, the restraining member 210 and the fixing member 230 may be configured such that, due to the elasticity of the plate-shaped member 212 of the restraining member 210, the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 of the lithium metal battery 100 are charged is 3 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.5 MPa or more.

[0044] Similarly, the restraining member 210 and the fixing member 230 may be configured such that, due to the elasticity of the plate-shaped member 212 of the restraining member 210, the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 of the lithium metal battery 100 are charged is 2 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.5 MPa or more.

[0045] Table 1 below shows the results of an experiment on the capacity retention rate of the battery cell 110 at 200 cycles for each pressure applied to the battery cell 110 during charging and discharging. Table 1 shows the results of an experiment on the capacity retention rate of the battery cell 110 at 200 cycles for each combination of the pressure at the end of charging, at which the pressure applied to the battery cell 110 is strongest when the battery cell 110 is charged, and the pressure at the end of discharging, at which the pressure on the battery cell 110 is weakest when the battery cell 110 is discharged. The experiment was performed multiple times for each combination of the pressure applied to the battery cell 110 during charging and the pressure applied to the battery cell 110 during discharging, and the results are shown as follows: "x" indicates that the number of cycles was 200 or less to begin with; "△" indicates that the capacity retention rate at 200 cycles was less than 70%; "◯" indicates that the capacity retention rate at 200 cycles was 70% or more but less than 90%; and "◎" indicates that the capacity retention rate at 200 cycles was 90% or more.

[0046] The experimental results show that, for example, when the battery cell 110 was charged and discharged 200 times under conditions of a pressure of 2 MPa at the end of charging and a pressure of 0.3 MPa at the end of discharging, the capacity retention rate of the battery cell 110 was 90% or more.

[0047] The experimental results show that by setting the pressure applied during charging to a maximum of 2 MPa or 3 MPa and the pressure applied during discharging to a minimum of 0.3 MPa, 0.5 MPa, or 0.6 MPa, the capacity retention rate of the lithium metal battery 100 is 90% or more when the battery cell 110 is charged and discharged 200 times.

[0048] [Table 1]

[0049] As shown in Table 1, the charge pressure is preferably 0.8 MPa to 6 MPa, more preferably 1 MPa to 5 MPa, more preferably 1 MPa to 4 MPa, and even more preferably 2 MPa or 3 MPa. The discharge pressure is preferably 0.1 MPa to 0.6 MPa, more preferably 0.2 MPa to 0.6 MPa, and even more preferably 0.3 MPa to 0.6 MPa.

[0050] As shown in Table 1, it is preferable that the charging pressure is 1 MPa to 4 MPa and the discharging pressure is 0.2 MPa to 0.6 MPa, and it is even more preferable that the charging pressure is 2 MPa or 3 MPa and the discharging pressure is 0.3 MPa to 0.6 MPa. According to the restraint device 200 of the present embodiment, it is possible to restrain the lithium metal battery 100 so as to satisfy such range conditions, which can contribute to maintaining the performance of the lithium metal battery 100.

[0051] 3 shows a schematic diagram of an example of the plate member 212. The dimensions of the plate member 212 shown in FIG. 3 are merely an example. The dimensions of the plate member 212 may be determined according to the material of the plate member 212, etc., so that the pressure exerted by the restraining device 200 on the multiple battery cells 110 of the lithium metal battery 100 when the multiple battery cells 110 are charged is 5 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.1 MPa or more. The plate member 222 may have the same configuration as the plate member 212.

[0052] 3, the base 214 is 93 mm long, 66 mm wide, and 4 mm high. The protrusion 216 has a rectangular shape. The protrusion 216 is 12 mm long, 12 mm wide, and 10 mm high. The multiple protrusions 216 are arranged side by side in the vertical and horizontal directions. The distance between the multiple protrusions 216 is 2 mm.

[0053] By having the plate-like member 212 have such a structure, the multiple protrusions 216 are less likely to buckle, and while uniform pressure is applied to the battery cell 110, it is possible to appropriately adjust the pressure applied to the lithium metal battery 100 when the thickness of the lithium metal battery 100 changes. In addition, it is possible to reduce the possibility that the lithium metal battery 100 will become misaligned due to friction between the multiple protrusions 216 and the lithium metal battery 100.

[0054] FIG. 4 shows a schematic diagram of an example of the frame member 218. The dimensions shown in FIG. 4 are merely an example, and other dimensions may be used. The frame member 218 has a recess 219. The depth of the recess 219 may be the same as the height of the base 214. The depth of the recess 219 may be one-tenth to one-half the height of the base 214. The depth of the recess 219 may be one-fifth to one-third the height of the base 214. The frame member 228 may have the same configuration as the frame member 218.

[0055] 5 shows a schematic diagram of an example of the plate-shaped member 212. The dimensions of the plate-shaped member 212 shown in FIG. 5 are merely an example. The dimensions of the plate-shaped member 212 may be determined according to the material of the plate-shaped member 212, etc., so that the pressure exerted by the restraining device 200 on the multiple battery cells 110 of the lithium metal battery 100 when the multiple battery cells 110 are charged is 5 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.1 MPa or more. The plate-shaped member 222 may have the same configuration as the plate-shaped member 212.

[0056] In the example shown in FIG. 5, the base 214 is 93 mm long, 66 mm wide, and 4 mm high. In the example shown in FIG. 5, rectangular protrusions 2162 with a notch in the center along the vertical direction of the base 214 and rectangular protrusions 2164 with a notch in the center along the horizontal direction of the base 214 are arranged alternately on the base 214. In the example shown in FIG. 5, the overall dimensions of the protrusions 2162 and 2164 are 12 mm long, 12 mm wide, and 10 mm high. The width of the notch is 6 mm, and the height of the notch is 8 mm. That is, the depth of the notch is 2 mm. The distance between the protrusions 2162 and 2164 is 2 mm.

[0057] As shown in Figure 5, by arranging the protrusions with cuts in different directions alternately, in addition to the advantages of the structure shown in Figure 3, the directionality of the rubber deformation can be canceled, and the possibility of excessive pressure being applied to part of the battery cell 110, causing damage to the battery cell 110, can be reduced.

[0058] Fig. 6 shows a schematic diagram of an example of the plate member 212. The dimensions of the plate member 212 shown in Fig. 6 are merely an example. The dimensions of the plate member 212 may be determined according to the material of the plate member 212, etc., so that the pressure exerted by the restraining device 200 on the multiple battery cells 110 of the lithium metal battery 100 when the multiple battery cells 110 are charged is 5 MPa or less, and the pressure exerted by the restraining device 200 on the multiple battery cells 110 when the multiple battery cells 110 are discharged is 0.1 MPa or more. The plate member 222 may have the same configuration as the plate member 212.

[0059] In the example shown in FIG. 6, the base 214 is 93 mm long, 66 mm wide, and 4 mm high. The protrusion 216 has a cone shape. The apex side of the protrusion 216 may be curved. The apex side of the protrusion 216 may be flat. The ratio of the height to the diameter of the protrusion 216 may be between 1:1 and 1:5. The ratio of the height to the diameter of the protrusion 216 may be 1:3. The diameter of the bottom surface of the protrusion 216 may be 5 mm to 30 mm. In the example shown in FIG. 6, the diameter of the bottom surface of the protrusion 216 is 12 mm, and the height is 10 mm. The protrusion 216 may be a quadrangular pyramid shape.

[0060] By having the plate-like member 212 have such a structure, the multiple protrusions 216 are less likely to buckle, and while uniform pressure is applied to the battery cell 110, it is possible to appropriately adjust the pressure applied to the lithium metal battery 100 when the thickness of the lithium metal battery 100 changes. In addition, it is possible to reduce the possibility that the lithium metal battery 100 will become misaligned due to friction between the multiple protrusions 216 and the lithium metal battery 100.

[0061] 7 shows a schematic diagram of an example of a HAPS 700 equipped with a battery system 10. The HAPS 700 is an aircraft 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 aircraft that includes the battery system 10 and a thrust generating device that generates thrust using electrical energy stored in the battery system 10.

[0062] The HAPS 700 includes a body 710, a center section 720, a propeller 730, a pod 740, and solar panels 750. The body 710 includes a wing section 712. The wing section 712 includes a left wing section 714 and a right wing section 716.

[0063] For example, the 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 HAPS700. For example, the electric energy stored in the battery system 10 is utilized by the motor of the propeller 730 that generates a propulsive 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 plurality of battery systems 10 on the left side may be disposed in the left wing section 714, and the plurality of battery systems 10 on the right side 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 HAPS700. For example, the electric power discharged by the plurality of battery systems 10 is utilized by the motor of the propeller 730.

[0064] 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.

[0065] 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 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, and may manage the position, movement direction, and movement speed of the HAPS 700.

[0066] The communication control unit 724 uses a service link (SL) antenna to form a communication area 704 on the ground. The communication control unit 724 uses the SL antenna to form a service link with a terrestrial user terminal 30. The SL antenna may be a multi-beam antenna. The communication area 704 may be a multi-cell.

[0067] The communication control unit 724 may use a FL (Feeder Link) antenna to form a feeder link with the ground gateway 40. The communication control unit 724 may access the network 20 via the gateway 40.

[0068] The communication control unit 724 may use the 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.

[0069] 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 be a tablet terminal, a PC (Personal Computer), or the like. The user terminal 30 may 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).

[0070] The HAPS 700 relays communication between the network 20 and the user terminal 30 via, for example, a feeder link or a communication satellite 50 and a service link. The HAPS 700 may provide a wireless communication service to the user terminal 30 by relaying communication between the user terminal 30 and the network 20.

[0071] The network 20 includes a mobile communication network. The mobile communication network may be compliant with any of the following communication methods: LTE (Long Term Evolution), 5G (5th Generation), 3G (3rd Generation), and 6G (6th Generation) or later. The network 20 may include the Internet.

[0072] 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.

[0073] The HAPS700 maintains a communication area 704 in a specific area on the ground while circulating along a predetermined flight path in the stratosphere, for example. The HAPS700 stores power generated by the solar cell panels 750 in the multiple battery systems 10 during the day, and maintains flight in the stratosphere by using the power of the multiple battery systems 10 at night. The HAPS700 maintains flight in the stratosphere, for example, by ascending and storing potential energy while charging the multiple battery systems 10 during the day, and by slowly descending at night and appropriately operating the propellers 730 and the like using the power of the battery systems 10.

[0074] The management device 800 manages multiple HAPS 700. The management device 800 may communicate with the HAPS 700 via the network 20 and the gateway 40. The management device 800 may communicate with the HAPS 700 via the network 20, the satellite communication station 60, and the communication satellite 50.

[0075] 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.

[0076] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the description of the claims that such modifications and improvements can also be included in the technical scope of the present invention.

[0077] 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" or "prior to," and that the process may be performed in any order unless the output of a previous process is used in a later process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," and the like for convenience, this does not mean that the process must be performed in this order. [Explanation of symbols]

[0078] 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 restraint member, 212 plate-shaped member, 214 base, 216 protrusion, 2162 protrusion, 2164 protrusion, 218 frame member, 219 recess, 220 restraint member, 222 plate-shaped member, 224 base, 226 protrusion, 228 frame member, 230 fixing member, 700 HAPS, 702 beam, 704 communication area, 710 fuselage, 712 wing, 714 left wing, 716 right wing, 720 center, 722 flight control unit, 724 communication control unit, 730 propeller, 740 Pod, 750 solar panels, 800 management equipment

Claims

1. A restraint for restraining a lithium metal battery including a plurality of battery cells, comprising: A plate-like member made of a rubber material and having a plate-like base and a plurality of protrusions on the base; a frame member into which the plate-like member is fitted; A restraining member having a fixing member that presses the plate-shaped member fitted in the frame member against the lithium metal battery and fixes it in a pressurized state; A restraint device comprising:

2. The restraint of claim 1 , wherein each of the plurality of protrusions has a conical shape.

3. 3. The restraint of claim 2, wherein each of the plurality of protrusions has a conical shape with a height to diameter ratio between 1:1 and 1:

5.

4. The restraint device according to claim 1, wherein on the base, rectangular protrusions each having a central cut extending along the vertical direction of the base and rectangular protrusions each having a central cut extending along the horizontal direction of the base are arranged alternately.

5. 5. The restraint device according to claim 1, wherein due to the elasticity of the plate-shaped member, the pressure exerted by the restraint device on the multiple battery cells when the multiple battery cells are being charged is 5 MPa or less, and the pressure exerted by the restraint device on the multiple battery cells when the multiple battery cells are being discharged is 0.1 MPa or more.

6. The restraint device according to claim 5 , wherein a pressure exerted by the restraint device on the plurality of battery cells during charging of the plurality of battery cells is 3 MPa or less.

7. The restraint device according to claim 6 , wherein a pressure exerted by the restraint device on the plurality of battery cells during charging of the plurality of battery cells is 2 MPa or less.

8. The restraint device according to claim 5 , wherein a pressure applied to the plurality of battery cells by the restraint device during discharge of the plurality of battery cells is 0.3 MPa or more.

9. The restraint device according to claim 8 , wherein a pressure applied by the restraint device to the plurality of battery cells during discharge of the plurality of battery cells is 0.5 MPa or more.

10. the restraining member includes a first restraining member having a first plate-like member and a first frame member, and a second restraining member having a second plate-like member and a second frame member, The restraint device according to claim 1 , wherein the fixing member fixes the lithium metal battery in a state in which the lithium metal battery is sandwiched and pressurized by the first restraint member and the second restraint member.

11. The restraint device according to claim 1; The lithium metal battery. A battery system comprising:

12. The battery system according to claim 11 ; a thrust generating device that generates thrust by utilizing the electric energy stored in the battery system; An aircraft equipped with the above.

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