Battery module

Abstract

To provide a battery module capable of easily adjusting cooling performance on battery cells.SOLUTION: The battery module includes: a battery cell 220 with multiple laminates; a cool storage tube 230 that is placed between adjacent battery cells 220 with a protrusion 232 protruding in at least one direction from the battery cell 220 for exchanging heat between the battery cells; and an attaching / detaching part 240 of an immersion cooling device 400 for supplying cooling liquid 420 for cooling the protrusion 232 to the protrusion 232.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Conventionally, Patent Document 1 describes a battery module having a heat receiving part sandwiched between battery cells to receive heat from the battery cells, and a cooling part formed integrally with the heat receiving part and projecting from the battery cells. In this conventional technology, a cooling fluid is supplied to the cooling part to efficiently dissipate heat from the battery cells. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-243358 A Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, when a battery module is mounted on an electric aircraft, for example, the required cooling performance differs between when the electric aircraft is in flight and when it is on the ground after landing. That is, since a reduction in weight is required when the electric aircraft is in flight, it is required to ensure a minimum cooling performance while simplifying the configuration required for cooling the battery pack. On the other hand, when the electric aircraft is on the ground, high-performance cooling is required to deal with heat generation due to rapid charging of the battery pack.

[0005] In view of the above, an object of the present invention is to provide a battery module that can easily adjust the cooling performance for the battery cells. [Means for solving the problem]

[0006] In order to achieve the above object, the battery module according to claim 1 comprises a plurality of stacked battery cells (220); a heat transfer member (230, 230A) disposed between adjacent battery cells, having a protrusion (232, 232A) protruding in at least one direction from the battery cell, and transferring heat between the battery cells; and a detachable portion (240, 254) to which a cooling portion (400, 600, 800) that supplies a cooling fluid (420) for cooling the protrusion to the protrusion is detached.

[0007] With this, the cooling method of the protrusions (232, 232A) can be switched and the cooling performance for the battery cells (220) can be adjusted simply by attaching and detaching the cooling sections (400, 600, 800) to and from the detachable sections (240, 254). Therefore, the cooling performance for the battery cells can be easily adjusted.

[0008] In addition, the reference symbols in parentheses for each means described in this column and in the claims indicate the correspondence with the specific means described in the embodiments described later. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of an eVTOL in a first embodiment. [Diagram 2] FIG. 2 is an explanatory diagram showing the battery cooling system in an air-cooling mode in the first embodiment. [Diagram 3] FIG. 2 is an explanatory diagram showing the battery cooling system in an immersion cooling mode in the first embodiment. [Figure 4] FIG. 4 is a diagram showing changes in battery output and battery temperature from takeoff to landing of the eVTOL in the first embodiment. [Diagram 5] FIG. 11 is an explanatory diagram showing a battery cooling system in a cool air cooling mode in a second embodiment. [Figure 6] FIG. 11 is an explanatory diagram showing a battery cooling system in an air-cooling mode in a third embodiment. [Figure 7] FIG. 13 is an explanatory diagram showing a battery pack in a fourth embodiment. [Figure 8] FIG. 13 is an explanatory diagram showing a battery pack in a fifth embodiment. [Figure 9] FIG. 13 is an explanatory diagram showing a battery pack in a sixth embodiment. [Figure 10] FIG. 13 is an explanatory diagram showing a battery pack in a seventh embodiment. [Figure 11] FIG. 13 is an explanatory diagram showing a battery pack in an eighth embodiment. [Figure 12] FIG. 13 is an explanatory diagram showing a battery pack in a ninth embodiment. [Figure 13] FIG. 23 is an explanatory diagram showing the battery cooling system in the planar cooling mode in the tenth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, the same reference numerals may be used to designate parts corresponding to matters described in the preceding embodiment, and duplicated descriptions may be omitted. In each embodiment, when only a part of the configuration is described, the other embodiment described previously may be applied to the other parts of the configuration.

[0011] It is possible to combine parts of each embodiment that are specifically indicated as being possible to combine with each other. In addition, even if it is not specifically indicated that the combination is possible, it is also possible to combine parts of each embodiment with each other, as long as there is no particular problem with the combination.

[0012] (First embodiment) The battery module according to this embodiment is mounted on an electric vehicle. The electric vehicle is an electric flying object, an electric vehicle, etc. The electric flying object is capable of flying by being driven by a rotating electric machine.

[0013] Examples of electric flying objects include electric vertical take-off and landing aircraft (eVTOL), electric short take-off and landing aircraft (eSTOL), drones, etc. eVTOL is an abbreviation for electronic Vertical Take-Off and Landing aircraft. eSTOL is an abbreviation for electronic Short distance Take-Off and Landing aircraft. Below, an example in which a battery module is mounted on an eVTOL will be described.

[0014] <evtol> As shown in FIG. 1, as an example, an eVTOL 100 of this embodiment includes an aircraft body 110, a fixed wing 120, a rotor 130, a lift control mechanism 140, a battery module 200, an EPU 150, a BMS 160, and an ECU 170.

[0015] The aircraft body 110 is the fuselage of the aircraft. The aircraft body 110 has a shape that extends in the front-rear direction. The aircraft body 110 has a passenger compartment for passengers to ride in and / or a luggage compartment for carrying luggage.

[0016] The fixed wing 120 is a wing portion of the aircraft, and is connected to the aircraft body 110. The fixed wing 120 provides gliding lift. The gliding lift is the lift generated by the fixed wing 120. As an example, the fixed wing 120 has a main wing 121 and a tail 122. The main wing 121 extends left and right from near the center in the fore-and-aft direction of the aircraft body 110. The tail 122 extends left and right from the rear of the aircraft body 110. The shape of the fixed wing 120 is not particularly limited. For example, a swept back wing, a delta wing, a straight wing, etc. can be adopted.

[0017] A plurality of rotors 130 are provided on the aircraft body. At least some of the plurality of rotors 130 may be provided on the fixed wing 120. At least some of the plurality of rotors 130 may be provided on the aircraft body 110. The number of rotors 130 provided on the eVTOL 100 is not particularly limited. As an example, a plurality of rotors 130 are provided on each of the aircraft body 110 and the main wing 121. The eVTOL 100 has six rotors 130.

[0018] The rotor 130 may be referred to as a rotor, a propeller, a fan, or the like. The rotor 130 has blades 131 and a shaft 132. The blades 131 are attached to the shaft 132. The blades 131 are vanes that rotate together with the shaft 132. A plurality of the blades 131 extend radially around the axis of the shaft 132. The shaft 132 is a rotation axis of the rotor 130, and is driven to rotate by a motor of the EPU 150.

[0019] The rotor 130 generates a thrust by rotation. The thrust acts on the eVTOL 100 mainly as a rotational lift when the eVTOL 100 takes off or lands. The rotor 130 mainly provides a rotational lift when the eVTOL 100 takes off or lands. The rotational lift is a lift generated by the rotation of the rotor 130. When the eVTOL 100 takes off or lands, the rotor 130 may provide only the rotational lift, or may provide a forward thrust in addition to the rotational lift. The rotor 130 provides a rotational lift when the eVTOL 100 is hovering.

[0020] The propulsive force acts mainly as thrust on the eVTOL 100 during cruising of the eVTOL 100. The rotor 130 mainly provides thrust during cruising. During cruising, the rotor 130 may provide only thrust, or may provide lift in addition to thrust.

[0021] The lift adjustment mechanism 140 adjusts the gliding lift of the fixed wing 120. The lift adjustment mechanism 140 increases or decreases the gliding lift generated by the fixed wing 120. The lift adjustment mechanism 140 adjusts the gliding lift by adjusting at least one of the surface area, angle of attack (AOA), camber (wing curvature), stall AOA, and wing speed of the fixed wing 120, for example. AOA is an abbreviation for Angle Of Attack. As an example, the lift adjustment mechanism 140 has a tilt mechanism 141 and a flap 142.

[0022] The tilt mechanism 141 is driven to adjust the tilt angle of the rotor 130. The tilt mechanism 141 constitutes a tilt adjustment device together with a motor, an inverter, and the like that drive the tilt mechanism 141. The tilt adjustment device including the tilt mechanism 141 is provided, for example, individually for each rotor 130. The tilt mechanism 141 adjusts the tilt angle of the rotor 130 by adjusting the relative inclination of the rotor 130 with respect to the airframe.

[0023] During takeoff and landing, the tilt mechanism 141 controls the tilt angle so that the axis of each rotor 130 approaches a position parallel to the vertical direction. As a result, the propulsive force caused by the rotation of each rotor 130 acts on the eVTOL 100 mainly as rotational lift. Therefore, the eVTOL 100 can take off and land in a short distance or in a vertical direction. In FIG. 1, the vertical direction is the direction perpendicular to the paper surface.

[0024] During cruising, the tilt mechanism 141 controls the tilt angle so that the axis of each rotor 130 approaches a position parallel to the horizontal direction. As a result, the propulsive force generated by the rotation of each rotor 130 acts on the eVTOL 100 mainly as thrust. Therefore, the eVTOL 100 can move forward by the forward thrust generated by the rotation of each rotor 130 while obtaining gliding lift from the fixed wing 120. In addition, the gliding lift can be adjusted by changing the wing speed using the thrust.

[0025] Although an example in which the tilt mechanisms 141 are provided individually for the rotors 130 has been described, the present invention is not limited to this. For example, the tilt angles of multiple rotors 130 arranged side by side may be controlled by a common tilt mechanism. A configuration in which the rotors 130 are integrated with a part of the wing portion, and the part of the wing portion and the rotors 130 are displaced together by the tilt mechanism, may also be used.

[0026] The flap 142 is a movable wing piece and is provided on the fixed wing 120. The flap 142, together with a motor, an inverter, and the like that drive the flap 142, constitutes a flap adjustment device. The flap 142 is sometimes referred to as a high-lift device. As an example, a plurality of flaps 142 are provided on the trailing edge of the main wing 121. Each of the plurality of flaps 142 is provided with a motor and an inverter. The flap 142 may be provided on the tail 122 in addition to the main wing 121. The flap 142 may be provided on the leading edge of the fixed wing 120.

[0027] The flap 142 adjusts the surface area and camber of the fixed wing 120. For example, by controlling the flap 142 provided on the main wing 121 to a lower position, the gliding lift acting on the main wing 121 increases. In addition, by moving the flap 142 in a direction protruding from the main wing 121, it is possible to further increase the gliding lift.

[0028] The lift adjustment mechanism 140 is not limited to the tilt mechanism 141 and the flap 142 described above. A tilt mechanism that adjusts the relative inclination of the fixed wing 120 with respect to the aircraft body 110 may be adopted as the lift adjustment mechanism 140. In this case, the angle of attack of the fixed wing 120 can be adjusted. A rotor for thrust provided separately from the rotor 130 may be adopted as the lift adjustment mechanism 140. In this case, the wing speed can be adjusted. Also, by providing a rotor for thrust, it is possible to use the rotor 130 exclusively for lift (i.e., rotational lift).

[0029] A variable wing may be used as the lift adjustment mechanism 140. Lift can be adjusted by changing the surface area, camber, angle of attachment, etc. of the fixed wing 120. A high-lift device other than the flap 142, for example a slat, may be used as the lift adjustment mechanism 140. The slat is provided on the leading edge of the main wing 121. By operating the slat forward relative to the main wing 121, a gap is created between the slat and the main wing 121, and separation can be delayed. Thus, lift can be increased without stalling up to a higher angle of attack. In other words, the stall AOA can be delayed.

[0030] The battery module 200 has a plurality of battery cells, which will be described later, and is a device capable of cooling each battery cell. Each battery cell is capable of storing DC power and is a rechargeable secondary battery. Each battery cell supplies power to the EPU 150, the ECU 170, the tilt adjustment device, and the flap adjustment device. Each battery cell also supplies power to auxiliary equipment (not shown), such as an air conditioner.

[0031] As an example, the eVTOL 100 of the present embodiment includes a plurality of battery modules 200. The plurality of battery modules 200 may be connected to each other in series and / or parallel, or may be arranged independently without being connected to each other. The battery modules 200 may be provided separately for the EPU 150, or may be provided redundantly for the EPU 150.

[0032] Here, since the multiple battery cells include, for example, tens or hundreds of cells, the battery module 200 is heavy. Therefore, by arranging each battery module 200 at two locations on each side of the main wing 121, the aircraft body 110 can be balanced. Of course, the battery module 200 may be arranged in the aircraft body 110.

[0033] The EPU 150 has a motor and an inverter, and rotates and drives the rotors 130 that impart a propulsive force to the eVTOL 100. EPU is an abbreviation for Electric Propulsion Unit. As an example, the same number of EPUs 150 as the rotors 130 are provided. In other words, the eVTOL 100 includes six EPUs 150. The EPUs 150 and the rotors 130 are connected one-to-one. Alternatively, a configuration in which two or more rotors 130 are connected to one EPU 150 via a gear box may be used.

[0034] The BMS 160 monitors the state of each battery pack 260 (see FIG. 2 described later) of the battery module 200. BMS is an abbreviation for Battery Management System. For example, one BMS 160 is provided for one battery module 200. The BMS 160 may, for example, predict or detect an abnormality in each battery module 200 by monitoring the state of each battery pack of the multiple battery modules 200.

[0035] The ECU 170 controls the flight of the eVTOL 100. ECU is an abbreviation for Electronic Control Unit. The ECU 170 performs control to fly the eVTOL 100 in a flight state according to operation by a pilot as an operator, remote operation by an operator, or control by a control system. The ECU 170 performs flight control based on detection results of the BMS 160 and various sensors. The ECU 170 controls the drive of, for example, the motor of the EPU 150, the motor of the tilt adjustment device, and the motor of the flap adjustment device. The ECU 170 may perform control of auxiliary equipment.

[0036] <Battery cooling system> 2 and 3, the battery cooling system 300 includes a battery module 200, an immersion cooling device 400, and the like. The up-down direction when the eVTOL 100 is stationary on the ground is referred to as the vertical direction. In the vertical direction, the upper side refers to the sky and the lower side refers to the ground.

[0037] The battery module 200 includes a storage case 210 , a battery cell 220 , a cold storage tube 230 , a detachable section 240 , and an air-cooling duct 250 .

[0038] The storage case 210 is a housing that houses the battery cells 220 and the cold storage tubes 230. The storage case 210 has an outer wall surface 211 and an inner wall surface 212, and also has a space 213 inside. The storage case 210 is formed using, for example, an aluminum-based metal material or a resin material. As an example, the storage case 210 of this embodiment is formed using an aluminum-based material.

[0039] For example, the upper portion of the storage case 210 in the top-bottom direction may be configured as the lid 2100. The lid 2100 can be attached to and detached from the other portions. This allows the battery cells 220 and the cold storage tubes 230 to be inserted and removed from the space 213 of the storage case 210.

[0040] The battery cell 220 is a secondary battery that generates an electromotive force by a chemical reaction. The battery cell 220 is, for example, a lithium ion secondary battery, a nickel-metal hydride secondary battery, an organic radical battery, etc. The battery cell 220 may be a secondary battery with a liquid electrolyte, or may be a so-called all-solid-state battery with a solid electrolyte.

[0041] A plurality of battery cells 220 are housed in the space 213 of the housing case 210. The plurality of battery cells 220 have a common structure. The number and arrangement of the plurality of battery cells 220 are not particularly limited. The plurality of battery cells 220 may be connected in series, or may be connected in parallel and in series. As an example, the battery cells 220 in this embodiment are connected in series. An electrically connected structure of the plurality of battery cells 220 is sometimes called a battery pack.

[0042] The battery cell 220 has a power generating element and a battery case that houses the power generating element. The battery case provides an outer shell of the battery cell 220. The battery case is formed, for example, using a metal material. The shape of the battery cell 220, that is, the battery case, is not particularly limited. The shape of the battery case may be, for example, a cylindrical shape, a rectangular shape, or the like. As an example, the battery cell 220 of this embodiment has a rectangular shape, specifically, a thin flat shape.

[0043] The battery cell 220 is, for example, a laminated battery. The battery cell 220 has a top surface, a bottom surface, and four side surfaces. The top surface is the surface facing the sky in the vertical direction. The bottom surface is the surface opposite the top surface in the vertical direction and faces the ground. The side surface is a surface that connects the top surface and the bottom surface and is a surface along the vertical direction.

[0044] The multiple battery cells 220 are arranged side by side in a direction perpendicular to the top-bottom direction. A cold storage tube 230 is arranged between adjacent battery cells 220. Each battery cell 220 has two electrode terminals.

[0045] One electrode terminal is electrically connected to the positive electrode of the battery cell 220. One electrode terminal may be referred to as a positive electrode terminal, a P terminal, etc. The other electrode terminal is electrically connected to the negative electrode of the battery cell 220. The other electrode terminal may be referred to as a negative electrode terminal, an N terminal, etc. The electrode terminal may be referred to as a current collecting tab.

[0046] The cold storage tube 230 is a heat transfer member that transfers heat between the cold storage tube 230 and the battery cell 220. The cold storage tube 230 is also a cold storage member that has a built-in cold storage material 231. That is, the inside of the cold storage tube 230 is filled with the cold storage material 231. In this embodiment, the entire inside of the cold storage tube 230 is filled with the cold storage material 231.

[0047] The cold storage material 231 is a member that exhibits a cold storage effect. The cold storage material 231 cools the battery cells 220 by absorbing heat generated in the battery cells 220. The cold storage material 231 is, for example, a latent heat cold storage material. As the cold storage material 231, water or cooling water to which LLC has been added may be used instead of the latent heat cold storage material. LLC is an abbreviation for Long Life Coolant. The cold storage material is sometimes referred to as a heat storage material.

[0048] As an example, the cold storage material 231 of this embodiment is a latent heat cold storage material. The latent heat cold storage material is sometimes called PCM. PCM is an abbreviation for Phase change material. The latent heat cold storage material changes phase between solid and liquid. The latent heat cold storage material utilizes the latent heat of a substance. The latent heat cold storage material maintains the temperature of the battery cell 220 at a predetermined temperature or within a predetermined temperature range. For example, a non-hydrate carbon compound, specifically a paraffin-based material, may be used as the latent heat cold storage material. Instead of a paraffin-based material, a hydrate-based material may be used as the latent heat cold storage material. The hydrate-based material is, for example, a hydrate such as sodium acetate, sodium sulfate, or sodium nitrate.

[0049] As an example, the cold storage material 231 of this embodiment is a non-hydrate carbon compound, that is, a paraffin-based cold storage material. The phase transition temperature of the cold storage material 231 between the solid phase and the liquid phase is set within the range of 30°C to 60°C.

[0050] A plurality of cold storage tubes 230 are arranged in the space 213 of the housing case 210. Each cold storage tube 230 is arranged between adjacent battery cells 220. The cold storage tubes 230 and the battery cells 220 are in thermal contact with each other.

[0051] In order to improve the adhesion between the battery cell 220 and the cold storage tube 230, a thermally conductive material 235 may be interposed between the battery cell 220 and the cold storage tube 230. The thermally conductive material 235 is generally called TIM, and is a thermally conductive grease, a thermally conductive gel, or a thermally conductive sheet. TIM is an abbreviation for Thermal Interface Material. As an example, in this embodiment, a thermally conductive sheet is used as the thermally conductive material 235.

[0052] The plurality of battery cells 220 and the cold storage tubes 230 stacked as described above constitute a battery pack 260. Hereinafter, the stacking direction of the battery cells 220 in the battery pack 260 will be referred to as the cell stacking direction.

[0053] A pair of end plates 261 are provided at both ends in the cell stacking direction of the battery pack 260. The pair of end plates 261 are restraining members that apply a restraining load to the multiple battery cells 220 and the multiple cold storage tubes 230 from the outside in the cell stacking direction.

[0054] The pair of end plates 261 are connected to each other by a restraining band 262. The restraining band 262 is a fixing member that fixes the relative positions of the multiple battery cells 220 and the multiple cold storage tubes 230.

[0055] The battery cells 220 and the cold storage tubes 230 are arranged such that the positions of their upper surfaces are substantially equal to each other in the vertical direction. Each of the cold storage tubes 230 has a protruding portion 232 that protrudes from the battery cell 220 in at least one direction. As an example, the protruding portion 232 in this embodiment protrudes from the battery cells 220 in a direction perpendicular to the cell stacking direction. More specifically, the protruding portion 232 protrudes from the lower surfaces of the battery cells 220 in the vertical direction toward the ground.

[0056] In this embodiment, the protruding portion 232 is provided with a safety valve 234. The safety valve 234 opens when the internal pressure of the cold storage tube 230 becomes equal to or higher than a predetermined reference pressure, and releases the cold storage material 231 to the outside of the storage case 210. The safety valve 234 is provided in a portion of the protruding portion 232 that is located outside the storage case 210. In this embodiment, as an example, the safety valve 234 is disposed at an end of the protruding portion 232 on the ground side in the top-to-bottom direction.

[0057] In the above-described arrangement, the electrode terminals of adjacent battery cells 220 are electrically connected to each other by a bus bar (not shown) that is a wiring member. In other words, the multiple battery cells 220 are connected in series by the bus bar.

[0058] Two bus bars, one for a positive electrode and one for a negative electrode, protrude from space 213 of accommodating case 210 to the outside of accommodating case 210. When accommodating case 210 is made of a metal material, an insulating part (not shown) such as an insulating sealant is disposed in a portion of accommodating case 210 through which the bus bars penetrate, thereby achieving electrical insulation between accommodating case 210 and the bus bars.

[0059] Here, the storage case 210 has a plurality of case through holes 214, for example, on the ground side in the top-to-bottom direction. A protruding portion 232 of the cold storage tube 230 is inserted into each case through hole 214. The protruding portion 232 protrudes from the case through hole 214 to the ground side in the top-to-bottom direction. In other words, the protruding portion 232 protrudes from the storage case 210 to the outside through the case through hole 214.

[0060] A seal member 215 is provided inside the storage case 210. The seal member 215 constitutes a seal portion that seals between the storage case 210 and the cold storage tube 230. The seal member 215 is provided on the inside of the portion of the storage case 210 that faces the ground in the top-to-bottom direction.

[0061] The material of the sealing member 215 is not particularly limited. For example, a rubber sheet, an adhesive material, or the like can be used as the sealing member 215. As an example, in this embodiment, a rubber sheet is used as the sealing member 215. The rubber sheet may be formed with an insertion portion through which the cold storage tube 230 is inserted. As the insertion portion, a cut, a through hole, or the like can be used.

[0062] The detachable part 240 is a connection part for attaching and detaching the air-cooling duct 250 and the immersion cooling device 400 to and from the storage case 210 of the battery module 200. The air-cooling duct 250 and the immersion cooling device 400 are configured to be detachable from the detachable part 240.

[0063] Incidentally, weight reduction is required when the eVTOL 100 is flying, that is, during takeoff, cruising, and landing, so it is necessary to ensure a minimum level of cooling performance while simplifying the configuration required for cooling the battery cells 220. On the other hand, when the eVTOL 100 is on the ground, high-performance cooling is required to deal with heat generation and the like associated with rapid charging of the battery cells 220.

[0064] Therefore, the battery module 200 of this embodiment is configured to be switchable between an in-flight cooling mode and a ground cooling mode as cooling modes for cooling the battery cells 220. The in-flight cooling mode is a cooling mode for cooling the battery cells 220 when the eVTOL 100 is flying, that is, when taking off, cruising, and landing. The ground cooling mode is a cooling mode for cooling the battery cells 220 when the eVTOL 100 is on the ground.

[0065] In this embodiment, an air-cooling mode in which an air-cooling duct 250 is attached to the detachment part 240 is adopted as the in-flight cooling mode. Also, an immersion cooling mode in which an immersion cooling device 400 is attached to the detachment part 240 is adopted as the ground cooling mode. Therefore, the battery module 200 of this embodiment is configured to be switchable between the air-cooling mode and the immersion cooling mode.

[0066] As an example, in this embodiment, the detachable part 240 is provided on the outside of the portion of the housing case 210 facing the ground in the vertical direction. That is, the detachable part 240 is provided on the lower surface of the housing case 210 in the vertical direction.

[0067] Hereinafter, an air-cooling mode in which the air-cooling duct 250 is attached to the detachable part 240 will be described. The air-cooling duct 250 forms an air flow path 251 through which cooling air flows to cool the protruding part 232 of the cold storage tube 230. The air-cooling duct 250 has an inlet 252 and an outlet 253. The inlet 252 allows the cooling air to flow into the air flow path 251. The outlet 253 allows the cooling air to flow out from the air flow path 251.

[0068] 2, the direction perpendicular to the page is the flow direction of cooling air in air flow path 251. Inlet 252 is provided at the end of air-cooled duct 250 on the front side of the page. Outlet 253 is provided at the end of air-cooled duct 250 on the back side of the page. In FIG. 2, cooling air flows from the front side to the back side of the page.

[0069] In this embodiment, the air-cooled duct 250 has a connection portion 255 and a flow path forming portion 256. The connection portion 255 is a detachable portion that is attached to and detached from the detachable portion 240 of the housing case 210. In this embodiment, the connection portion 255 is formed in a plate shape extending in a direction perpendicular to the top-bottom direction. The top surface of the connection portion 255 in the top-bottom direction is configured to be able to come into contact with the detachable portion 240.

[0070] The flow path forming part 256 forms the air flow path 251 when the connection part 255 is attached to the detachable part 240. The flow path forming part 256 has a bathtub-shaped cross section (in other words, a U-shape). The flow path forming part 256 is disposed so as to cover the multiple protrusions 232.

[0071] The air-cooling duct 250 is formed using, for example, a metal material such as an aluminum-based material or a resin material. As an example, the air-cooling duct 250 of the present embodiment is formed using an aluminum-based material.

[0072] The air-cooling duct 250 may be shared with the airframe structure of the eVTOL 100. The airframe structure may be, for example, the airframe body 110 or the fixed wing 120. The air-cooling duct 250 protects the protruding portion 232 of the regenerator tube 230 from collision with foreign objects, etc.

[0073] Here, the air-cooled duct 250 is attached to the detachable part 240 when the eVTOL 100 is flying, that is, when taking off, cruising, and landing. For this reason, the airflow generated by the flight of the eVTOL 100 flows through the air flow passage 251 in the air-cooled duct 250 as cooling air.

[0074] Hereinafter, a description will be given of the immersion cooling mode in which the immersion cooling device 400 is attached to the detachment part 240. The immersion cooling device 400 is a cooling part that immerses the protruding part 232 of the cold storage tube 230 in a cooling liquid to cool it. As shown in FIG. 3, the immersion cooling device 400 has a cooling tank 410 and a cooling liquid 420.

[0075] The cooling tank 410 constitutes a housing of the immersion cooling device 400. The cooling tank 410 stores a cooling liquid 420, and the protrusion 232 is immersed in the cooling liquid 420.

[0076] The cooling tank 410 has an outer wall surface 411 and an inner wall surface 412, and has a space 413 therein. The cooling tank 410 is formed using, for example, a metal material such as aluminum or a resin material such as CFRP. As an example, the cooling tank 410 of this embodiment is formed using an aluminum material.

[0077] The cooling tank 410 has, for example, a portion on the upper side in the vertical direction configured as a lid portion 414. The lid portion 414 is a detachable portion that is detached from the detachable portion 240 of the storage case 210. In this embodiment, the lid portion 414 is formed in a plate shape that extends vertically in the vertical direction. The lid portion 414 has a cooling tank through hole 415 that communicates with the case through hole 214. The protrusion 232 of the cold storage tube 230 is inserted into the cooling tank through hole 415.

[0078] The cooling liquid 420 is a heat medium that is flowably accommodated in the space 413 of the cooling tank 410. The cooling liquid 420 immerses the protrusions 232 in the cooling tank 410 and absorbs heat from each of the protrusions 232. The cooling liquid 420 is a cooling fluid that cools the protrusions 232. The cooling liquid 420 is a cooling liquid that is at a lower temperature than the flying air.

[0079] For example, water, LLC, etc. can be used as the cooling liquid 420. In this embodiment, as an example, water is used as the cooling liquid 420.

[0080] Another example of the cooling liquid 420 that can be used is a fluorine-based insulating liquid. Examples of the fluorine-based insulating liquid that can be used include Galden (registered trademark) manufactured by Solvay, Asahiklin (registered trademark) manufactured by AGC, and Opteon (registered trademark) manufactured by Chemours.

[0081] Oil can be used as another example of the cooling liquid 420. Oil has low volatility, so there is less leakage from the cooling tank 410 to the outside. In addition, oil is less expensive than the above-mentioned fluorine-based insulating liquid.

[0082] As the oil, for example, SPECTRASYN (registered trademark) from ExxonMobil Corporation, SYNFLUID (registered trademark) from Chevron Phillips Chemical Company, and MIVOLT (registered trademark) from M&I Materials, Inc. In addition, as other oils, for example, AmpCool from Engineered Fluids Corporation and silicone oil from Shin-Etsu Chemical Co., Ltd. can be used.

[0083] A liquid cooling device 500 is connected to the cooling tank 410. The liquid cooling device 500 is a device that cools and stores the cooling liquid 420. In addition, the liquid cooling device 500 is a device that allows the cooling liquid 420 inside the cooling tank 410 to flow in and out by being connected to the cooling tank 410.

[0084] The liquid cooling system 500 includes a tank 510, pipes 520 and 530, a pump 540, and a control device 550. Although not shown, the liquid cooling system 500 also includes a cooling facility for cooling and keeping the cooling liquid 420 in the tank 510 warm.

[0085] The tank 510 is a storage container that stores the cooling liquid 420. The pipes 520 and 530 are connected to the tank 510. The pump 540 pumps the cooling liquid 420 in the tank 510 to the pipe 530.

[0086] The pipes 520 and 530 are, for example, hoses. An upstream end of one pipe 520 and a downstream end of the other pipe 530 are each connected to the cooling tank 410. In this manner, the immersion cooling device 400 and the liquid cooling device 500 are connected via the pipes 520 and 530 to form a cooling circulation circuit 560 in which the cooling liquid 420 can circulate between the immersion cooling device 400 and the liquid cooling device 500.

[0087] The other pipe 530 may be provided with a discharge valve (not shown) for discharging the high-temperature cooling liquid 420 in the cooling tank 410. This allows the high-temperature cooling liquid 420 in the cooling tank 410 to be quickly discharged. Of course, the discharge valve does not have to be provided on the other pipe 530. If the cooling liquid 420 is only circulated in the cooling circulation circuit 560, the discharge valve is not necessary.

[0088] A liquid cooling device 500 is provided for each immersion cooling device 400, for example. Alternatively, a single liquid cooling device 500 may be provided with a plurality of sets of pipes 520, 530 in parallel. In this case, each of the pipes 520, 530 is connected to each of the immersion cooling devices 400.

[0089] The control device 550 is a device that controls the liquid cooling device 500. The control device 550 controls, for example, the rotation speed (pumping capacity) of the pump 540 and the cooling temperature of the cooling equipment. The control device 550 is composed of a well-known microcomputer including a processor, ROM, RAM, etc., and its peripheral circuits. The control device 550 performs various calculations and processes based on a control program stored in the ROM.

[0090] When a plurality of liquid cooling devices 500 are provided, a control device 550 may be provided for each liquid cooling device 500, or a single control device 550 may be used to control the plurality of liquid cooling devices 500.

[0091] As described below, the immersion cooling device 400 is attached to the detachable section 240 after the eVTOL 100 lands. When the eVTOL 100 takes off, cruises, or lands, the immersion cooling device 400 is detached from the detachable section 240 and is located outside the eVTOL 100.

[0092] <Cooling method> Next, a description will be given of a method for cooling each battery cell 220. When the eVTOL 100 is flying, that is, during takeoff, cruising, and landing, an air-cooling duct 250 is attached to the detachable portion 240 of the battery module 200 as shown in FIG.

[0093] The heat of each battery cell 220 is stored in the cold storage material 231 in the cold storage tube 230. This suppresses the temperature rise of each battery cell 220.

[0094] The protruding portion 232 of the cold storage tube 230 is cooled by the blowing wind (i.e., cooling air) flowing through the air flow path 251 of the air-cooling duct 250. As a result, the heat stored in the cold storage material 231 is released to the blowing wind.

[0095] On the other hand, after the eVTOL 100 lands, as shown in Fig. 3, the air-cooling duct 250 is removed from the detachment section 240 of the battery module 200. Then, the immersion cooling device 400 is attached to the detachment section 240. The heat stored in the cold storage material 231 of the cold storage tube 230 is dissipated to the cooling liquid 420 in the cooling tank 410. As a result, the cold storage tube 230 and the battery cells 220 are cooled.

[0096] More specifically, the control device 550 circulates the cooling liquid 420 through the cooling circulation circuit 560 by the pump 540. For example, the low-temperature cooling liquid 420 is caused to flow into the cooling tank 410 through one pipe 530, and the high-temperature cooling liquid 420 is returned to the tank 510 of the liquid cooling device 500 through the other pipe 520. In this case, the pump 540 is controlled to pump the low-temperature cooling liquid 420 through the pipe 530.

[0097] In this manner, by circulating the cooling liquid 420 through the cooling circulation circuit 560, the protrusions 232 disposed inside the cooling tank 410 are rapidly cooled. This rapidly cools the cold storage tubes 230 and the battery cells 220. Furthermore, by previously cooling the cooling liquid 420 using the liquid cooling device 500, the cold storage tubes 230 and the battery cells 220 are cooled even more rapidly.

[0098] <Flight Pattern> Figure 4 shows an example of the most simplified flight pattern from takeoff to landing of the eVTOL 100. Note that the flight patterns of electric flying objects other than the eVTOL 100 are similar to those of the eVTOL 100.

[0099] The period from time T10 to time T11 is referred to as the takeoff period, takeoff time, departure period, departure time, etc. Hereinafter, the period from time T10 to time T11 is referred to as the takeoff time. Takeoff time refers to the ascent in which the eVTOL100 moves from a landed state to a cruising altitude. The period from time T11 to time T12 is referred to as the cruising period, cruising time, etc. The period from time T12 to time T13 is referred to as the landing period, landing time, arrival period, arrival time, etc. Hereinafter, the period from time T12 to time T13 is referred to as the landing time. Landing time refers to the descent of the eVTOL100 from the cruising altitude of the destination to landing on the ground. For convenience, the required power, that is, the output, is constant for each period in FIG. 4.

[0100] The eVTOL 100 ascends from the takeoff point to the altitude of the cruise start point during the period from time T10 to time T11. The eVTOL 100 cruises at a predetermined altitude during the period from time T11 to time T12. The eVTOL 100 descends from the altitude of the end point of time T12 to the landing point during the period from time T12 to time T13.

[0101] The movement of the eVTOL 100 includes mainly horizontal components during cruising, and mainly azimuth components during takeoff and landing. During takeoff and landing, which involve azimuth movement, a higher output is required for driving the rotor 130 of the eVTOL 100 for a certain continuous period of time than during cruising.

[0102] This high output places a large load on the battery cells 220 and EPU 150, which are driving devices for driving the rotors 130. For example, the amount of heat generated by each battery cell 220 increases compared to cruising, causing the temperature to rise. This is because the amount of heat generated by each battery cell 220 is proportional to the output.

[0103] After the eVTOL 100 lands, each battery cell 220 is charged on the ground. When charging of each battery cell 220 is complete, the eVTOL 100 takes off again and begins cruising.

[0104] When the eVTOL 100 is flying (discharging) and on the ground (charging), the battery temperature of each battery cell 220 changes as follows. First, at takeoff, the battery temperature of each battery cell 220 rises rapidly. During cruising, battery output not as high as at takeoff is required, so the battery temperature of each battery cell 220 rises gradually. During landing, battery output similar to that at takeoff is required, so the battery temperature of each battery cell 220 rises rapidly.

[0105] During the flight (discharging) period from time T10 to time T13 when the eVTOL100 takes off and lands, the cold storage material 231 in the cold storage tube 230 stores and cools the heat of the battery cell 220. The protruding portion 232 of the cold storage tube 230 is cooled by the flight wind passing through the air-cooled duct 250, and the cold storage material 231 is cooled.

[0106] This allows each battery cell 220 to be continuously cooled and stored with the cold storage material 231, thereby suppressing an increase in the battery temperature of the battery cells 220. Therefore, at time T13 when the landing of the eVTOL 100 is completed, it is possible to prevent the battery temperature of each battery cell 220 from exceeding the battery allowable temperature.

[0107] The period from time T13 to time T16 is a ground (i.e., charging) period in which each battery cell 220 is charged on the ground and each battery cell 220 is cooled with high efficiency. First, at time T13, the immersion cooling device 400 is attached to the housing case 210 of each battery module 200 of the eVTOL 100. As a result, as described above, the protruding portion 232 of the cold storage tube 230 is cooled by the low-temperature cooling liquid 420, and the temperature of the cold storage tube 230 drops rapidly. Therefore, the battery cell 220 in thermal contact with the cold storage tube 230 is also cooled, and the battery temperature drops rapidly.

[0108] Furthermore, between time T13 and time T14, the bus bar of the battery module 200 is connected to the charging device. When the battery module 200 is connected to the immersion cooling apparatus 400, the bus bar of the battery module 200 may be connected to the charging device at the same time. The charging device may be included in the immersion cooling apparatus 400, or may be independent from the immersion cooling apparatus 400.

[0109] Charging of each battery cell 220 begins from time T14. As a result, each battery cell 220 generates heat, so the drop in battery temperature becomes gradual. When charging of each battery cell 220 is completed at time T15, each battery cell 220 and the bus bar no longer generates heat, so the battery temperature drops rapidly due to cooling by the low-temperature cooling liquid 420. In this way, high-performance cooling of each battery cell 220 is completed at time T16. After time T16, the flight (i.e., discharging) and ground (i.e., charging) from time T10 to time T16 are repeated.

[0110] As described above, in the battery module 200 of this embodiment, the cold storage tube 230 is provided between adjacent battery cells 220. The cold storage tube 230 is provided with a protruding portion 232 that protrudes in one direction from the battery cell 220. The storage case 210 that accommodates the battery cell 220 is provided with a detachable portion 240 to which the immersion cooling device 400 that supplies the cooling liquid 420 to the protruding portion 232 is detachably attached.

[0111] According to this, the cooling method for the protruding portion 232 can be switched simply by attaching and detaching the immersion cooling device 400 to and from the detachment portion 240. By switching the cooling method for the protruding portion 232, it is possible to adjust the cooling performance for the battery cell 220 that is in thermal contact with the cold storage tube 230. Therefore, according to the battery module 200 of this embodiment, it is possible to easily adjust the cooling performance for the battery cell 220.

[0112] More specifically, for example, when the eVTOL 100 is flying, the immersion cooling device 400 is removed from the detachment section 240. Then, the air-cooled duct 250 is attached to the detachment section 240. This allows the heat generated by each battery cell 220 to be absorbed by the cold storage material 231 of the cold storage tube 230, and allows the protrusion 232 of the cold storage tube 230 to be cooled by the flight wind. Therefore, when the eVTOL 100 is flying, the immersion cooling device 400 can be removed to reduce weight, while suppressing the temperature rise of the battery cells 220.

[0113] On the other hand, for example, when the eVTOL 100 is on the ground, it is necessary to cool both the heat stored in the cooling storage material 231 during the flight of the eVTOL 100 and the heat generated by rapid charging of each battery cell 220, so high-performance cooling is required.

[0114] In contrast, in the battery module 200 of this embodiment, an immersion cooling device 400 is attached to the detachment section 240 when the eVTOL 100 is on the ground. This allows the protrusions 232 to be directly immersed in the cooling liquid 420 and cooled, thereby enabling the cold storage material 231 and the battery cells 220 to be cooled with high efficiency.

[0115] Moreover, in the battery module 200 of this embodiment, a safety valve 234 is provided on the protruding portion 232 of the cold storage tube 230. With this, when the internal pressure of the cold storage tube 230 becomes equal to or higher than the reference pressure, the safety valve 234 opens and the cold storage material 231 can be discharged to the outside of the storage case 210. Therefore, even if the internal pressure of the cold storage tube 230 increases due to thermal runaway of the battery cell 220, for example, it is possible to prevent the cold storage tube 230 from breaking and the cold storage material 231 from leaking into the storage case 210, thereby improving safety.

[0116] Second embodiment Next, a second embodiment of the present invention will be described with reference to the drawings. The second embodiment is different from the first embodiment in that a cold air cooling device 600 is used as the cooling unit instead of the immersion cooling device 400.

[0117] In the battery module 200 of this embodiment, a cold air cooling mode is adopted as the ground cooling mode, in which the protrusion 232 is cooled by cold air, which is air that is cooler than the flight air, when the eVTOL 100 is on the ground after landing. Therefore, the battery module 200 of this embodiment is configured to be switchable between the air cooling mode and the cold air cooling mode. The cold air is a gas and corresponds to an example of a cooling fluid.

[0118] 5, in the battery module 200 of the present embodiment, the air-cooling duct 250 is fixed to the housing case 210. As an example, the air-cooling duct 250 is fixed to the outside of the portion of the housing case 210 facing the ground in the top-to-bottom direction. In other words, the air-cooling duct 250 is fixed to the housing case 210 and is not configured to be detachable.

[0119] The air-cooled duct 250 has a cold air cooling device detachment part 254. The cold air cooling device detachment part 254 is a detachment part to which a cold air duct 620 (described later) of the cold air cooling device 600 is detached. As an example, the cold air cooling device detachment part 254 is provided at the inlet 252 of the air-cooled duct 250. The inlet 252 of the air-cooled duct 250 is configured so that the cold air duct 620 can be connected.

[0120] The cold air cooling mode will be described below. The cold air cooling device 600 is a cooling section having a refrigeration cycle device 610 and a cold air duct 620.

[0121] The refrigeration cycle device 610 is configured by connecting a compressor 611, a condenser 612, an expansion valve 613, an evaporator 614, etc. in a ring shape via a refrigerant pipe 615, etc. The compressor 611 compresses and discharges the refrigerant in the refrigeration cycle device 610. The condenser 612 exchanges heat between the high-pressure refrigerant discharged from the compressor 611 and outside air to dissipate heat from the high-pressure refrigerant. The expansion valve 613 reduces the pressure of the refrigerant that has dissipated heat in the condenser 612. The evaporator 614 exchanges heat between the low-pressure refrigerant reduced in pressure by the expansion valve 613 and air blown by a cold air fan 616 to evaporate the low-pressure refrigerant. The cold air fan 616 is an electric blower whose rotation speed (i.e., blowing capacity) is controlled by a control voltage output from a control device (not shown).

[0122] The cold air duct 620 forms a cold air flow path 621 through which the blown air (hereinafter referred to as cold air) cooled by passing through the evaporator 614 flows. The evaporator 614 is disposed in the cold air duct 620. As an example, the evaporator 614 in this embodiment is disposed upstream of the cold air duct 620.

[0123] A cold air outlet 622 of the cold air duct 620 is connected to an inlet 252 of the air-cooled duct 250. A cold air flow path 621 of the cold air duct 620 is connected to an air flow path 251 of the air-cooled duct 250. Therefore, by operating the cold air fan 616, cold air flows into the air flow path 251 of the air-cooled duct 250 via the cold air flow path 621 of the cold air duct 620, and is supplied to the protruding portion 232.

[0124] Next, a description will be given of a method for cooling each battery cell 220 in this embodiment. The method for cooling each battery cell 220 while the eVTOL 100 is flying is the same as in the first embodiment, and therefore a description will be omitted.

[0125] After the eVTOL 100 lands, the cold air duct 620 of the cold air cooling device 600 is attached to the inlet 252 (i.e., the cold air cooling device attachment / detachment part 254) of the air-cooled duct 250 in the battery module 200. Then, cold air cooled by the evaporator 614 of the cold air cooling device 600 flows into the air-cooled duct 250 via the cold air duct 620 and is supplied to the protrusion 232 arranged in the air-cooled duct 250. The heat stored in the cold storage material 231 of the cold storage tube 230 is dissipated to the cold air flowing through the air-cooled duct 250. As a result, each cold storage tube 230 and the battery cells 220 are cooled.

[0126] As described above, in the battery module 200 of this embodiment, the air-cooled duct 250 is provided with a cold air cooling device detachment section 254 to which the cold air duct 620 of the cold air cooling device 600, which supplies cold air cooled by the evaporator 614 of the refrigeration cycle device 610 to the protrusion 232, can be attached and detached.

[0127] According to this, the cooling method for the protrusion 232 can be switched simply by attaching and detaching the cold air cooling device 600 to and from the cold air cooling device attachment / detachment section 254, making it possible to easily adjust the cooling performance for the battery cell 220.

[0128] Third embodiment Next, a third embodiment of the present invention will be described with reference to the drawings. The third embodiment is different from the first embodiment in that it is provided with an air-cooling fan 700. The air-cooling fan 700 is used in an in-flight cooling mode.

[0129] 6, the battery module 200 of this embodiment has an air-cooling fan 700 that blows air into the air-cooling duct 250. The air-cooling fan 700 is an electric blower whose rotation speed (i.e., blowing capacity) is controlled by a control voltage output from a control device (not shown). As an example, the air-cooling fan 700 is disposed outside the inlet 252 of the air-cooling duct 250.

[0130] Next, a description will be given of a method for cooling each battery cell 220 in this embodiment. The method for cooling each battery cell 220 after the eVTOL 100 lands is the same as in the first embodiment, and therefore a description will be omitted.

[0131] When the eVTOL 100 is flying, an air-cooling duct 250 is attached to the attachment / detachment section 240 of the battery module 200. Furthermore, air is blown into the air-cooling duct 250 by an air-cooling fan 700. Heat from each battery cell 220 is stored in the cold storage material 231 in the cold storage tube 230. As a result, each battery cell 220 is cooled.

[0132] The protruding portion 232 of the cold storage tube 230 is cooled by the blown air sent by the air-cooling fan 700. As a result, the heat stored in the cold storage material 231 is dissipated to the blown air.

[0133] As described above, in the battery module 200 of this embodiment, when the eVTOL 100 is flying, the protrusion 232 is cooled by the air blown by the air-cooling fan 700, so that the temperature rise of the battery cell 220 can be more reliably suppressed.

[0134] (Fourth embodiment) Next, a fourth embodiment of the present invention will be described with reference to the drawings. The fourth embodiment is different from the first embodiment in that a heat transfer plate 230A is used as the heat transfer member instead of the cold storage tube 230. Note that the housing case 210, the seal member 215, etc. are not shown in Fig. 7 and Figs. 8 to 13 described later.

[0135] As shown in Fig. 7, in the battery module 200 of this embodiment, a plate-shaped heat transfer plate 230A is provided between adjacent battery cells 220. The heat transfer plate 230A is formed using a metal material such as aluminum. In this embodiment, the heat transfer plate 230A is disposed between adjacent battery cells 220, one at a time. The heat transfer plate 230A and the battery cells 220 are in thermal contact with each other. The heat transfer plate 230A is a heat transfer member that transfers heat between the adjacent battery cells 220.

[0136] Each of the multiple heat transfer plates 230A has a protruding portion 232 that protrudes in at least one direction from the battery cell 220. As an example, the protruding portion 232 protrudes from the multiple battery cells 220 in a direction perpendicular to the cell stacking direction. More specifically, the protruding portion 232 protrudes from the lower surface of the multiple battery cells 220 in the top-to-bottom direction toward the ground.

[0137] As described above, in the battery module 200 of the present embodiment, the heat transfer plate 230A that transfers heat between the adjacent battery cells 220 is provided between the adjacent battery cells 220. With this, the heat of the battery cells 220 is absorbed by the heat transfer plate 230A, so that the battery cells 220 can be cooled.

[0138] Fifth embodiment Next, a fifth embodiment of the present invention will be described with reference to the drawings. The fifth embodiment is different from the first embodiment in the configuration of the cold storage tube 230.

[0139] 8, in the battery module 200 of this embodiment, the cold storage material 231 is filled inside the cold storage tube 230 except for the protruding portion 232. That is, the cold storage material 231 is filled inside the cold storage tube 230 at a portion facing the battery cell 220. In this embodiment, the cold storage material 231 is filled inside the cold storage tube 230 at a portion facing the battery cell 220 via the thermally conductive material 235. Hereinafter, the portion of the cold storage tube 230 except for the protruding portion 232 is referred to as a heat transfer portion 236.

[0140] A filling space 237 filled with a cold storage material 231 is provided inside the heat transfer section 236 of the cold storage tube 230. In this embodiment, a partition section 239 that divides the filling space 237 into a plurality of small spaces 238 is provided inside the heat transfer section 236 of the cold storage tube 230. The cold storage material 231 is filled in each of the plurality of small spaces 238.

[0141] As described above, in the battery module 200 of the present embodiment, the cold storage material 231 is filled inside the cold storage tube 230 except for the protruding portion 232. That is, the cold storage material 231 is not filled inside the protruding portion 232. For this reason, even if the protruding portion 232 corrodes or is damaged in the air-cooling mode or the immersion cooling mode, for example, the cold storage material 231 can be prevented from being released to the outside of the storage case 210.

[0142] Furthermore, in this embodiment, the inside of the cold storage tube 230 is divided into a plurality of small spaces 238, and the cold storage material 231 is filled into each of the plurality of small spaces 238. This makes it possible to prevent the cold storage material 231 from being suddenly released to the outside of the housing case 210 when the cold storage tube 230 corrodes or breaks.

[0143] Sixth embodiment Next, a sixth embodiment of the present invention will be described with reference to the drawings. The sixth embodiment is different from the fifth embodiment in the configuration of the cold storage tube 230. Note that Fig. 9 shows the battery pack 260 as viewed from the sky side in the vertical direction.

[0144] 9, in the battery module 200 of this embodiment, the cold storage tube 230 has protrusions 232 protruding in two directions from the battery cell 220. Here, the direction perpendicular to both the cell stacking direction and the top-bottom direction is referred to as the front-to-back direction. One side in the front-to-back direction is referred to as the front side, and the other side in the front-to-back direction is referred to as the rear side.

[0145] As an example, in this embodiment, the cold storage tube 230 has protrusions 232 protruding forward and backward in the front-rear direction from the multiple battery cells 220. That is, the cold storage tube 230 has a front protrusion 2321 protruding forward from the multiple battery cells 220, and a rear protrusion 2322 protruding rearward from the multiple battery cells 220. The front protrusion 2321 and the rear protrusion 2322 protrude outward from the side surface of the storage case 210.

[0146] The cold storage tube 230 may have a protrusion 232 that protrudes from the battery cell 220 in two directions, toward the sky and toward the ground in the vertical direction.

[0147] As described above, in the battery module 200 of this embodiment, the cold storage tube 230 has the protruding parts 232 protruding in two directions from the battery cells 220, and therefore it is possible to improve the cooling performance for the battery cells 220. In particular, in the air-cooling mode in which the cooling performance is lower than that in the immersion cooling mode, it is possible to effectively improve the cooling performance for the battery cells 220.

[0148] Seventh embodiment Next, a seventh embodiment of the present invention will be described with reference to the drawings. The seventh embodiment is different from the fifth embodiment in the configuration of the cold storage tube 230.

[0149] 10, in the battery module 200 of the present embodiment, the cold storage tube 230 is provided with fins 270. The fins 270 increase the contact area between the fluid around the protruding portion 232 (e.g., cooling air or cooling liquid 420) and the protruding portion 232. The fins 270 are connected to the protruding portion 232.

[0150] The fins 270 are formed using, for example, a metal material. As an example, the fins 270 in this embodiment are formed using the same material as the cold storage tubes 230. The fins 270 may be formed integrally with the cold storage tubes 230.

[0151] The shape of the fin 270 is not particularly limited. As the fin 270, a straight fin having a plate-like portion protruding from the protruding portion 232, a corrugated fin formed by bending a thin plate material into a wave shape, or the like can be used. As an example, as the fin 270 of this embodiment, a straight fin having a plate-like portion protruding from the protruding portion 232 in a direction perpendicular to the top-bottom direction is used.

[0152] As described above, in the battery module 200 of this embodiment, the fins 270 are provided on the cold storage tubes 230, so that the cooling performance for the battery cells 220 can be improved.

[0153] Eighth embodiment Next, an eighth embodiment of the present invention will be described with reference to the drawings. The eighth embodiment is different from the first embodiment in the configuration of the battery pack 260.

[0154] 11, in the battery pack 260 of the present embodiment, either the cold storage tube 230 or the heat transfer plate 230A is disposed between each of the adjacent battery cells 220. The cold storage tubes 230 and the heat transfer plates 230A are disposed alternately in the stacking direction of the cells.

[0155] The cold storage tube 230 has a tube-side protrusion 232 that protrudes in at least one direction from the battery cell 220. The heat transfer plate 230A has a plate-side protrusion 232A that protrudes in at least one direction from the battery cell 220.

[0156] As an example, the tube side protrusion 232 and the plate side protrusion 232A in this embodiment each protrude from the multiple battery cells 220 in a direction perpendicular to the cell stacking direction. More specifically, the tube side protrusion 232 and the plate side protrusion 232A each protrude from the bottom surface of the multiple battery cells 220 in the top-to-bottom direction toward the ground. The tube side protrusion 232 and the plate side protrusion 232A protrude from the battery cell 220 by the same length. Note that the tube side protrusion 232 and the plate side protrusion 232A protrude from the battery cell 220 by different lengths.

[0157] As described above, in the battery module 200 of the present embodiment, the cold storage tubes 230 and the heat transfer plate 230A are provided as heat transfer members for transferring heat to and from the battery cells 220. This makes it possible to achieve both the cold storage and cooling performance of the cold storage tubes 230 and the heat collection and cooling performance of the heat transfer plate 230A.

[0158] Ninth embodiment Next, a ninth embodiment of the present invention will be described with reference to the drawings. The ninth embodiment is different from the eighth embodiment in the configuration of the cold storage tube 230.

[0159] 12, in the battery pack 260 of the present embodiment, the cold storage tube 230 does not have a protruding portion. As an example, the multiple battery cells 220 and the multiple cold storage tubes 230 are arranged so that the positions of the lower surfaces are approximately equal to each other in the top-bottom direction.

[0160] As described above, in the battery module 200 of this embodiment, the plate-side protrusion 232A is provided on the heat transfer plate 230A, and no protrusion is provided on the cold storage tube 230. Therefore, in the case where the cooling performance of the battery cell 220 can be ensured by cooling the plate-side protrusion 232A of the heat transfer plate 230A, it is possible to reduce the filling amount of the cold storage material 231 and to shorten the length of the cold storage tube 230 in the vertical direction.

[0161] Tenth embodiment Next, a tenth embodiment of the present invention will be described with reference to the drawings. The tenth embodiment is different from the first embodiment in that a flat cooling device 800 is used as the cooling section.

[0162] In the battery module 200 of this embodiment, a planar cooling mode is adopted as the ground cooling mode in which the protrusion 232 is cooled by the planar cooling device 800 when the eVTOL 100 is on the ground after landing. Therefore, the battery module 200 of this embodiment is configured to be switchable between the air-cooling mode and the planar cooling mode.

[0163] 13, in the battery module 200 of this embodiment, the protruding portion 232 of the cold storage tube 230 is bent into an L shape. As an example, the protruding portion 232 of this embodiment is formed into an L shape when viewed from the front-rear direction.

[0164] Hereinafter, the lower surface of the protruding portion 232 in the top-bottom direction is referred to as a protruding flat surface 271. The protruding flat surface 271 is formed in a flat shape. As an example, in this embodiment, the protruding flat surfaces 271 of the multiple cold storage tubes 230 are arranged on the same plane.

[0165] The battery module 200 has a cooler detachment part 272. The cooler detachment part 272 is a detachment part to which a flat cooler 830 (described later) of the flat cooling device 800 is detached. In the present embodiment, as an example, the cooler detachment part 272 is provided on a protruding flat surface 271 of the cold storage tube 230. The protruding flat surface 271 of the cold storage tube 230 is configured so that the flat cooler 830 can come into contact with the protruding flat surface 271. The protruding flat surface 271 is configured so that heat can be exchanged between the protruding flat surface 271 and the flat cooler 830.

[0166] The planar cooling mode will be described below. The planar cooling device 800 is a cooling unit having a heat medium circuit 810 that circulates a heat medium. The heat medium is a cooling fluid that cools the protrusion 232 via a planar cooler 830, which will be described later. As an example, in this embodiment, an ethylene glycol aqueous solution is used as the heat medium.

[0167] A heat medium pump 820, a flat cooler 830, a heat medium cooling unit 840, and the like are arranged in the heat medium circuit 810. The heat medium pump 820 is an electric pump that pumps the heat medium circulating through the heat medium circuit 810 to the flat cooler 830. The rotation speed (i.e., heat medium pumping capacity) of the heat medium pump 820 is controlled by a control signal output from a control device (not shown).

[0168] The flat cooler 830 is in thermal contact with the protruding flat surface 271 of the cold storage tube 230. The flat cooler 830 cools the cold storage tube 230 by dissipating heat contained in the cold storage tube 230 to the heat medium.

[0169] The heat medium cooling unit 840 cools the heat medium flowing out from the flat cooler 830. For example, a low-temperature water bath (i.e., a thermostatic bath) maintained at a predetermined cooling temperature can be used as the heat medium cooling unit 840. The cooling temperature is set to a temperature lower than the temperature of the heat medium flowing out from the flat cooler 830, for example.

[0170] Next, a description will be given of a method for cooling each battery cell 220 in this embodiment. The method for cooling each battery cell 220 while the eVTOL 100 is flying is the same as in the first embodiment, and therefore a description will be omitted.

[0171] After the eVTOL 100 lands, the air-cooling duct 250 is removed from the attachment / detachment part 240 of the battery module 200. Then, the planar cooler 830 of the planar cooling device 800 is attached to the cooler attachment / detachment part 272 of the cold storage tube 230. The heat stored in the cold storage material 231 of the cold storage tube 230 is dissipated to the heat medium flowing through the planar cooler 830 via the protruding flat surface 271. As a result, each cold storage tube 230 and the battery cell 220 are cooled.

[0172] As described above, in the battery module 200 of this embodiment, the cooler detachment section 272 to which the planar cooler 830 of the planar cooling device 800 is detached is provided in the regenerator tube 230. With this, the cooling method of the protrusion 232 can be switched simply by attaching and detaching the planar cooling device 800 to and from the cooler detachment section 272, so that the cooling performance for the battery cell 220 can be easily adjusted.

[0173] In the battery module 200 of this embodiment, the protruding portion 232 of the cold storage tube 230 is bent into an L-shape, and the bent plane (i.e., the lower surface of the protruding portion 232 in the top-bottom direction) forms a protruding plane 271. The protruding plane 271 is in thermal contact with the flat cooler 830. This makes it possible to increase the contact area between the cold storage tube 230 and the flat cooler 830 compared to a case where the protruding portion 232 is not bent. As a result, it is possible to improve the heat dissipation performance of the cold storage tube 230 in the flat cooler 830.

[0174] (Other embodiments) The present invention is not limited to the above-described embodiment, and various modifications can be made as follows without departing from the spirit of the present invention.

[0175] (1) For example, in the above-described embodiment, the cooling unit used in the ground cooling mode is the immersion cooling device 400, the cold air cooling device 600, or the planar cooling device 800. However, the cooling unit is not limited to these. For example, a blower fan that blows air to the protrusions 232 and 232A may be used as the cooling unit.

[0176] In this case, the battery module 200 may be configured to be switchable between an air-cooling mode and a fan-cooling mode. The fan-cooling mode is a cooling mode in which the protrusions 232, 232A are cooled by air blown by a blower fan when the eVTOL 100 is on the ground after landing.

[0177] The air-cooled duct 250 may have a fan attachment / detachment section. The fan attachment / detachment section is a section where a blower fan is attached and detached. As an example, the fan attachment / detachment section may be provided at the inlet 252 of the air-cooled duct 250.

[0178] (2) In addition, in the above-described second embodiment, an example has been described in which the cold air cooling device detachment part 254 is provided at the inlet 252 of the air-cooled duct 250, but the arrangement of the cold air cooling device detachment part 254 is not limited to this aspect.

[0179] For example, cold air cooling device attachment / detachment part 254 may be provided in the middle of air-cooled duct 250. The middle of air-cooled duct 250 is a portion between inlet 252 and outlet 253 in air-cooled duct 250. In this case, a through hole may be formed in the middle of air-cooled duct 250, and air flow path 251 of air-cooled duct 250 and cold air flow path 621 of cold air duct 620 may be communicated with each other via the through hole.

[0180] Also, the air-cooling duct 250 may be eliminated, and the cold air cooling device detachable part 254 may be provided in the accommodation case 210. That is, the cold air duct 620 may be detached from the cold air cooling device detachable part 254 provided in the accommodation case 210.

[0181] (3) In addition, in the above-described embodiments except for the sixth embodiment, the protrusion 232 protrudes from the plurality of battery cells 220 toward the ground side, but this is not limited to the embodiment of the protrusion 232. For example, the protrusion 232 may protrude from the plurality of battery cells 220 toward the sky side, or may protrude from the plurality of battery cells 220 toward the front side or the rear side.

[0182] (4) In the above embodiment, an example has been described in which the cold storage tube 230 or the heat transfer plate 230A is provided with the protruding parts 232, 232A protruding in one or two directions from the battery cell 220, but the protruding parts 232, 232A are not limited to this. For example, the cold storage tube 230 or the heat transfer plate 230A may be provided with the protruding parts 232, 232A protruding in three or four directions from the battery cell 220.

[0183] (5) In the above embodiment, the cold storage tube 230 is provided with the safety valve 234, but the present invention is not limited to this. The cold storage tube 230 does not need to be provided with the safety valve 234.

[0184] (6) In the above-described tenth embodiment, the protruding portion 232 of the cold storage tube 230 is bent into an L-shape, and the protruding flat surface 271 is formed by the bent flat surface. However, the shape of the cold storage tube 230 is not limited to this. For example, the cold storage tube 230 may be formed to extend in the vertical direction without being bent, and the protruding flat surface 271 may be formed by the end surface of the cold storage tube 230 on the ground side in the vertical direction.

[0185] The technical features of the battery module disclosed in this specification are as follows: (Item 1) A plurality of stacked battery cells (220); a heat transfer member (230, 230A) disposed between adjacent battery cells, having a protrusion (232, 232A) protruding in at least one direction from the battery cell, and transferring heat between the battery cell and the heat transfer member; a detachable portion (240, 254, 272) to which a cooling portion (400, 600, 800) that supplies a cooling fluid (420) for cooling the protrusion is detached. (Item 2) The cooling unit includes an immersion cooling device (400) that immerses the protrusion in a cooling liquid (420) to cool it, The cooling fluid includes the cooling liquid, The immersion cooling device includes a cooling tank (410) in which the cooling liquid is stored and in which the protrusion is immersed in the cooling liquid; 2. The battery module according to item 1, wherein the cooling tank is configured to be detachable from the detachment section. (Item 3) The cooling section includes a cold air cooling device (600) that supplies cold air cooled by a refrigeration cycle device (610) to the protruding portion, The cooling fluid includes the cold air, 2. The battery module according to item 1, wherein the cool air cooling device is configured to be detachable from the detachment section. (Item 4) The battery module according to item 1 further comprises an air-cooling duct (250) which forms an air flow path (251) through which cooling air flows to cool the protrusion, and which has an inlet (252) for introducing the cooling air into the air flow path, and an outlet (253) for discharging the cooling air from the air flow path. (Item 5) The cooling device further includes an air-cooling duct (250) that forms an air flow path (251) through which cooling air flows to cool the protruding portion, the air-cooling duct having an inlet (252) for introducing the cooling air into the air flow path, and an outlet (253) for discharging the cooling air from the air flow path, 3. The battery module according to item 2, wherein the air-cooling duct and the cooling tank are each configured to be detachable from the detachment section. (Item 6) The cooling device further includes an air-cooling duct (250) that forms an air flow path (251) through which cooling air flows to cool the protruding portion, the air-cooling duct having an inlet (252) for introducing the cooling air into the air flow path, and an outlet (253) for discharging the cooling air from the air flow path, 4. The battery module according to item 3, wherein the attachment / detachment part is provided in the air-cooling duct. (Item 7) The battery pack further includes a housing (210) that houses the plurality of stacked battery cells, 6. The battery module according to any one of items 1 to 5, wherein the casing is provided with the attachment / detachment part. (Item 8) The protrusion protrudes from the housing, The battery module according to item 7, further comprising a seal portion (215) that seals between the housing and the heat transfer member. (Item 9) 9. The battery module according to any one of items 1 to 8, wherein the inside of the heat transfer member is filled with a cold storage material (231). (Item 10) 10. The battery module according to item 9, wherein the cold storage material is filled inside the heat transfer member except for the protruding portion. (Item 11) The battery pack further includes a housing (210) that houses the plurality of stacked battery cells, The protrusion protrudes from the housing, Item 10. The battery module according to item 9, wherein the protruding portion is provided with a safety valve (234) that opens and releases the heat storage material to the outside of the housing when the internal pressure of the heat transfer member becomes equal to or higher than a predetermined reference pressure. (Item 12) Between adjacent battery cells, either a cold storage tube (230) in which a cold storage material (231) is filled inside the heat transfer member or a heat transfer plate (230A) in which the cold storage material is not filled inside the heat transfer member is disposed, the heat transfer member includes the cold storage tube and the heat transfer plate, 9. The battery module according to any one of items 1 to 8, wherein the cold storage tubes and the heat transfer plates are alternately arranged in a stacking direction of the battery cells. (Item 13) The battery module according to any one of items 1 to 12, which is mounted on an electric flying object (100). (Item 14) the cooling unit is attached to the detachable unit when the electric flying vehicle is on the ground after landing, Item 14. The battery module according to item 13, wherein the cooling unit is detached from the detachable unit during flight of the electric flying object. [Explanation of symbols]

[0186] 220 Battery Cell 230 Cold storage tube (heat transfer material) 232 Protrusion 240 Detachment section 400 Immersion cooling device (cooling section)< / evtol>

Claims

1. A plurality of stacked battery cells (220); a heat transfer member (230, 230A) disposed between adjacent battery cells, having a protrusion (232, 232A) protruding in at least one direction from the battery cell, and transferring heat between the battery cell and the heat transfer member; a detachable portion (240, 254, 272) to which a cooling portion (400, 600, 800) that supplies a cooling fluid (420) for cooling the protrusion is detached.

2. The cooling unit includes an immersion cooling device (400) that immerses the protrusion in a cooling liquid (420) to cool it, The cooling fluid includes the cooling liquid, The immersion cooling device includes a cooling tank (410) in which the cooling liquid is stored and in which the protrusion is immersed in the cooling liquid; The battery module according to claim 1 , wherein the cooling tank is configured to be detachable from the detachment portion.

3. The cooling unit includes a cold air cooling device (600) that supplies cold air cooled by a refrigeration cycle device (610) to the protruding portion, The cooling fluid includes the cold air, The battery module according to claim 1 , wherein the cool air cooling device is configured to be detachable from the detachment portion.

4. The battery module of claim 1 further comprising an air-cooling duct (250) that forms an air flow path (251) through which cooling air flows to cool the protrusion, and has an inlet (252) for introducing the cooling air into the air flow path, and an outlet (253) for discharging the cooling air from the air flow path.

5. The cooling device further includes an air-cooling duct (250) that forms an air flow path (251) through which cooling air flows to cool the protrusion, and has an inlet (252) for introducing the cooling air into the air flow path, and an outlet (253) for discharging the cooling air from the air flow path, The battery module according to claim 2 , wherein the air-cooling duct and the cooling tank are each configured to be detachable from the detachment portion.

6. The cooling device further includes an air-cooling duct (250) that forms an air flow path (251) through which cooling air flows to cool the protrusion, and has an inlet (252) for introducing the cooling air into the air flow path, and an outlet (253) for discharging the cooling air from the air flow path, The battery module according to claim 3 , wherein the detachable portion is provided in the air-cooling duct.

7. Further, a housing (210) is provided to house the plurality of stacked battery cells, The battery module according to claim 1 or 2, wherein the detachable portion is provided on the housing.

8. The protrusion protrudes from the housing, The battery module according to claim 7 , further comprising a seal portion (215) for sealing between the housing and the heat transfer member.

9. 3. The battery module according to claim 1, wherein the inside of the heat transfer member is filled with a cold storage material (231).

10. The battery module according to claim 9 , wherein the cold storage material is filled inside the heat transfer member excluding the protruding portion.

11. Further, a housing (210) is provided to house the plurality of stacked battery cells, The protrusion protrudes from the housing, 10. The battery module according to claim 9, wherein the protrusion is provided with a safety valve (234) that opens and releases the heat storage material to the outside of the housing when the internal pressure of the heat transfer member reaches or exceeds a predetermined reference pressure.

12. Between adjacent battery cells, either a cold storage tube (230) in which a cold storage material (231) is filled inside the heat transfer member or a heat transfer plate (230A) in which the cold storage material is not filled inside the heat transfer member is disposed, the heat transfer member includes the cold storage tube and the heat transfer plate, The battery module according to claim 1 , wherein the cold storage tubes and the heat transfer plates are arranged alternately in a stacking direction of the battery cells.

13. The battery module according to claim 1 or 2, which is mounted on an electric flying object (100).

14. the cooling unit is attached to the detachable unit when the electric flying vehicle is on the ground after landing, The battery module according to claim 13 , wherein the cooling unit is detached from the detachable unit when the electric flying object is flying.

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