Temperature control system, temperature control method, and program

Abstract

To prevent overheating while shortening the charging time. [Solution] A temperature control system for managing the battery temperature of a secondary battery using an alkali metal as the negative electrode, comprising a temperature control unit that performs a first control to maintain the battery temperature within a first temperature range during first periods A and C, and a second control to maintain the battery temperature within a second temperature range that is higher than the first temperature range during second periods B and D, in which the amount of charge to the secondary battery is greater than that during the first period. The secondary battery is charged by electricity generated by a solar panel, and the first period is the night period when the solar panel does not generate electricity. The temperature control unit may switch the battery temperature control to the second control in response to the solar panel starting to generate electricity.

Description

Technical Field

[0001] The present invention relates to a temperature management system, a temperature management method, and a program.

Background Art

[0002] Patent Document 1 describes "by setting the charging current to the optimal charging current value at the maximum level that does not cause over-temperature even when a charging current is applied based on the temperature of the secondary battery, shortening the charging time while preventing over-temperature." [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-204800

Summary of the Invention

Means for Solving the Problems

[0003] According to an embodiment of the present invention, a temperature management system for managing the battery temperature of a secondary battery using an alkali metal as a negative electrode is provided. The temperature management system performs a first control to maintain the battery temperature within a first temperature range in a first period, and performs a second control to maintain the battery temperature within a second temperature range having a higher temperature than the first temperature range in a second period in which the amount of charge of the secondary battery is larger than that in the first period. The temperature management system includes a temperature control unit.

[0004] In the temperature management system, the secondary battery may be charged by electric power generated by a solar panel. In any of the temperature management systems, the first period may be a night period when the solar panel does not generate electricity. In any of the temperature management systems, the temperature control unit may switch the control of the battery temperature to the second control in response to the start of power generation by the solar panel. In any of the temperature management systems, the temperature control unit may switch the control of the battery temperature to the first control in response to the stop of power generation by the solar panel.

[0005] Any of the above temperature management systems may include an information acquisition unit that acquires time information including information regarding sunrise time and information regarding sunset time. In the temperature management system, the temperature control unit may switch between the first control and the second control based on the time information acquired by the information acquisition unit.

[0006] In any of the above temperature control systems, the secondary battery may be mounted on an aircraft flying in the stratosphere. In any of the above temperature control systems, the secondary battery may be charged by electricity generated by solar panels on the aircraft. In any of the above temperature control systems, an insulating material may be provided to insulate the secondary battery from the outside air. In any of the above temperature control systems, a heating device may be provided to heat the secondary battery. In any of the above temperature control systems, the insulating material may have insulating performance designed so that the battery temperature does not exceed the upper limit temperature of the first temperature range when the heating device is stopped during the first period. In any of the above temperature control systems, the temperature control unit may perform the first control and the second control by controlling the heating device.

[0007] In any of the above temperature control systems, the upper limit of the second temperature range may be lower than the temperature at which the electrolyte of the secondary battery undergoes thermal decomposition. In any of the above temperature control systems, the second temperature range may be in the range of 30°C to 55°C. In any of the above temperature control systems, the second temperature range may be in the range of 35°C to 45°C. In any of the above temperature control systems, the first temperature range may include 20°C. In any of the above temperature control systems, the first temperature range may be in the range of 15°C to 25°C.

[0008] In any of the above temperature control systems, the secondary battery may be a lithium metal battery.

[0009] According to one embodiment of the present invention, a temperature control method for managing the battery temperature of a secondary battery using an alkali metal as the negative electrode is provided. The temperature control method includes a temperature control step in which, during a first period, a first control is performed to maintain the battery temperature within a first temperature range, and during a second period in which the amount of charge of the secondary battery is greater than that of the first period, a second control is performed to maintain the battery temperature within a second temperature range that is higher than that of the first temperature range.

[0010] According to one embodiment of the present invention, a program is provided for a computer to perform the temperature control method.

[0011] It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. Furthermore, subcombinations of these features may also constitute an invention. [Brief explanation of the drawing]

[0012] [Figure 1] A schematic example of the temperature control system 10 is shown below. [Figure 2] A schematic example of battery temperature control by the temperature control unit 120 is shown below. [Figure 3] A schematic example of battery temperature control by the temperature control unit 120 is shown below. [Figure 4] A schematic example of the temperature control system 10 is shown below. [Figure 5] A schematic example of how the temperature control unit 120 controls the battery temperature when the temperature control system 10 is equipped with a solar panel 400 is shown. [Figure 6] A schematic example of how the temperature control unit 120 controls the battery temperature when the temperature control system 10 is equipped with a solar panel 400 is shown. [Figure 7] A schematic example of the HAPS700 equipped with a temperature control system 10 and a secondary battery unit 200 is shown. [Figure 8] An example of the cycle life test results for secondary battery unit 200 is shown in general terms. [Figure 9]An example of the cycle life test results for secondary battery unit 200 is shown in general terms. [Figure 10] An example of the cycle life test results for secondary battery unit 200 is shown in general terms. [Figure 11] A schematic example of the initial capacity of the secondary battery unit 200 is shown below. [Figure 12] A schematic example of the hardware configuration of a computer 1200 that functions as a temperature control system 10 or temperature control device 100 is shown. [Modes for carrying out the invention]

[0013] The present invention will be described below through embodiments of the invention, but these embodiments are not intended to limit the invention as defined in the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0014] In conventional rechargeable battery environments, temperature control was managed to maintain a constant temperature regardless of day or night. However, rechargeable batteries for HAPS (High Altitude Platform Stations) are required to function normally even in stratospheric environments (temperature: -60 to -90°C, atmospheric pressure: approximately 0.03 atm, ozone concentration: approximately 10 ppm). Furthermore, this must be achieved while minimizing the overall weight and power consumption of the HAPS.

[0015] In a stratospheric environment, if the goal is to maintain a constant temperature for a secondary battery day and night, one approach is to enhance the battery's thermal insulation and then use a cooling device to cool it during daytime temperature increases. In this case, the power consumption of the heating device at night can be reduced, but the overall weight increases due to the need for a cooling device. Alternatively, one could reduce the thermal insulation of the battery and omit a cooling device, instead increasing the output of the heating device during nighttime temperature drops to heat the battery. In this case, the weight of the cooling device can be reduced, but the power consumption of the heating device at night increases.

[0016] The temperature management system 10 according to this embodiment has a configuration that contributes to solving such problems. For example, when a secondary battery is mounted on a HAPS and charged by the electric power generated by a solar panel, the temperature management system 10 maintains the temperature of the secondary battery at a higher level after the daytime charging starts, and maintains the temperature of the secondary battery at a lower level after the charging ends at dusk. Thereby, for example, by eliminating the need for a cooling device, the weight of the entire aircraft can be reduced, and the power consumption of the heating device at night can also be suppressed, and the temperature of the secondary battery can be appropriately managed.

[0017] FIG. 1 schematically shows an example of the temperature management system 10. The temperature management system 10 manages the battery temperature of the secondary battery unit 200. The temperature management system 10 includes a temperature management device 100. The temperature management device 100 includes an information acquisition unit 110 and a temperature control unit 120. The temperature management system 10 may include a heat insulating material 12 that insulates the secondary battery unit 200 from the outside air. The temperature management system 10 may include a temperature control device 14. The temperature management system 10 may include a charging device 300. The charging device 300 may charge the secondary battery unit 200.

[0018] The secondary battery unit 200 has a secondary battery. The secondary battery unit 200 may be the secondary battery itself. The secondary battery unit 200 may have a BMS (Battery Management System). The BMS may monitor the state of the secondary battery and control it so that it can be used safely and for a long time. The BMS may include the temperature management device 100. The secondary battery unit 200 may have a communication device. The secondary battery unit 200 may have various sensors. The sensors included in the secondary battery unit 200 are, for example, a temperature sensor that measures the temperature of the secondary battery, a current sensor that detects charging and discharging of the secondary battery, a pressure sensor that measures the pressure applied to the secondary battery, and the like. These are examples, and the sensors included in the secondary battery unit 200 may include others.

[0019] The secondary battery included in the secondary battery unit 200 is a secondary battery that uses an alkali metal as the negative electrode. The alkali metal may include lithium, sodium, potassium, rubidium, cesium, and francium. The secondary battery may be a lithium metal battery. The secondary battery may be a secondary battery that uses magnesium as the negative electrode. The secondary battery may be a secondary battery that uses an electrolyte solution. The secondary battery may be a secondary battery that uses a solid electrolyte. The secondary battery may be a so-called all-solid-state battery. The secondary battery may be a secondary battery that uses a solid electrolyte and a small amount of liquid electrolyte.

[0020] In the example shown in FIG. 1, the temperature management device 100 is wired-connected to the secondary battery unit 200. The temperature management device 100 may manage the battery temperature by wirelessly communicating with the communication device included in the secondary battery unit 200 using the communication device included in the temperature management device 100.

[0021] The information acquisition unit 110 acquires various types of information. The information acquisition unit 110 may acquire information regarding the operation status of the secondary battery unit 200. The information acquisition unit 110 may acquire information regarding the charging status of the secondary battery unit 200. The information acquisition unit 110 may acquire information regarding the discharging status of the secondary battery unit 200. The information acquisition unit 110 may acquire various types of measurement data acquired by various sensors included in the secondary battery unit 200. For example, the information acquisition unit 110 acquires the battery temperature acquired by the temperature sensor. The information acquisition unit 110 may acquire various types of measurement data acquired by various sensors installed in the environment where the secondary battery unit 200 is installed. For example, the information acquisition unit 110 may acquire the ambient temperature of the secondary battery acquired by the temperature sensor. The ambient temperature may be the outside air temperature.

[0022] The temperature control device 14 may be equipped with a heating function. The heating function can be implemented in any configuration as long as it is possible to heat the secondary battery unit 200. For example, the heating function may be a heating device. The heating device may be, for example, an electric heating wire, a heat pump, a Peltier element, etc. The heating device may be a device that uses a heat transfer medium. The heat transfer medium may be water, oil, air, steam, etc. The heating device may also be a heat pipe.

[0023] The temperature control device 14 may be equipped with a cooling function. The cooling function may be implemented in any configuration as long as it is capable of cooling the secondary battery unit 200. For example, the cooling function may be a cooling device. The cooling device may be, for example, a heat pump, a Peltier element, etc. The cooling device may be a device that uses a heat transfer medium. The cooling device may be a heat pipe. For example, the cooling device may be a variable conductance heat pipe (VCHP).

[0024] The temperature control device 14 may be a heating and cooling device having both a heating function and a cooling function. For example, the temperature control device 14 may be a device having a configuration that heats the secondary battery unit 200 by transmitting a heat source of the temperature control device 14 to a heat medium and circulating the heat medium, and a configuration that cools the secondary battery unit 200 by transmitting a cold source of the temperature control device 14 to a heat medium and circulating the heat medium. In the example shown in Figure 1, the temperature control device 14 has a heat source and a cold source and indirectly heats or cools the secondary battery unit 200 by circulating a heat medium in a tube arranged in contact with the secondary battery unit 200. The temperature control device 14 may separately include a heating device having a heating function and a cooling device having a cooling function. The temperature control device 14 may be equipped with only a heating device. The temperature control device 14 may be equipped with only a cooling device.

[0025] The temperature control unit 120 may control the battery temperature by controlling the temperature control device 14. The temperature control unit 120 may control the temperature control device 14 based on various information acquired by the information acquisition unit 110. For example, the temperature control unit 120 may control the temperature control device 14 based on the current battery temperature of the secondary battery unit 200 acquired by the information acquisition unit 110 to heat or cool the secondary battery unit 200 so as not to exceed a predetermined temperature threshold.

[0026] The thermal insulation material 12 can be made of any material and in any structure, as long as it can insulate the secondary battery unit 200 from the outside air. For example, the thermal insulation material 12 may be made of plastic. For example, the material of the thermal insulation material 12 may be polystyrene, polyurethane, polyimide, phenolic resin, etc. For example, the thermal insulation material 12 may be in the form of a sheet. For example, the thermal insulation material 12 may be in the form of a porous sheet. For example, the thermal insulation material 12 may be foamed plastic. The thermal insulation material 12 may be glass wool, etc. The thermal insulation material 12 may be a vacuum thermal insulation material. For example, a vacuum thermal insulation material may have a structure in which a core material having a porous structure such as glass wool is sealed inside a bag member, and the inside of the bag member is vacuumed. The thermal insulation material 12 may be designed to have a desired thermal insulation performance. For example, the thermal insulation performance of the thermal insulation material 12 may be increased by designing the sheet-shaped thermal insulation material 12 to be thicker, and decreased by designing it to be thinner. The thermal insulation material 12 may have a radiant heat reflective layer. The thermal insulation performance of the thermal insulation material 12 may be designed by adjusting it based on the performance of the radiant heat reflective layer, etc.

[0027] The charging device 300 can be any device that can charge the secondary battery unit 200. For example, the charging device 300 is a power supply that can be connected to the secondary battery unit 200. For example, the charging device 300 is any power generation device that can be connected to the secondary battery unit 200. For example, the charging device 300 is a solar panel.

[0028] Figure 2 schematically shows an example of battery temperature control by the temperature control unit 120. The upper half of Figure 2 shows an example of the time variation of the amount of charge and discharge of the secondary battery. The lower half of Figure 2 shows an example of temperature control of the secondary battery when it is charged and discharged as shown in the upper half of Figure 2. In the lower half of Figure 2, the two thick solid lines represent the upper and lower temperature limits of temperature control by the temperature control unit 120, and the sawtooth-shaped thin solid line represents the battery temperature of the secondary battery. In the example shown in Figure 2, the secondary battery is mainly charged during the day and discharged at night, but the time of day for charging or discharging can be selected depending on the use case of the secondary battery and is not particularly limited.

[0029] The temperature control unit 120 performs a first control to maintain the battery temperature within a first temperature range during a first period. During a second period in which the secondary battery is charged to a greater extent than during the first period, the temperature control unit 120 performs a second control to maintain the battery temperature within a second temperature range that is higher than the first temperature range.

[0030] The first period may be a period in which discharging of the secondary battery is dominant, and the second period may be a period in which charging of the secondary battery is dominant. The secondary battery may not be charged at all during the first period. During the first period, the secondary battery may not be in a charged state, but may be in a discharged state, or in a state where it is neither charging nor discharging (sometimes described as a standby state). During the second period, the secondary battery may be in a charged state, a discharged state, or a standby state. In the example shown in Figure 2, periods A and C are the first period, and periods B and D are the second period. During period B, the secondary battery operates mainly for charging from around 6:00 to around 18:00, but operates for discharging from around 9:00 to around 10:00 and from around 15:00 to around 16:00.

[0031] The first temperature range is, for example, a temperature range from 15°C to 25°C. In this case, the lower limit temperature of the first temperature range is 15°C, and the upper limit temperature of the first temperature range is 25°C. For example, as in the first control, by managing the battery temperature to a relatively low temperature during the period when the secondary battery is mainly discharging, it is possible to improve the cycle life of the charge-discharge cycle of the secondary battery. When the secondary battery is discharging, by managing the battery temperature to 15°C or higher, the internal resistance of the secondary battery can be kept relatively low, and the discharge efficiency can be kept relatively good.

[0032] The temperature control unit 120 may perform the first control for the entire duration of the first period. The temperature control unit 120 may perform the first control for a portion of the duration of the first period. For example, in the example shown in Figure 2, the temperature control unit 120 performs the first control for both period A and period C. The temperature control unit 120 may perform the first control for only one of period A and period C, and not for the other. If the first control is not performed for the first period, the temperature control unit 120 may perform a third control, for example, to maintain the battery temperature within a third temperature range from the lower limit of the first temperature range to the upper limit of the second temperature range. If the first control is not performed for the first period, the temperature control unit 120 may not control the battery temperature.

[0033] The second temperature range is, for example, 25°C to 55°C. For example, by managing the battery temperature to a relatively high temperature during periods when the secondary battery may be charged, as in the second control, it is possible to improve the cycle life of the secondary battery's charge-discharge cycle. When the secondary battery is being charged, managing the battery temperature to 25°C or higher helps maintain a relatively low internal resistance and relatively good charging efficiency. In particular, in the case of a secondary battery using an electrolyte, managing the battery temperature to 55°C or lower when the secondary battery is being charged can suppress the decomposition reaction of the electrolyte in the secondary battery. When gas is generated due to the decomposition of the electrolyte, contact between the electrodes and the electrolyte inside the secondary battery is hindered, making it difficult to secure an ion conduction path, and the charging and discharging of the secondary battery is more likely to stop. In some cases, the casing of the secondary battery may be damaged due to expansion caused by the gas. By suppressing the decomposition reaction of the electrolyte in the secondary battery, these problems can be suppressed.

[0034] The temperature control unit 120 may perform the second control for the entire duration of the second period. The temperature control unit 120 may perform the second control for a portion of the duration of the second period. For example, in the example shown in Figure 2, the temperature control unit 120 performs the second control for both period B and period D. The temperature control unit 120 may perform the second control for only one of period B or period D, and not for the other. If the second control is not performed for the second period, the temperature control unit 120 may perform the third control. If the second control is not performed for the second period, the temperature control unit 120 does not need to control the battery temperature.

[0035] As shown in the example in Figure 2, by roughly setting the first and second periods, the frequency of switching between the first and second temperature ranges of the temperature setpoint is reduced, thus simplifying temperature control by the temperature control unit 120. Furthermore, it becomes easier to make the actual battery temperature track the temperature setpoint. Additionally, if the operating load of the temperature control device 14 can be reduced, power consumption can be suppressed.

[0036] The actual temperature of the secondary battery does not need to track the set temperature controlled by the temperature control unit 120 in real time. For example, the actual temperature of the secondary battery may change gradually to the set temperature over several minutes to several tens of minutes. The actual temperature of the secondary battery does not necessarily need to always be within the temperature range controlled by the temperature control unit 120. For example, there may be periods when the actual temperature of the secondary battery exceeds the upper limit temperature controlled by the temperature control unit 120, and periods when it falls below the lower limit temperature. For example, the average temperature of the secondary battery over a certain period may be within the temperature range controlled by the temperature control unit 120. This is because the actual temperature of the secondary battery depends on the thermal capacity of the secondary battery, the capacity and arrangement of heaters and cooling devices, the manner in which the secondary battery is used, etc., and it may be practically difficult to strictly control the temperature of the secondary battery.

[0037] In this specification, the specific temperature values ​​shown as examples of the first temperature range, the second temperature range, etc., are illustrative, and the specific temperature values ​​for the first temperature range, the second temperature range, etc., may differ from the example temperature values.

[0038] Figure 3 schematically shows an example of battery temperature control by the temperature control unit 120. In the example shown in Figure 3, the differences from Figure 2 will be mainly explained. In the example shown in Figure 3, the first period consists only of the period during which the secondary battery unit 200 is discharged. In the example shown in Figure 3, periods A, C, E, and G are the first period. In the example shown in Figure 3, the second period consists only of the period during which the secondary battery unit 200 is charged. In the example shown in Figure 3, periods B, D, F, and H are the second period. Both the first period and the second period may include a standby period.

[0039] As shown in the example in Figure 3, by precisely setting the first and second periods, the battery temperature is maintained at a high temperature during charging and at a low temperature during discharging, thus further improvement in the cycle life of the secondary battery can be expected. Although the operating load of the temperature control device 14 increases and power consumption may increase due to the increased frequency of switching the temperature setting value, the improved cycle life is beneficial, especially when secondary batteries are expensive.

[0040] Figure 4 schematically shows an example of a temperature control system 10. In the example shown in Figure 4, the differences from Figure 1 will be mainly explained. In the example shown in Figure 4, the temperature control system 10 is equipped with a solar panel 400. The solar panel 400 generates electricity by receiving sunlight 92. The secondary battery may be charged by the electricity generated by the solar panel 400. The information acquisition unit 110 may acquire various measurement data acquired by various sensors installed on the solar panel 400. For example, the information acquisition unit 110 may acquire information on the amount of electricity generated by the electricity generation sensor.

[0041] Figure 5 schematically shows an example of battery temperature control by the temperature control unit 120 when the temperature management system 10 is equipped with a solar panel 400. In the example shown in Figure 5, the differences from Figure 2 will be mainly explained. In the example shown in Figure 5, the first period is the night period when the solar panel 400 does not generate electricity. The second period may be the daytime period when the solar panel 400 generates electricity. The temperature control unit 120 may switch the battery temperature control to the second control in response to the solar panel 400 starting to generate electricity. The temperature control unit 120 may switch the battery temperature control to the first control in response to the solar panel 400 stopping to generate electricity.

[0042] For example, the temperature control device 100 determines whether the solar panel 400 has started generating power based on the power generation amount information acquired by the information acquisition unit 110. For example, the temperature control device 100 determines that the solar panel 400 has started generating power in response to a continuous increase in power generation. For example, the temperature control device 100 determines that the solar panel 400 has started generating power if the power generation amount remains above a predetermined threshold for a predetermined period of time or longer. The temperature control unit 120 may switch the battery temperature control to the second control in response to the determination that the solar panel 400 has started generating power. It is not always necessary for the temperature control device 100 to make an explicit determination. For example, the temperature control unit 120 may switch the battery temperature control to the second control in response to a continuous increase in power generation.

[0043] For example, the temperature control device 100 determines whether the solar panel 400 has stopped generating power based on the power generation amount information acquired by the information acquisition unit 110. For example, the temperature control device 100 determines that the solar panel 400 has stopped generating power in response to a continuous decrease in power generation. For example, the temperature control device 100 determines that the solar panel 400 has started to stop generating power if the power generation amount remains below a predetermined threshold for a predetermined period of time or longer. The temperature control unit 120 may switch the battery temperature control to the first control in response to the determination that the solar panel 400 has stopped generating power. It is not always necessary for the temperature control device 100 to make an explicit determination. For example, the temperature control unit 120 may switch the battery temperature control to the first control in response to a continuous decrease in power generation.

[0044] In the example shown in Figure 5, the temperature control unit 120 switches the temperature control of the battery from the first control to the second control in response to the solar panel 400 starting to generate power around 5 o'clock. The control state before switching the temperature control to the second control is not particularly limited. For example, the temperature control unit 120 may switch the temperature control of the battery from the third control to the second control, or it may switch from a state where the battery temperature is not controlled to the second control.

[0045] In the example shown in Figure 5, the temperature control unit 120 switches the temperature control of the battery from the second control to the first control in response to the solar panel 400 stopping power generation around 19:00. The control state before switching the temperature control to the first control is not particularly limited. For example, the temperature control unit 120 may switch the temperature control of the battery from the third control to the first control, or it may switch from a state where the battery temperature is not controlled to the first control.

[0046] Even during the daytime, the solar panel 400 may temporarily stop generating power if the sunlight 92 received by the solar panel 400 is blocked by an obstruction such as a cloud. In such cases, the temperature control switching conditions may be adjusted so that the temperature control of the battery temperature is not switched to the first control, but rather the second control is maintained. For example, as mentioned above, if the amount of power generated remains below a predetermined threshold for a predetermined period of time or longer, the temperature control unit 120 can determine that the solar panel 400 has stopped generating power, thereby maintaining the second control even if a temporary power generation stop occurs. This makes it less likely for unnecessary control switching to occur, and thus reduces power consumption.

[0047] Figure 6 schematically shows an example of battery temperature control by the temperature control unit 120 when the temperature management system 10 is equipped with a solar panel 400. In the example shown in Figure 6, the differences from Figure 5 will be mainly explained. In the example shown in Figure 6, the information acquisition unit 110 acquires time information including information on sunrise time and information on sunset time. The method by which the information acquisition unit 110 acquires time information is not particularly limited. For example, the information acquisition unit 110 acquires time information from weather forecast information for the area where the secondary battery unit 200 is installed, based on the location information of the area where the secondary battery unit 200 is installed. When the secondary battery unit 200 is installed in HAPS, for example, the information acquisition unit 110 acquires time information based on the location information and altitude information of the area where the HAPS is scheduled to fly. The information acquisition unit 110 may also acquire time information from information held by the HAPS flight simulator.

[0048] The temperature control unit 120 switches between the first control and the second control based on time information. In the example shown in Figure 6, sunrise is at 5:00 and sunset is at 19:00. The temperature control unit 120 switches the temperature control of the battery from the first control to the second control when the current time becomes 5:00, which is sunrise. The temperature control unit 120 switches the temperature control of the battery from the second control to the first control when the current time becomes 19:00, which is sunset.

[0049] Figure 7 schematically shows an example of a HAPS700 equipped with a temperature control system 10 and a secondary battery unit 200. The HAPS700 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 HAPS700 may be an example of an aircraft equipped with a secondary battery whose temperature is controlled by the temperature control system 10 and a thrust generating device that generates thrust using the electrical energy stored in the secondary battery.

[0050] The HAPS700 comprises a fuselage 710, a central section 720, propellers 730, a pod 740, and solar panels 750. The fuselage 710 has wing sections 712. The wing sections 712 include a left wing section 714 and a right wing section 716.

[0051] For example, a secondary battery unit 200 is arranged inside the wing section 712. The electrical energy stored in the secondary battery is utilized by the various components of the HAPS700. For example, the electrical energy stored in the secondary battery is used by the motor of the propeller 730, which generates thrust. As a specific example, multiple secondary batteries connected in parallel are arranged inside the wing section 712. Of the multiple secondary batteries, the left-side batteries may be arranged in the left wing section 714, and the right-side batteries may be arranged in the right wing section 716. The power discharged by the multiple secondary batteries is utilized by the various components of the HAPS700. For example, the power discharged by the multiple secondary batteries is used by the motor of the propeller 730.

[0052] The central section 720 houses the flight control unit 722 and the communication control unit 724. The flight control unit 722 controls the flight of the HAPS700 using power discharged by multiple secondary battery units 200. The communication control unit 724 controls the communication of the HAPS700 using power discharged by multiple secondary batteries.

[0053] The flight control unit 722 controls the flight of the HAPS700, for example, by controlling the rotation of the propeller 730. The flight control unit 722 may also control the flight of the HAPS700 by changing the angles of flaps and elevators (not shown). The flight control unit 722 may be equipped with various sensors such as a GPS sensor, a gyroscope, and an accelerometer to manage the position, direction of movement, and speed of the HAPS700.

[0054] The communication control unit 724 uses an SL (Service Link) 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 the ground-based user terminal 30. The SL antenna may be a multi-beam antenna. The communication area 704 may be a multi-cell.

[0055] The communication control unit 724 may use an 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.

[0056] The communication control unit 724 may communicate with the communication satellite 50 using the satellite communication antenna. The communication control unit 724 may access the network 20 via the communication satellite 50 and the satellite communication station 60.

[0057] The user terminal 30 can be any communication terminal as long as it is capable of communicating with HAPS700. For example, the user terminal 30 may be a mobile phone such as a smartphone. The user terminal 30 may also be a tablet terminal or a PC (Personal Computer). The user terminal 30 may also be a so-called IoT (Internet of Things) device. The user terminal 30 may include anything that falls under the so-called IoE (Internet of Everything).

[0058] The HAPS700 relays communication between the network 20 and the user terminal 30, for example, via a feeder link or a communication satellite 50 and a service link. The HAPS700 may provide wireless communication services to the user terminal 30 by relaying communication between the user terminal 30 and the network 20.

[0059] Network 20 includes a mobile communication network. The mobile communication network may comply with any of the following communication methods: LTE (Long Term Evolution), 5G (5th Generation), 3G (3rd Generation), and 6G (6th Generation) or later. Network 20 may also include the Internet.

[0060] For example, HAPS700 transmits data received from a user terminal 30 within communication area 704 to network 20. Also, for example, if HAPS700 receives data destined for a user terminal 30 within communication area 704 via network 20, it transmits that data to the user terminal 30.

[0061] HAPS700 maintains a communication area 704 in a specific area on the ground while patrolling a predetermined flight path in the stratosphere. HAPS700 maintains stratospheric flight by storing electricity generated by solar panels 750 during the day in multiple secondary batteries, and using the power from these batteries at night. HAPS700 maintains stratospheric flight by, for example, charging multiple secondary batteries during the day while ascending to accumulate potential energy, and then descending slowly at night, using the power from the secondary batteries as needed to operate the propellers 730, etc.

[0062] The management device 800 manages multiple HAPS700s. The management device 800 may communicate with the HAPS700s via the network 20 and the gateway 40. The management device 800 may also communicate with the HAPS700s via the network 20, the satellite communication station 60, and the communication satellite 50.

[0063] The management device 800 controls the HAPS700 by transmitting instructions. The management device 800 may instruct the HAPS700 to orbit above the target area in order to cover the target area on the ground with the communication area 704. For example, while flying in a circular orbit above the target area, the HAPS700 maintains the feeder link with the gateway 40 by adjusting the direction of the FL antenna and maintains coverage of the target area by the communication area 704 by adjusting the direction of the SL antenna.

[0064] The following describes a specific example in which the temperature control system 10 controls the battery temperature of a secondary battery unit 200 when it is mounted on an aircraft flying in the stratosphere. The secondary battery is charged by electricity generated by solar panels 750 on the aircraft. The temperature control system 10 includes an insulating material 12 and a heating device. The insulating material 12 has insulating performance designed so that the battery temperature does not exceed the upper limit temperature of a first temperature range when the heating device is stopped during a first period. The temperature control unit 120 performs first and second control by controlling the heating device.

[0065] The first period may be the nighttime period when the solar panels 750 do not generate electricity. The second period may be the daytime period when the solar panels 750 do generate electricity. Further explanations of the first period, the first temperature range, the first control, the second period, the second temperature range, and the second control are the same as those shown in the examples in Figures 1 to 6. As a result, for example, during the period when the aircraft flies in the stratosphere at night, even if there is heat generated due to the discharge of the secondary battery, the battery temperature will not exceed the upper limit temperature of the first temperature range, so a cooling device is not required at night. For example, during the period when the aircraft flies in the stratosphere during the day, even if there is heat generated due to the charging and discharging of the secondary battery, the upper limit temperature of the second temperature range is relatively high, so a cooling device is not required during the day. In this way, since there is no need to mount a cooling device on the aircraft, it is possible to reduce the overall weight of the aircraft.

[0066] The temperature settings for the first and second temperature ranges in the examples shown in Figures 1 to 7 are described below. The upper limit of the second temperature range may be lower than the temperature at which the electrolyte of the secondary battery decomposes. The temperature at which the electrolyte decomposes may be 60°C or higher. The temperature at which the electrolyte decomposes may be lower by a buffer amount to account for thermal runaway of the secondary battery. The temperature at which the electrolyte decomposes may be 55°C or higher. The temperature at which the electrolyte decomposes may be lower by a buffer amount sufficient to ensure safety, taking into account thermal runaway of the secondary battery. The temperature at which the electrolyte decomposes may be 45°C or higher.

[0067] The lower limit of the second temperature range may be 30°C. By managing the battery temperature to 30°C or higher during secondary battery charging, an improvement in the cycle life of the secondary battery can be expected. The lower limit of the second temperature range may be 35°C. By managing the battery temperature to 35°C or higher during secondary battery charging, a further improvement in the cycle life of the secondary battery can be expected.

[0068] Considering the above temperature characteristics of the secondary battery, the second temperature range may be from 30°C to 55°C. The second temperature range may be from 35°C to 45°C.

[0069] Maintaining a relatively low battery temperature during discharge can improve the cycle life of secondary batteries. The internal resistance of a secondary battery increases as the battery temperature decreases, and the characteristics that change according to the internal resistance of the secondary battery deteriorate. For example, the discharge efficiency of the secondary battery decreases, and the amount of heat generated by the secondary battery increases.

[0070] The upper limit of the first temperature range may be 25°C. By controlling the battery temperature to 25°C or below during the discharge of the secondary battery, an improvement in the cycle life of the secondary battery can be expected.

[0071] The lower limit temperature of the first temperature range may be set considering the internal resistance of the secondary battery. The lower limit temperature of the first temperature range may be set to a low temperature within a range in which the characteristics that change according to the internal resistance of the secondary battery are acceptable.

[0072] The lower limit of the first temperature range may be 15°C. By controlling the battery temperature to 15°C or higher during the discharge of the secondary battery, an improvement in the cycle life of the secondary battery can be expected.

[0073] Considering the above temperature characteristics of the secondary battery, the first temperature range may include 20°C. The first temperature range may be in the range of 15°C to 25°C.

[0074] Figures 8 to 10 schematically show an example of the cycle life test results for a secondary battery unit 200. In the cycle life test, the secondary battery unit 200 was subjected to repeated charge-discharge cycles, and multiple battery characteristics were measured in each cycle. The cycle life was evaluated as the number of cycles at which any of the battery characteristics no longer met a predetermined durability standard. The multiple battery characteristics include, for example, capacity retention rate and internal resistance. In the example shown in Figures 8 to 10, a secondary battery unit 200 having a lithium metal battery with an electrolyte was used. In the example shown in Figures 8 to 10, both the cycle life and the degree of cycle life are shown. More + marks are added when the degree of cycle life is good, and - marks are added when the cycle life is not particularly good.

[0075] In the example shown in Figure 8, to evaluate the temperature dependence of cycle life during charging, the discharge temperature was fixed at 25°C, and the cycle life was evaluated by varying the charging temperature. As a result, when the charging temperature was in the range of 10°C to 55°C, the cycle life was 180 cycles or more. When the charging temperature was in the range of 20°C to 55°C, the cycle life was 200 cycles or more. When the charging temperature was in the range of 35°C to 45°C, the cycle life was 250 cycles or more. Note that when the charging temperature exceeded 55°C, the electrolyte decomposed, and the cycle life decreased significantly.

[0076] When the electrolyte decomposes, its electrical resistance increases. Furthermore, the electrolyte reacts with the negative electrode metal, causing the negative electrode metal to deactivate. Additionally, the decomposition gases cause the battery cell to expand, leading to increased internal resistance and uneven electrochemical reactions. These factors reduce the cycle life. Therefore, when managing the charging temperature at a relatively high level to extend the cycle life, it is advisable to consider these effects when determining the upper temperature limit.

[0077] In the example shown in Figure 9, to evaluate the dependence of cycle life on discharge temperature, the charging temperature was fixed at 25°C, and the cycle life was evaluated by varying the discharge temperature. As a result, when the discharge temperature was in the range of 5°C to 35°C, the cycle life was 180 cycles or more. When the discharge temperature was in the range of 15°C to 25°C, the cycle life was 200 cycles or more. When the discharge temperature was 20°C, the cycle life was 250 cycles or more.

[0078] If the charging temperature is set too low, the electrical resistance of the electrolyte increases. This also leads to unevenness in the electrochemical reaction. As a result, the cycle life decreases. Therefore, when managing the discharge temperature to a relatively low level in order to extend the cycle life, it is advisable to determine the lower limit temperature while considering these effects.

[0079] In the example shown in Figure 10, the cycle life was evaluated when both the charging temperature and the discharging temperature were varied. As a result, when the discharging temperature was 20°C and the charging temperature was in the range of 30°C to 55°C, the cycle life was 300 cycles or more. When the discharging temperature was 20°C and the charging temperature was in the range of 35°C to 45°C, the cycle life was 350 cycles or more.

[0080] When the charging temperature was 40°C and the discharge temperature was in the range of 5°C to 25°C, the cycle life was 250 cycles or more. When the charging temperature was 40°C and the discharge temperature was in the range of 15°C to 25°C, the cycle life was 300 cycles or more. When the charging temperature was 40°C and the discharge temperature was 20°C, the cycle life was 350 cycles or more. From the above, a good cycle life can be expected when the charging temperature is in the range of 35°C to 45°C and the discharge temperature is in the range of 15°C to 25°C.

[0081] Figure 11 schematically shows an example of the initial capacity of the secondary battery unit 200. In Figure 11, the temperature dependence of the initial capacity of the secondary battery unit 200 is shown as a percentage with the initial capacity at 25°C as the reference. In the example shown in Figure 11, the secondary battery unit 200 is a lithium metal battery using an electrolyte.

[0082] When the battery temperature was in the range of -10°C to 15°C, the initial capacity was 90% or more but less than 100%. When the battery temperature was -10°C, the initial capacity was less than 90%. When the battery temperature was in the range of 20°C to 60°C, the initial capacity was 100% or more. From these results, when managing the discharge temperature to a relatively low temperature in order to extend the cycle life, the lower limit temperature may be determined considering the effect of the decrease in initial capacity as described above. For example, if the price of the secondary battery unit 200 is high and lifespan is to be prioritized, the battery temperature during discharge may be managed to a low temperature to the extent that the decrease in initial capacity is limited to about 10%. In this case, for example, the battery temperature during discharge is in the range of -5°C to 15°C. In this case, for example, the battery temperature during discharge is in the range of 0°C to 15°C.

[0083] Figure 12 schematically shows an example of the hardware configuration of a computer 1200 that functions as a temperature control system 10 or a temperature control device 100. A program installed on the computer 1200 can cause the computer 1200 to function as one or more "parts" of the apparatus according to this embodiment, or to cause the computer 1200 to execute operations associated with the apparatus according to this embodiment or such one or more "parts", and / or to cause the computer 1200 to execute a process or a stage of such process according to this embodiment. Such a program may be executed by the CPU 1212 to cause the computer 1200 to execute specific operations associated with some or all of the blocks in the flowcharts and block diagrams described herein.

[0084] The computer 1200 according to this embodiment includes a CPU 1212, RAM 1214, and a graphics controller 1216, which are interconnected by a host controller 1210. The computer 1200 also includes input / output units such as a communication interface 1222, a storage device 1224, a DVD drive, and an IC card drive, which are connected to the host controller 1210 via an input / output controller 1220. The DVD drive may be a DVD-ROM drive and a DVD-RAM drive, etc. The storage device 1224 may be a hard disk drive and a solid-state drive, etc. The computer 1200 also includes legacy input / output units such as a ROM 1230 and a keyboard, which are connected to the input / output controller 1220 via an input / output chip 1240.

[0085] The CPU 1212 operates according to the programs stored in the ROM 1230 and RAM 1214, thereby controlling each unit. The graphics controller 1216 acquires the image data generated by the CPU 1212 and stores it in the frame buffer provided in RAM 1214 or within itself, so that the image data is displayed on the display device 1218.

[0086] The communication interface 1222 communicates with other electronic devices via a network. The storage device 1224 stores programs and data used by the CPU 1212 in the computer 1200. The DVD drive reads programs or data from a DVD-ROM or the like and provides them to the storage device 1224. The IC card drive reads programs and data from an IC card and / or writes programs and data to an IC card.

[0087] The ROM 1230 stores boot programs and / or hardware-dependent programs of the computer 1200, which are executed by the computer 1200 upon activation. The input / output chip 1240 may also connect various input / output units to the input / output controller 1220 via USB ports, parallel ports, serial ports, keyboard ports, mouse ports, etc.

[0088] The program is provided on a computer-readable storage medium such as a DVD-ROM or IC card. The program is read from the computer-readable storage medium and installed on a storage device 1224, RAM 1214, or ROM 1230, which are examples of computer-readable storage media, and executed by the CPU 1212. The information processing described within these programs is read by the computer 1200, resulting in coordination between the program and the various types of hardware resources described above. The apparatus or method may be configured to realize the operation or processing of information in accordance with the use of the computer 1200.

[0089] For example, when communication is performed between a computer 1200 and an external device, the CPU 1212 may execute a communication program loaded into RAM 1214 and, based on the processing described in the communication program, instruct the communication interface 1222 to perform communication processing. Under the control of the CPU 1212, the communication interface 1222 reads transmission data stored in a transmission buffer area provided in a recording medium such as RAM 1214, storage device 1224, DVD-ROM, or IC card, transmits the read transmission data to the network, or writes received data received from the network to a reception buffer area provided on the recording medium.

[0090] Furthermore, the CPU 1212 may read all or necessary parts of a file or database stored on an external recording medium such as the storage device 1224, a DVD drive (DVD-ROM), or an IC card into the RAM 1214, and perform various types of processing on the data in the RAM 1214. The CPU 1212 may then write the processed data back to the external recording medium.

[0091] Various types of information, such as various types of programs, data, tables, and databases, may be stored on the recording medium and subjected to information processing. The CPU 1212 may perform various types of processing on the data read from RAM 1214, including various types of operations, information processing, conditional judgments, conditional branching, unconditional branching, information retrieval / replacement, etc., as described throughout this disclosure and specified by the program instruction sequence, and write the results back to RAM 1214. The CPU 1212 may also retrieve information in files, databases, etc., within the recording medium. For example, if multiple entries are stored in the recording medium, each having an attribute value of a first attribute associated with an attribute value of a second attribute, the CPU 1212 may search among the multiple entries for an entry that matches the specified condition for the attribute value of the first attribute, read the attribute value of the second attribute stored in that entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies the predetermined condition.

[0092] The program or software module described above may be stored on or near the computer 1200 in a computer-readable storage medium. Alternatively, a recording medium such as a hard disk or RAM provided within a server system connected to a dedicated communication network or the Internet can be used as a computer-readable storage medium, thereby providing the program to the computer 1200 via the network.

[0093] In this embodiment, blocks in the flowchart and block diagram may represent a stage in a process in which an operation is performed or a "part" of a device that has the role of performing an operation. A particular stage and "part" may be implemented by a dedicated circuit, a programmable circuit supplied with computer-readable instructions stored on a computer-readable storage medium, and / or a processor supplied with computer-readable instructions stored on a computer-readable storage medium. The dedicated circuit may include digital and / or analog hardware circuits, and may include integrated circuits (ICs) and / or discrete circuits. The programmable circuit may include reconfigurable hardware circuits, such as field-programmable gate arrays (FPGAs) and programmable logic arrays (PLAs), which include logical AND, logical OR, exclusive OR, negated AND, negated OR, and other logical operations, flip-flops, registers, and memory elements.

[0094] A computer-readable storage medium may include any tangible device capable of storing instructions that can be executed by a suitable device, and as a result, a computer-readable storage medium having instructions stored therein will comprise a product that includes instructions that can be executed to create means for performing operations specified in a flowchart or block diagram. Examples of computer-readable storage media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, etc. More specific examples of computer-readable storage media may include floppy disks, diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), electrically erasable programmable read-only memory (EEPROM), static random access memory (SRAM), compact disk read-only memory (CD-ROM), digital multipurpose disc (DVD), Blu-ray® disc, memory stick, integrated circuit card, etc.

[0095] Computer-readable instructions may include assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk®, Java®, C++, and traditional procedural programming languages ​​such as the C programming language or similar programming languages.

[0096] Computer-readable instructions may be provided locally or via a wide area network (WAN) such as a local area network (LAN) or the internet to a processor or programmable circuit of a general-purpose computer, special-purpose computer, or other programmable data processing device, so that the processor or programmable circuit of the programmable data processing device, such as a computer, can execute the instructions to generate means for performing operations specified in a flowchart or block diagram. Here, the computer may be a PC (personal computer), tablet computer, smartphone, workstation, server computer, general-purpose computer, or special-purpose computer, and may also be a computer system in which multiple computers are connected. Such a computer system in which multiple computers are connected is also called a distributed computing system and is a computer in a broad sense. In a distributed computing system, multiple computers execute a program collectively by each computer executing a part of the program and passing data during program execution between computers as needed.

[0097] Examples of processors include computer processors, central processing units, processing units, microprocessors, digital signal processors, controllers, and microcontrollers. A computer may have one or more processors. In a multiprocessor system with multiple processors, each processor executes a portion of the program, and the processors collectively execute the program by passing program execution data between them as needed. For example, in the execution of multitasks, each of the multiple processors may execute a portion of each task in small chunks by switching tasks at each time slice. In this case, which part of a program each processor executes changes dynamically. Which part of a program each of the multiple processors executes may also be statically determined by multiprocessor-aware programming.

[0098] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0099] It should be noted that the execution order of operations, procedures, steps, and stages in the apparatus, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before" or "prior to," and that these can be implemented in any order unless the output of a previous process is used in a later process. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," and "next," for convenience, this does not mean that it is essential to perform the operations in that order. [Explanation of Symbols]

[0100] 10 Temperature management system, 12 Insulation material, 14 Temperature control device, 20 Network, 30 User terminal, 40 Gateway, 50 Communication satellite, 60 Satellite communication station, 92 Solar power, 100 Temperature control device, 110 Information acquisition unit, 120 Temperature control unit, 200 Secondary battery unit, 300 Charging device, 400 Solar panel, 700 HAPS, 702 Beam, 704 Communication area, 710 Airframe, 712 Wing section, 714 Left wing section, 716 Right wing section, 720 Center section, 722 Flight control unit, 724 Communication control unit, 730 Propeller, 740 Pod, 750 Solar panel, 800 Management device, 1200 Computer, 1210 Host controller, 1212 CPU, 1214 RAM, 1216 Graphics controller, 1218 Display device, 1220 Input / output controller, 1222 communication interface, 1224 storage device, 1230 ROM, 1240 input / output chip

Claims

1. A temperature control system for managing the battery temperature of a secondary battery that uses metallic lithium as the negative electrode, A temperature control unit performs a first control to maintain the battery temperature within a first temperature range during a first period, and a second control to maintain the battery temperature within a second temperature range that is higher than the first temperature range during a second period in which the secondary battery is charged more than during the first period. Equipped with, The aforementioned secondary battery is mounted on an aircraft flying in the stratosphere and is charged by electricity generated by solar panels on the aircraft. The aforementioned temperature control system is The aforementioned secondary battery is insulated from the outside air by an insulating material, A heating device for heating the secondary battery and Equipped with, The thermal insulation material has thermal insulation performance designed so that the battery temperature does not exceed the upper limit temperature of the first temperature range when the heating device is stopped during the first period. The temperature control unit performs the first control and the second control by controlling the heating device, thereby providing a temperature control system.

2. The aforementioned secondary battery is charged by the electricity generated by the solar panel, The first period is the nighttime period when the solar panels do not generate electricity. The temperature control unit switches the control of the battery temperature to the second control in response to the state in which the amount of power generated by the solar panel is above a predetermined threshold for a predetermined period of time or longer, as described in claim 1.

3. The aforementioned secondary battery is charged by the electricity generated by the solar panel, The first period is the nighttime period when the solar panels do not generate electricity. The temperature control unit switches the control of the battery temperature to the first control in response to the fact that the amount of power generated by the solar panel remains below a predetermined threshold for a predetermined period of time or longer, as described in claim 1.

4. The aforementioned secondary battery is charged by the electricity generated by the solar panel, The first period is the nighttime period when the solar panels do not generate electricity. The temperature control unit switches the control of the battery temperature to the second control in response to the solar panel starting to generate power, according to claim 1.

5. The temperature control unit switches the control of the battery temperature to the first control in response to the solar panel ceasing to generate power, according to claim 4.

6. The aforementioned secondary battery is charged by the electricity generated by the solar panel, The temperature management system includes an information acquisition unit that acquires time information including information regarding sunrise time and information regarding sunset time. The temperature control unit switches between the first control and the second control based on the time information acquired by the information acquisition unit, according to claim 1.

7. The temperature control system according to any one of claims 1 to 6, wherein the upper limit temperature of the second temperature range is lower than the temperature at which the electrolyte of the secondary battery undergoes thermal decomposition.

8. The temperature control system according to any one of claims 1 to 6, wherein the second temperature range is in the range of 30°C to 55°C.

9. The temperature control system according to claim 8, wherein the second temperature range is in the range of 35°C to 45°C.

10. The temperature control system according to any one of claims 1 to 6, wherein the first temperature range includes 20°C.

11. The temperature control system according to claim 10, wherein the first temperature range is in the range of 15°C to 25°C.

12. A temperature control method performed by a temperature control system that manages the battery temperature of a secondary battery using metallic lithium as the negative electrode, A temperature control step in which, during a first period, a first control is performed to maintain the battery temperature within a first temperature range, and during a second period in which the amount of charge of the secondary battery is greater than that of the first period, a second control is performed to maintain the battery temperature within a second temperature range that is higher than the first temperature range. Equipped with, The aforementioned secondary battery is mounted on an aircraft flying in the stratosphere and is charged by electricity generated by solar panels on the aircraft. The aforementioned temperature control system is The aforementioned secondary battery is insulated from the outside air by an insulating material, A heating device for heating the secondary battery and Equipped with, The thermal insulation material has thermal insulation performance designed so that the battery temperature does not exceed the upper limit temperature of the first temperature range when the heating device is stopped during the first period. The temperature control step is a temperature control method that performs the first control and the second control by controlling the heating device.

13. A program for causing a computer to perform the temperature control method described in claim 12.

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