Temperature control device for secondary batteries, temperature control method for secondary batteries, and computer program

Abstract

By suppressing changes in battery temperature, the degradation of battery capacity is suppressed. [Solution] The temperature control device comprises a housing for housing a secondary battery, a heat transfer medium filled in the housing, a cooling unit positioned vertically above the housing, a state quantity acquisition unit that acquires state quantities including the temperature of the secondary battery, the charge level, and the current flowing through the secondary battery, a vapor pressure acquisition unit that acquires the vapor pressure of the heat transfer medium, a resistance determination unit that determines the electrical resistance of the secondary battery using map data relating the electrical resistance of the secondary battery to the state quantities and the acquired state quantities, an output calculation unit that calculates a heat output by correcting the amount of heat generated by the secondary battery calculated using the determined electrical resistance of the secondary battery using the acquired vapor pressure of the heat transfer medium, and an output control unit that controls the cooling unit so that the calculated heat output and the cooling output of the cooling unit cooling the inside of the housing are the same.

Description

[Technical Field]

[0001] The present invention relates to a temperature control device for a secondary battery, a temperature control method for a secondary battery, and a computer program. [Background technology]

[0002] Secondary batteries used as batteries for electric vehicles and the like are well known (see, for example, Patent Document 1). In the secondary battery described in Patent Document 1, each of the multiple battery modules (secondary batteries) is connected to a heat sink via a heat pipe. Cooling water passages are formed inside the heat sink through which cooling water, cooled by a radiator, flows. Therefore, secondary batteries that heat up during charging and discharging are cooled by the heat sink through which cooling water flows. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-204151 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] In the liquid-cooled cooling method described in Patent Document 1, which uses a liquid to transfer heat, the specific heat of water as the heat transfer medium is high, resulting in high cooling capacity. However, because water has a high sensible heat, the amount of heat required to cool or heat the water is large. In the air-cooled method, which uses a gas as the heat transfer medium, the specific heat of the gas is low, resulting in low heat transport capacity. Also, in the air-cooled method, exhaust heat loss is high. In vapor heat transport, a cooling method different from liquid-cooled and air-cooled methods, the battery is cooled by the latent heat of vaporization of a low-boiling-point medium that has a boiling point lower than the heat-generating temperature of the secondary battery. The vaporized low-boiling-point medium is cooled by the cooling unit and liquefied, and the secondary battery is cooled again. In vapor heat transport, the battery temperature is maintained at the boiling point of the low-boiling-point medium by balancing the heat generation of the secondary battery with the cooling of the cooler. However, if the secondary battery is discharged until the State of Charge (SOC), which represents the charge state, becomes low, or if charging is started from a low SOC range, the heat generated due to the reaction resistance of the electrodes may exceed the cooling output of the cooler, potentially causing the battery temperature to rise. When the battery temperature rises, the electrical resistance of the secondary battery decreases, and when the battery temperature falls, the electrical resistance of the secondary battery increases. In other words, the electrical resistance of the secondary battery changes depending on the battery temperature and SOC. Therefore, the secondary battery may not be able to be properly cooled due to the changing electrical resistance, and there was a risk that the capacity of the secondary battery would deteriorate.

[0005] This invention was made to solve at least some of the above-mentioned problems, and aims to suppress battery capacity degradation by suppressing changes in battery temperature. [Means for solving the problem]

[0006] The present invention has been made to solve at least some of the above-mentioned problems and can be realized in the following forms.

[0007] (1) According to one embodiment of the present invention, a temperature control device for a secondary battery is provided. This temperature control device comprises: a housing for housing the secondary battery; a heat transfer medium filled in the housing for which the liquid and substrate change according to the temperature; a cooling unit positioned vertically above the housing for cooling the inside of the housing; a state quantity acquisition unit for acquiring state quantities including the temperature of the secondary battery, the charge level of the secondary battery, and the current flowing through the secondary battery; a vapor pressure acquisition unit for acquiring the vapor pressure of the heat transfer medium; a resistance determination unit for determining the electrical resistance of the secondary battery using pre-created map data relating the electrical resistance of the secondary battery to the state quantities and the state quantities acquired by the state quantity acquisition unit; an output calculation unit for calculating the amount of heat generated by the secondary battery using the electrical resistance of the secondary battery determined by the resistance determination unit, and for calculating the heat output of the secondary battery by correcting the calculated amount of heat generated using the vapor pressure of the heat transfer medium acquired by the vapor pressure acquisition unit; and an output control unit for controlling the cooling unit so that the calculated corrected heat output of the secondary battery and the cooling output of the cooling unit for cooling the inside of the housing are the same.

[0008] In this configuration, the secondary battery, which generates heat during charging and discharging, is cooled by vapor heat transport using the latent heat of the heat transfer medium filled in the housing. The heat transfer medium, which has vaporized after cooling the secondary battery, moves vertically upward through the space in the housing and is cooled and condensed by the cooling unit. The condensed liquid heat transfer medium cools the secondary battery again. Vapor heat transport cools the battery more efficiently compared to liquid cooling methods. The electrical resistance of the secondary battery changes according to the state variables of the secondary battery. In this configuration, the electrical resistance of the secondary battery is determined by using the acquired state variables of the secondary battery against pre-created map data. The amount of heat generated by the secondary battery, calculated using the determined electrical resistance of the secondary battery, is calculated as the heat output of the secondary battery, corrected for the amount of heat generated by disturbances using the vapor pressure of the heat transfer medium. The cooling output is controlled to match the corrected heat output of the secondary battery, thereby cooling the secondary battery appropriately. As a result, the accuracy of estimating the heat output of the secondary battery during charging and discharging is improved compared to cases where the electrical resistance of the secondary battery is not estimated. Therefore, the temperature difference and temperature change between the highest and lowest temperatures of the secondary battery are suppressed over time. This suppresses the progression of capacity degradation in the secondary battery.

[0009] (2) In the temperature control device according to the above embodiment, a heating unit is further provided which is arranged vertically below the housing unit and heats the inside of the housing unit, and the output control unit may control the cooling unit so that the cooling output of the cooling unit is equal to the sum of the heat output of the heating unit, which is determined by the temperature difference between the set temperature of the heating unit and the temperature inside the housing unit, and the heat output of the secondary battery after correction. In this configuration, the heat transfer medium within the housing is heated by a heating element positioned vertically below the secondary battery. When liquid heat transfer medium is present vertically below the housing, the heating element vaporizes the liquid heat transfer medium. This increases the circulation flow rate of the heat transfer medium within the housing, thereby increasing the cooling output. As a result, the secondary battery is sufficiently cooled even during high-rate charging and discharging.

[0010] (3) In the temperature control device according to the above embodiment, the cooling unit has a refrigerant flow path forming unit located vertically above the housing unit and forming a first refrigerant flow path through which the refrigerant flows, and a refrigerant pump that controls the flow rate of the refrigerant flowing through the first refrigerant flow path, the heating unit has a heat medium flow path forming unit located vertically below the housing unit and forming a first heat medium flow path through which the heat medium flows, and a heat medium pump that controls the flow rate of the heat medium flowing through the first heat medium flow path, the temperature control device further comprises an evaporator through which a first heat exchange medium that cools the refrigerant by performing heat exchange with the refrigerant flows, a first compression unit that compresses the first heat exchange medium discharged from the evaporator, a condenser to which the first heat exchange medium discharged from the first compression unit is supplied and which heats the heat medium by performing heat exchange between the first heat exchange medium and the heat medium, and a first expansion unit that expands the first heat exchange medium discharged from the condenser and supplies it to the evaporator, and the output control unit may control the cooling output of the cooling unit by controlling the evaporator and the refrigerant pump. In this configuration, the heat transfer medium in the containment section is cooled by the refrigerant flowing through the first refrigerant channel in the cooling section and heated by the heat transfer medium flowing through the first heat transfer medium channel in the heating section. The refrigerant is cooled in the evaporator via the first heat exchange medium. The heat transfer medium is heated in the condenser via the first heat exchange medium. With this configuration, since the containment section is not directly cooled or heated using the first heat exchange medium, water or other fluids with high specific heat and cooling capacity can be used as the refrigerant and heat transfer medium.

[0011] (4) In the temperature control device according to the above embodiment, the cooling unit has a cooling unit side flow path forming unit which is located vertically above the housing unit and forms a second refrigerant flow path through which the second heat exchange medium flows, the heating unit has a heating unit side flow path forming unit which is located vertically below the housing unit and forms a second heat medium flow path through which the second heat exchange medium flows, the temperature control device further comprises a second compression unit which compresses the second heat exchange medium discharged from the second refrigerant flow path and supplies it to the second heat medium flow path, a heat dissipation unit which dissipates heat from the second heat medium flow path, and a second expansion unit which expands the second heat exchange medium discharged from the heat dissipation unit and supplies it to the second refrigerant flow path, and the output control unit may control the cooling output of the cooling unit by controlling the second compression unit. In this configuration, the second heat exchange medium, which is heated by the heat dissipation section and expanded to low temperature and low pressure by the second compression section, flows through the second refrigerant flow path of the cooling section, thereby cooling the heat medium vertically above within the containment section. On the other hand, the second heat exchange medium, which is compressed to high temperature and high pressure by the second compression section, flows through the second heat medium flow path, thereby heating the vertically below within the containment section. In other words, since one type of second heat exchange medium performs both cooling and heating within the containment section, the configuration of the temperature control device in this configuration is simplified.

[0012] (5) In the temperature control device according to the above embodiment, the output control unit may set a lower limit temperature of the secondary battery using the ratio of the amount of heat generated by the secondary battery before correction to the amount of heat generated by the heating unit, the upper limit of the cooling output of the cooling unit, and the minimum settable temperature of the cooling unit, and set an upper limit temperature of the secondary battery using the ratio of the amount of heat generated, the upper limit of the cooling output of the cooling unit, and the maximum settable temperature of the heating unit, and control the cooling output of the cooling unit so that the temperature of the secondary battery during charging and discharging is above the lower limit temperature and below the upper limit temperature. In this configuration, the upper limit of the secondary battery's control temperature during charging and discharging is set from the upper limit of the cooling unit's output capacity. On the other hand, the lower limit of the secondary battery's control temperature during charging and discharging is set from the lower limit of the heating unit's output capacity. In other words, the control temperature range of the secondary battery is set using the maximum cooling output of the cooling unit and the maximum heat output of the heating unit. As a result, the secondary battery's temperature during charging and discharging does not exceed the control temperature range, and the progression of capacity degradation of the secondary battery is suppressed.

[0013] (6) In the temperature control device of the above embodiment, the output control unit may calculate the temperature during charging and discharging of the secondary battery at which the sum of degradation components, which is the sum of a high-temperature degradation component whose degradation rate coefficient increases as the temperature of the secondary battery increases and a low-temperature degradation component whose degradation rate coefficient increases as the temperature of the secondary battery decreases, is minimized. The output control unit may calculate the lower temperature and the higher temperature of the sum of degradation components corresponding to the temperature during charging and discharging of the secondary battery obtained by multiplying the calculated temperature during charging and discharging of the secondary battery by a predetermined coefficient of 1 or more, and control the cooling output of the cooling unit so that the temperature during charging and discharging of the secondary battery is greater than or equal to the calculated lower temperature and less than or equal to the calculated higher temperature. In this configuration, the control temperature range of the secondary battery is calculated using a predetermined coefficient, based on the charging and discharging temperature at which the sum of degradation components is minimized. With this configuration, the temperature range is determined by setting a predetermined coefficient, based on the temperature at which capacity degradation is most suppressed. In other words, by setting a desired predetermined coefficient, it becomes possible to set a temperature control range that suppresses the capacity degradation of the secondary battery.

[0014] (7) In the temperature control device of the above embodiment, the output control unit calculates a switching time which is the charge-discharge time of the secondary battery at which the slope of the capacity degradation amount with respect to the charge-discharge time, calculated from the charge-discharge time of the secondary battery and the capacity degradation amount after charge-discharge, is the same as the slope of the tangent to the square root of the charge-discharge time of the secondary battery. Until the charge-discharge time of the secondary battery reaches the switching time, the cooling output of the cooling unit may be controlled using the predetermined coefficient. After the switch time, the cooling output of the cooling unit may be controlled so that the temperature of the secondary battery is above the lower of the two temperatures calculated using a coefficient larger than the predetermined coefficient and below the higher of the two temperatures. In this configuration, based on the calculated switching time, the temperature of the secondary battery during charging and discharging is controlled within a wide temperature control range calculated by a coefficient larger than a predetermined coefficient after the switching time. The capacity degradation of a secondary battery increases significantly in the initial stages of use and then slows down. In this configuration, the switching time at which the capacity degradation slows down is calculated, and the temperature of the secondary battery is controlled within a wider temperature range than in the initial stages of use after the switching time. As a result, after the switching time, the target temperature for cooling a high-temperature secondary battery and the target temperature for heating a low-temperature secondary battery are relaxed, so that the energy required to reach the target temperature is suppressed, and the capacity degradation of the secondary battery is suppressed.

[0015] (8) The temperature control device according to the above embodiment may further include an update unit that updates the map data using the amount of change in the electrical resistance of the secondary battery calculated using the charge / discharge time of the secondary battery and the average value of the state variables, and the amount of change in electrical resistance calculated using the time of the secondary battery when it is not being charged or discharged and the average value of the state variables. In this configuration, pre-created map data is updated using the state variables and charge / discharge times during charging and discharging of the secondary battery, as well as the state variables and charge / discharge times when the secondary battery is not in use. The capacity degradation of the secondary battery progresses even when it is not in use, other than during charging and discharging. Furthermore, the electrical resistance of the secondary battery during charging and discharging, obtained from the map data, changes depending on the degree of capacity degradation and the usage status of the secondary battery. In this configuration, the map data is updated according to the charge / discharge time and the time the secondary battery is not in use, thus improving the accuracy of estimating the electrical resistance of the secondary battery. As a result, the accuracy of estimating the corrected heat output of the secondary battery improves, further suppressing the progression of capacity degradation of the secondary battery.

[0016] Furthermore, the present invention can be realized in various forms, for example, as a temperature control device for a secondary battery, a cooling device for a secondary battery, a secondary battery system, an electric vehicle, a method for controlling the temperature of a secondary battery, a method for cooling a secondary battery, and a system equipped with these devices, a computer program for executing these devices, a server device for distributing this computer program, and a non-temporary storage medium storing the computer program. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic block diagram of the temperature control system for a secondary battery according to the first embodiment. [Figure 2] This diagram illustrates the relationship between battery capacity and voltage when the discharge state of a secondary battery is changed. [Figure 3] This is an explanatory diagram showing how the electrical resistance of a secondary battery changes according to its State of Charge (SOC). [Figure 4] This is a schematic block diagram of the thermal circuit in the cooling section, heating section, and secondary battery. [Figure 5] This is a flowchart of the temperature control method for a secondary battery according to the first embodiment. [Figure 6] This shows the time course of the battery temperature controlled by the temperature control system of the first embodiment. [Figure 7]This shows the time course of the battery temperature controlled by the temperature control system in the comparative example. [Figure 8] This is a schematic block diagram of the temperature control system for a secondary battery according to the second embodiment. [Figure 9] This is an explanatory diagram of the rate coefficient of degradation due to electrical conduction. [Figure 10] This diagram illustrates the relationship between the amount of capacity degradation, the degradation rate coefficient, and time in a secondary battery. [Figure 11] This is an explanatory diagram of the control temperature range of the secondary battery before and after the switching time. [Figure 12] This diagram illustrates the changes in the upper and lower limits of the secondary battery's control temperature before and after the switching time. [Figure 13] This is a schematic block diagram of the temperature control system for a secondary battery according to the fourth embodiment. [Figure 14] This is an explanatory diagram illustrating the relationship between the state variables of a secondary battery and the ratio of the increase in electrical resistance. [Figure 15] This is a flowchart of the temperature control method for a secondary battery in the fourth embodiment. [Figure 16] This is a flowchart of the temperature control method for a secondary battery in the fourth embodiment. [Modes for carrying out the invention]

[0018] <First Embodiment> Figure 1 is a schematic block diagram of a temperature control system (temperature control device) 100 of a secondary battery BT as one embodiment of the present invention. The temperature control system 100 cools a plurality of secondary batteries BT housed in a case (housing section) 40 by vapor heat transport utilizing the latent heat of a fluorocarbon-based medium (heat transfer medium) 45 filled in the case 40. In this embodiment, the electrical resistance of the secondary batteries BT is determined by using state quantities such as the current flowing through the secondary batteries BT during charging and discharging against pre-created map data. Using the determined electrical resistance, the corrected heat output of the secondary batteries based on the amount of heat generated by the secondary batteries BT is calculated, and the same cooling output as the calculated heat output is output by the cooling section 50.

[0019] As shown in Figure 1, the temperature control system 100 includes a control device 30, a plurality of secondary batteries BT, a case 40 housing the plurality of secondary batteries BT, a fluorocarbon-based medium 45 filled inside the case 40, a cooling unit 50 positioned vertically above the case 40, a heating unit 60 positioned vertically below the case 40, a temperature sensor SS1 for detecting the temperature of the secondary batteries BT, a charge rate sensor SS2 for detecting the State of Charge (SOC) representing the charge rate of the secondary batteries, a current sensor SS3 for detecting the current flowing through the secondary batteries BT during charging and discharging, a pressure sensor SS4 for detecting the vapor pressure of the fluorocarbon-based medium 45 inside the case 40, an evaporator 70, a condenser 80, a compressor (first compression unit) C1, and an expansion valve (first expansion unit) E1.

[0020] The cooling unit 50 includes a refrigerant flow path forming unit 51 that forms a refrigerant flow path (first refrigerant flow path) 52 through which the refrigerant 53 flows, and a refrigerant pump P1 that circulates the refrigerant 53 within the refrigerant flow path 52. The refrigerant flow path forming unit 51 is positioned vertically above the case 40, as shown in Figure 1. The heating unit 60 includes a heat medium flow path forming unit 61 that forms a heat medium flow path (first heat medium flow path) 62 through which the heat medium 63 flows, and a heat medium pump P2 that circulates the heat medium 63 within the heat medium flow path 62. In this embodiment, an electrically insulating LLC (long-life coolant), such as ethylene glycol, is used as the refrigerant 53 and heat medium 63.

[0021] The evaporator 70 and the condenser 80 are connected by a first flow path FP1. A heat exchange medium (first heat exchange medium) HE1 circulates within the first flow path FP1. As shown in Figure 1, a compressor C1 and an expansion valve E1 are located on the first flow path FP1. The compressor C1 is a compressor that compresses the heat exchange medium HE1 discharged from the evaporator 70. The compressor C1 is positioned on the first flow path FP1 to supply the compressed heat exchange medium HE1 to the condenser 80. Therefore, the condenser 80 is supplied with heat exchange medium HE1 that has been compressed to high temperature and pressure. The condenser 80 performs heat exchange between the heat exchange medium HE1 flowing through the first flow path FP1 and the heat medium 63 flowing through the heat medium flow path 62. The heat medium 63 is heated by heat exchange with the heat exchange medium HE1 that has been compressed to high temperature and pressure.

[0022] The expansion valve E2 expands the heat exchange medium HE1 discharged from the condenser 80. The expansion valve E1 is positioned on the first flow path FP1 to supply the expanded heat exchange medium HE1 to the evaporator 70. Therefore, the evaporator 70 is supplied with heat exchange medium HE1 that has expanded to a low temperature and low pressure. The evaporator 70 performs heat exchange between the heat exchange medium HE1 flowing through the first flow path FP1 and the refrigerant 53 flowing through the refrigerant flow path 52. The refrigerant 53 is cooled by heat exchange with the heat exchange medium HE1 that has expanded to a low temperature and low pressure.

[0023] The control device 30 shown in Figure 1 is a so-called personal computer. The control device 30 comprises a CPU (Central Processing Unit) 10 and a memory device called a map database (map DB) 20. The map DB 20 stores map data that associates the electrical resistance of the secondary battery BT during charging and discharging with the state variables of the secondary battery BT. The state variables of the secondary battery BT are values ​​that change according to the state of the secondary battery BT, including the temperature of the secondary battery BT during charging and discharging, the state of charge (SOC) of the secondary battery BT, and the current flowing through the secondary battery BT. The map data is pre-created data obtained by measuring the state variables using the secondary battery BT under various conditions.

[0024] Figures 2 and 3 are explanatory diagrams of the map data. Figure 2 shows the change in voltage value of a secondary battery BT under temperature control at 20 degrees Celsius (°C). This change in voltage value corresponds to the change in battery capacity (Ah) when the discharge state changes. Figure 3 shows the change in electrical resistance of the secondary battery BT according to the State of Charge (SOC) of the secondary battery BT. Specifically, in Figure 2, the voltage change for 0.1C discharge is shown by curve C0.1 (thin solid line), the voltage change for 1C discharge is shown by curve C1.0 (dashed line), the voltage change for 2C discharge is shown by curve C2.0 (dotted line), and the voltage change for 3C discharge is shown by C3.0 (solid line). As shown in each curve in Figure 3, the voltage value, and thus the electrical resistance of the secondary battery BT, changes according to the discharge state and battery capacity.

[0025] Figure 3 shows an example of map data created from the voltage change of the secondary battery BT shown in Figure 2. The map data for estimating the electrical resistance of the secondary battery BT in this embodiment is obtained from the State of Charge (SOC) of the secondary battery BT, the temperature of the secondary battery BT, and the voltage value shown in Figure 2, as shown in Figure 3. The electrical resistance of the secondary battery BT is calculated by dividing the voltage difference ΔV for different discharge states (e.g., 0.1C and 1C) shown in Figure 2 by the current flowing through the secondary battery BT, assuming that the resistance changes linearly. The current is calculated by the product of the C rate and the battery capacity (Ah). Therefore, by inputting the SOC of the secondary battery BT during charging and discharging, the temperature of the secondary battery BT, and the current value of the secondary battery BT into the created map data, the electrical resistance of the secondary battery BT during charging and discharging is determined. An example of the map data shown in Figure 3 is the curves C15, C20, and C30, which represent the electrical resistance that changes according to the temperature and SOC of the secondary battery BT. The solid curve C15 represents the electrical resistance when the temperature of the secondary battery BT is 15°C. The dashed curve C20 represents the electrical resistance when the secondary battery BT is at a temperature of 20°C. The dashed-dotted curve C30 represents the electrical resistance when the secondary battery BT is at a temperature of 30°C.

[0026] The CPU 10 shown in Figure 1 is connected to a ROM (Read Only Memory) and RAM (Random Access Memory) (not shown), and controls various parts of the temperature control system 100 by loading the computer program stored in the ROM into the RAM and executing it. In addition, as shown in Figure 1, the CPU 10 functions as an acquisition unit 11, a correction unit 12, a resistance determination unit 13, an output calculation unit 14, and an output control unit 15.

[0027] The acquisition unit 11 acquires the state quantities of the secondary battery BT during charge and discharge detected by three sensors SS1 to SS3. Further, the acquisition unit 11 acquires the vapor pressure of the fluorocarbon-based medium 45 in the case 40 detected by the pressure sensor SS4. The resistance determination unit 13 determines the electrical resistance of the secondary battery BT during charge and discharge by using the state quantities of the secondary battery BT detected by the sensors SS1 to SS3 with respect to the map data stored in the map DB20. The output calculation unit 14 calculates the calorific value generated by the secondary battery BT itself by using the determined electrical resistance of the secondary battery BT.

[0028] The correction unit 12 calculates, as a correction value, the calorific value generated by components other than the secondary battery BT by using the vapor pressure of the fluorocarbon-based medium 45 acquired by the pressure sensor SS4. The heat generation output of the entire case 40 cooled by the cooling unit 50 includes the calorific value generated by disturbances such as heat dissipation from the outer periphery and abnormal heat generation. Therefore, in the present embodiment, the correction unit 12 calculates the calorific value to be added as a correction value to the calorific value generated by the secondary battery BT itself by using the vapor pressure deviation calculated from the detected vapor pressure of the fluorocarbon-based medium 45. The output calculation unit 14 calculates the corrected heat generation output (calorific value Q batt ), which is the sum of the calorific value ΔQ batt calculated as the correction value and the calorific value Q b calculated for the secondary battery BT itself.

[0029] The corrected calorific value Q b , which is the calorific value of the entire case 40 to which the correction value is added, is expressed by the following formula (2) as the sum of the calorific value Q batt generated by the secondary battery BT itself and the calorific value ΔQ batt generated by disturbances. The calorific value Q batt of the secondary battery BT is calculated by using the electrical resistance determined from the map data.

Equation

[0030] The calorific value ΔQ batt generated by disturbances is related to the vapor pressure P sIt is expressed as shown in the following equation (3). The correction unit 12 substitutes the above equation (1) and the following equation (3) into the above equation (2) to obtain the corrected heat generation Q of the secondary battery BT. b Calculate.

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[0031] The output calculation unit 14 calculates the corrected heat generation amount Q. b The temperature of the cooling unit 50 is calculated to produce the same cooling output. Figure 4 is a schematic block diagram of the thermal circuit in the cooling unit 50, heating unit 60, and secondary battery BT. In Figure 4, the cooling unit 50, heating unit 60, secondary battery BT, which are heat sources, and the thermal resistance between each component are shown as a modeled thermal circuit. As shown in Figure 4, the temperature change ΔT of the cooling unit 50 c And the temperature change ΔT of the heating section 60 h And the temperature change ΔT of the secondary battery BT b The relationship shown in equation (4) below holds true. Note that K in equation (4) is the heat transfer coefficient (W / (m 2 ·K)) represents the heat transfer area (m²). 2 ) represents. The subscripts K and A represent the following: "c" represents the cooling unit 50, "h" represents the heating unit 60, "b" represents the secondary battery BT, and "r" represents the required value.

number

[0032] The vapor temperature T through which the fluorocarbon medium 45 flows inside case 40 sThis can be expressed as shown in equation (5) below. And the corrected heat output Q in equation (5) b This can be expressed as shown in equation (2) above. Therefore, from equations (2), (4), and (5), the battery temperature T of the secondary battery BT can be expressed. b And, steam temperature T s Each of these can be expressed as shown in equations (6) and (7) below.

number

[0033] Heat generation Q of the heating element 60 h And the corrected heat generation amount Q b Therefore, if the bottom heating ratio (heating ratio) x is defined as shown in equation (8) below, the temperature T of the heating section 60 h And, battery temperature T b The following equation (9) holds between the two. Therefore, the temperature T of the heating section 60 h This is expressed as shown in equation (10) below. Note that the bottom heating ratio x is the corrected heat output Q. b Q is the amount of heat generated by heating the heating section 60. h This corresponds to the ratio of . By substituting the above equation (5) into equation (10), the temperature T of the heating section 60 can be obtained. h This can be expressed as shown in equation (11) below.

number

[0034] Substituting equation (11) above into equation (6) above yields equation (12). Equation (12) is given by the battery temperature T b The temperature T of the cooling section 50 c and corrected heat generation Q b This indicates that the bottom heating ratio x and the minimum temperature T that the cooling unit 50 can set are determined by the bottom heating ratio x and the bottom heating ratio x. c Using this, the battery temperature T b Set the lower temperature limit.

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[0035] From equations (4) and (8) above, equation (13) below holds true, so the temperature T of the cooling unit 50 c This can be expressed as shown in equation (14) below. Also, the steam temperature T in equation (14) s By substituting equation (5) above into the given equation, we derive equation (15) below.

[0036]

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[0037] By substituting equations (5) and (14) into equation (6) above, equation (16) is derived. Equation (16) is given by the battery temperature T b The temperature of the heating section 60 T h and corrected heat generation Q b This indicates that the bottom heating ratio x and the maximum temperature T that the heating unit 60 can set are determined by the bottom heating ratio x and the bottom heating ratio x. h Using this, the battery temperature T b Set the upper limit temperature.

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[0038] From the above, the temperature T of the cooling unit 50 c This is the lower limit temperature that can be set, and the temperature of the heating section 60 T h When the maximum temperature that can be set is reached, the battery temperature T b However, if the relationship shown in equation (17) below, derived using the above equations (1), (12), and (16), is satisfied, then cooling of the secondary battery BT can be achieved under the heat source constraints of the cooling unit 50 and the heating unit 60. In other words, in this embodiment, the output control unit 15 controls the battery temperature T of the secondary battery BT. b The control is performed within the range that satisfies the following equation (17).

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[0039] The output calculation unit 14 shown in Figure 1 calculates the corrected heat generation Q. bThe same cooling output is calculated. Note that if there is heating by the heating unit 60, the output calculation unit 14 calculates the corrected heat generation amount Q. b and the amount of heat generated by the heating element Q h The cooling output is calculated to be the same as the sum of the heating output and the cooling output. The output calculation unit 14 calculates the corrected heat output Q in the above formula (15). b By substituting this value, the temperature T of the cooling unit 50 to be set can be determined. c The output control unit 15 calculates the temperature T of the cooling unit 50. c The evaporator 70 is controlled to achieve the following result.

[0040] Furthermore, the output control unit 15 controls the temperature T of the cooling unit 50. c In addition, the required circulation flow rate V of refrigerant 53 c,r This is calculated using the following formula (18). The output control unit 15 determines the required circulation flow rate V of the calculated refrigerant 53. c,r The refrigerant pump P1 is controlled so that the refrigerant circulates within the refrigerant flow path 52. The temperature change ΔT of the cooling section 50 in equation (18) c This is calculated using equation (19) below, which is derived from equation (14) above. ΔT in equation (18) L (K) represents the allowable value of the temperature difference between the inlet and outlet of the refrigerant 53. In this embodiment, the temperature difference between the inlet and outlet of the refrigerant 53 is ΔT L This is set to approximately 2-3K, that is, within a range that ensures uniformity.

number

[0041] Figure 5 is a flowchart of the temperature control method for the secondary battery BT in this embodiment. In the temperature control flow shown in Figure 5, charging and discharging of the secondary battery BT is started first (step S1). Next, a state quantity acquisition process is performed in which three sensors SS1 to SS3 acquire the state quantities of the secondary battery BT (step S2). The state quantities of the secondary battery BT include the temperature of the secondary battery BT detected by the temperature sensor SS1, the state of charge (SOC) of the secondary battery BT detected by the charge level sensor SS2, and the current flowing through the secondary battery BT detected by the current sensor SS3. In addition, the pressure sensor SS4 performs a vapor pressure acquisition process to acquire the vapor pressure of the fluorocarbon medium 45 inside the case 40 (step S3).

[0042] Next, the correction unit 12 calculates the amount of heat generated by disturbances ΔQ in equation (2) above as a correction value. batt This is calculated by substituting the detected vapor pressure of the fluorocarbon medium 45 into the above equation (3) (step S4). The resistance determination unit 13 uses the detected state quantities of the secondary battery BT with respect to the map data stored in the map DB 20 to determine the electrical resistance R of the secondary battery BT during charging and discharging. batt A resistance determination process is performed to determine the value (step S5).

[0043] The output calculation unit 14 calculates the amount of heat generated by the disturbance ΔQ. batt The electrical resistance R of the secondary battery BT was determined to be R. batt Using this, the corrected heat output Q is the total heat output for Case 40. b The output calculation process is performed to calculate the electrical resistance R of the secondary battery BT determined for the above formula (1) (step S6). The output calculation unit 14 calculates the electrical resistance R of the secondary battery BT determined for the above formula (1). batt By using this method, the heat generated Q from the secondary battery BT itself can be reduced. batt The output calculation unit 14 calculates the amount of heat generated by the secondary battery BT, as shown in equation (2) above. batt And the amount of heat generated by the secondary battery BT after correcting for the sum with the disturbances Q. b It is calculated as follows.

[0044] The output control unit 15 calculates the corrected heat generation amount Q. bUsing the above formula (15), the desired temperature T of the cooling unit 50 is calculated. c The calculated temperature T is calculated (step S7). The output control unit 15 then outputs the calculated temperature T c The evaporator 70 is controlled to achieve this (step S8). The output control unit 15 uses the above equations (18) and (19) to determine the required circulation flow rate V of the refrigerant 53. c,r The output control unit 15 calculates the required circulation flow rate V (step S9). c,r The refrigerant pump P1 is controlled to achieve this (step S10). The process from step S7 to step S10 corresponds to the output control process.

[0045] Subsequently, it is determined whether or not to terminate the charging and discharging process (step S11). The determination of whether or not to terminate the charging and discharging process is made when an input unit (not shown in Figure 1) receives user input, or when either charging or discharging is completed up to the target State of Charge (SOC). If it is determined that the charging and discharging process will not be terminated (step S11: NO), the process from step S2 onwards is repeated. If it is determined that the charging and discharging process will be terminated (step S11: YES), the temperature control flow of the secondary battery BT is terminated.

[0046] Figure 6 shows the battery temperature T controlled by the temperature control system 100 of this embodiment. b This shows the time progression. Figure 6 shows the battery temperature T at multiple locations in multiple secondary batteries BT housed in case 40 during discharge of 3C. b Of these, curve Cc1 (solid line) representing the lowest temperature trend and curve Ch1 (dashed line) representing the highest temperature trend are shown. In the example shown in Figure 6, the battery temperature T measured at multiple locations is shown. b The average value was controlled to be 31°C. In this case, the temperature of the refrigerant 53 discharged from the evaporator 70 was controlled to be within the range of 20-25°C. As a result, the battery temperature T at multiple locations was controlled. b The temperature difference between the highest and lowest temperatures after discharge was 5.4°C.

[0047] Figure 7 shows the battery temperature T controlled by the comparative example's temperature control system. bThis shows the time progression. Figure 7 shows the temperature progression when a constant 15°C refrigerant 53 is continuously supplied without temperature control of the refrigerant 53, compared to the control of this embodiment shown in Figure 6. The solid curve Cc2 represents the lowest temperature progression in the comparative example. The dashed curve Ch2 represents the highest temperature progression in the comparative example. As shown in Figure 7, in the comparative example, the battery temperature T at multiple locations b The temperature difference between the highest and lowest temperatures after discharge was 20°C, which is much larger than the 5.4°C in this embodiment.

[0048] As described above, the temperature control system 100 of this embodiment includes a control device 30, a plurality of secondary batteries BT, a case 40 housing the plurality of secondary batteries BT, a fluorocarbon-based medium 45 filled in the case 40, a cooling unit 50 positioned vertically above the case 40, a temperature sensor SS1 for detecting the temperature of the secondary batteries BT, a charge rate sensor SS2 for detecting the State of Charge (SOC) representing the charge rate of the secondary batteries, a current sensor SS3 for detecting the current flowing through the secondary batteries BT during charging and discharging, and a pressure sensor SS4 for detecting the vapor pressure of the fluorocarbon-based medium 45 in the case 40. The resistance determination unit 13 determines the electrical resistance of the secondary batteries BT during charging and discharging by using the state quantities of the secondary batteries BT detected by sensors SS1 to SS3 against the map data stored in the map DB 20. The correction unit 12 calculates the amount of heat to be added as a correction value to the amount of heat generated by the secondary batteries BT themselves using the vapor pressure deviation calculated from the detected vapor pressure of the fluorocarbon-based medium 45. The output calculation unit 14 calculates the amount of heat ΔQ as the correction value. batt And the calculated heat generation Q of the secondary battery BT itself. batt The corrected heat output (heat output Q) is the sum of the two. bis calculated using the above formula (2). In this embodiment, the secondary battery BT that generates heat during charging and discharging is cooled by vapor heat transport using the latent heat of the fluorocarbon-based medium 45 filled in the case 40. The fluorocarbon-based medium 45 that vaporizes by cooling the secondary battery BT moves vertically upward in the space within the case 40 and is cooled and condensed by the cooling unit 50. The condensed liquid fluorocarbon-based medium 45 cools the secondary battery BT again. By vapor heat transport, the secondary battery BT is cooled more efficiently compared to the liquid cooling method. The electrical resistance of the secondary battery BT changes according to the state quantity of the secondary battery BT. In this embodiment, the electrical resistance of the secondary battery BT during charging and discharging is determined by using the acquired state quantity of the secondary battery BT for the pre-created map data. The heat generation amount Q of the secondary battery calculated using the determined electrical resistance of the secondary battery BT batt is the heat generation amount ΔQ due to disturbance using the vapor pressure of the fluorocarbon-based medium 45 batt and is calculated as the heat generation amount Q of the secondary battery BT corrected by that amount b The cooling output by the cooling unit 50 is controlled so that it becomes the same as the heat generation amount Q of the corrected secondary battery BT b so that the secondary battery BT is appropriately cooled. As a result, the estimation accuracy of the heat generation output of the secondary battery BT during charging and discharging is improved compared to the case where the electrical resistance of the secondary battery BT is not estimated. Therefore, the temperature difference and temperature change between the maximum temperature and the minimum temperature are suppressed in the time transition of the temperature T b of the secondary battery BT. Thereby, the progress of capacity degradation of the secondary battery BT is suppressed.

[0049] Further, when there is heating by the heating unit 60, the output calculation unit 14 of this embodiment uses the corrected heat generation amount Q b and the heat generation amount Q by the heating unit hCalculate the cooling output that is the same as the heat generation output of the sum with [it]. In the present embodiment, the heating unit 60 disposed vertically below the secondary battery BT heats the fluorocarbon-based medium 45 in the case 40. When there is a liquid fluorocarbon-based medium 45 on the vertically lower side in the case 40, the liquid fluorocarbon-based medium 45 vaporizes due to the heating by the heating unit 60. As a result, since the circulation flow rate of the fluorocarbon-based medium 45 in the case 40 increases, the cooling output increases. As a result, even during charging and discharging of the high-rate secondary battery BT, the secondary battery BT is sufficiently cooled.

[0050] Further, the evaporator 70 of the present embodiment performs heat exchange between the heat exchange medium HE1 flowing in the first flow path FP1 and the refrigerant 53 flowing in the refrigerant flow path 52. The refrigerant 53 is cooled by heat exchange with the heat exchange medium HE1 expanded to low temperature and low pressure. Further, the condenser 80 performs heat exchange between the heat exchange medium HE1 flowing in the first flow path FP1 and the heat medium 63 flowing in the heat medium flow path 62. The heat medium 63 is heated by heat exchange with the heat exchange medium HE1 compressed to high temperature and high pressure. In the present embodiment, the fluorocarbon-based medium 45 in the case 40 is cooled by the refrigerant 53 flowing in the refrigerant flow path 52 of the cooling unit 50 and heated by the heat medium 63 flowing in the heat medium flow path 62 of the heating unit 60. That is, since the inside of the case 40 is not directly cooled and heated using the heat exchange medium HE1, water or the like having a large fluid specific heat and high cooling capacity can be used as the refrigerant 53 and the heat medium 63.

[0051] Further, in the present embodiment, the calorific value Q of the heating unit 60 h and the corrected calorific value Q b From this, the bottom surface heating ratio x is defined as in the above formula (8). The output control unit 15 uses the bottom surface heating ratio x and the minimum temperature T c that can be set by the cooling unit 50 to set the lower limit temperature of the battery temperature T b . From this, the output control unit 15 uses the bottom surface heating ratio x and the maximum temperature T h that can be set by the heating unit 60 to set the upper limit temperature of the battery temperature T b . And the output control unit 15 controls the battery temperature T of the secondary battery BT bThe temperature is controlled within the range of the upper and lower temperature limits, that is, within the range that satisfies equation (17) above. In this embodiment, the maximum cooling output of the cooling unit 50 and the maximum heat output of the heating unit 60 are used to set the control temperature range of the secondary battery BT as shown in equation (17) above. Therefore, the battery temperature T of the secondary battery BT during charging and discharging b The degradation of the secondary battery BT's capacity is suppressed without exceeding the controlled temperature range.

[0052] <Second Embodiment> Figure 8 is a schematic block diagram of the temperature control system 100a of the secondary battery BT according to the second embodiment. In the first embodiment, the refrigerant 53 flowing through the cooling section 50 and the heat transfer medium 63 flowing through the heating section 60 are different heat exchange media, and the refrigerant 53 and heat transfer medium 63 are cooled or heated by heat exchange with the heat exchange medium HE1. In contrast, in the second embodiment, the heat exchange medium (second heat exchange medium) HE2 flowing through the cooling section 50a and the heating section 60a is the same. The heat exchange medium HE2 in the second embodiment is compressed by the compressor (second compression section) C2, heat is dissipated by the radiator (heat dissipation section) 90, and expansion is performed by the expansion valve (second expansion section) E2. Therefore, in the second embodiment, the explanation of the same configuration and shape as in the first embodiment is omitted, and the explanation of the configuration and shape that differ from the first embodiment is given.

[0053] The temperature control system 100a shown in Figure 8 comprises a control device 30a, a plurality of secondary batteries BT, a case 40, a fluorocarbon-based medium 45, a cooling unit 50a, a heating unit 60a, three sensors SS1 to SS3 for detecting the state of the secondary batteries BT, a pressure sensor SS4, a compressor C2, a heat sink 90, and an expansion valve E2.

[0054] The cooling section 50a of the second embodiment includes a cooling section side flow path forming section 51a that forms a cooling section side flow path (second refrigerant flow path) 52a through which the heat exchange medium HE2 flows. The heating section 60a includes a heating section side flow path forming section 61a that forms a heating section side flow path (second heat medium flow path) 62a through which the heat exchange medium HE2 flows. A compressor C2 is positioned between the cooling section side flow path 52a and the heating section side flow path 62a. A heat sink 90 and an expansion valve E2 are positioned between the heating section side flow path 62a and the cooling section side flow path 52a.

[0055] In the second embodiment, the compressor C2 compresses the heat exchange medium HE2 discharged from the cooling section side passage 52a of the cooling section 50a to a high temperature and high pressure and supplies it to the heating section side passage 62a. The heat sink 90 dissipates the heat from the heat exchange medium HE2 discharged from the heating section side passage 62a to the outside. A radiator or the like can be used as the heat sink 90. ​​The expansion valve E2 expands the heat exchange medium HE2, whose temperature has dropped due to heat dissipation by the heat sink 90, to a low temperature and low pressure and supplies it to the cooling section side passage 52a. As a result, the secondary battery BT is cooled by the cooling section 50a and heated by the heating section 60a.

[0056] In the control device 30a of the second embodiment, the control content performed by the output control unit 15a differs from the control content of the first embodiment. The output control unit 15a of the second embodiment controls the corrected heat generation amount Q calculated by the output calculation unit 14. b To output the same cooling and heating output, the compression ratio of compressor C2 is controlled. By controlling compressor C2, the corrected heat output Q b The same cooling and heating output is supplied to the case 40.

[0057] As described above, the cooling section 50a of the second embodiment includes a cooling section side flow path forming section 51a that forms a cooling section side flow path (second refrigerant flow path) 52a through which the heat exchange medium HE2 flows. The heating section 60a includes a heating section side flow path forming section 61a that forms a heating section side flow path (second heat medium flow path) 62a through which the heat exchange medium HE2 flows. In the second embodiment, since one type of heat exchange medium HE2 performs both cooling and heating within the case 40, the configuration of the temperature control system 100a is simplified.

[0058] <Third Embodiment> In the first embodiment described above, the minimum temperature T that the cooling unit 50 can set is as shown in formula (17). c The target battery temperature T is controlled by this method. b The lower limit temperature is determined, and the maximum temperature T that can be set for the heating unit 60 is determined. h Battery temperature T b An upper limit temperature was set. In contrast, in the third embodiment, from the viewpoint of suppressing the capacity degradation amount dCap of the secondary battery BT, the battery temperature T, which is the control target of the secondary battery BT, was set. b The temperature range is determined.

[0059] The capacity degradation amount dCap(Ah) of a secondary battery BT is calculated by the product of the degradation rate coefficient k, which is an intrinsic value for the battery material, and the square root of k, which is the total time during charging and discharging. The degradation rate coefficient k consists of the storage degradation rate coefficient, which is the degradation component during the time when no charging or discharging is occurring, and the high-temperature degradation rate coefficient k, which increases as the temperature rises during charging and discharging. HT The low-temperature degradation rate coefficient k increases as the temperature decreases during charging and discharging. LT It is expressed as the sum of these three components (formula (20) below).

number

[0060] The high-temperature degradation rate coefficient k in equation (11) HT And, the low-temperature degradation rate coefficient k LT These can be expressed as shown in equations (21) and (22) below. And the high-temperature degradation rate coefficient k HT And, the low-temperature degradation rate coefficient k LT The current-induced degradation rate coefficient (sum of degradation components) k is the sum of the two. HT+LT This can be expressed by the following equation (23), and there exists a battery temperature at which the minimum value is obtained.

number

[0061] Figure 9 shows the current-induced degradation rate coefficient k HT+LT This is an explanatory diagram. Figure 9 shows the high-temperature degradation rate coefficient k, which changes with the temperature of the secondary battery BT. HT Curve Ck representing HT (Dashed line) and the low-temperature degradation rate coefficient k LT Curve Ck representing LT (Dotted line) and the high-temperature degradation rate coefficient k HT and the low-temperature degradation rate coefficient k LT The current degradation rate coefficient k is the sum of the two. HT+LT The solid line represents Ck, which is the current degradation rate coefficient k. Figure 9 shows the current degradation rate coefficient k. HT+LT The curve Ck, which represents this, has a minimum value of 2.5 × 10 at approximately 25°C. -4 The minimum value is obtained by multiplying this minimum value by a predetermined coefficient m (for example, 1.1) of 1 or more, and determining two temperatures T1 and T2 (Figure 9) on the curve Ck. The output control unit 15 controls the temperature of the secondary battery BT during charging and discharging so that it is between T1 and T2. In the example shown in Figure 9, temperature T1 is approximately 20°C and temperature T2 is approximately 35°C.

[0062] In the third embodiment, the current degradation rate coefficient k shown in Figure 9 is further... HT+LTThe value of a predetermined coefficient m multiplied by the minimum value of changes before and after the switching time, which is described later, during the total charging and discharging time of the secondary battery BT. The predetermined coefficient ma after the switching time is a larger value than the predetermined coefficient m before the switching time. In other words, the temperature range of the secondary battery BT during charging and discharging after the switching time becomes wider and more relaxed.

[0063] Figure 10 is an explanatory diagram illustrating the relationship between the capacity degradation amount dCap, the degradation rate coefficient Σk, and time t of a secondary battery BT. As shown in Figure 10, the value obtained by dividing the capacity degradation amount dCap by the degradation rate coefficient Σk is expressed as the square root of time t, and therefore shows a nonlinearity in that it increases significantly in the initial stages of use of the secondary battery BT, and then increases more gradually thereafter. In other words, even with the same degradation rate coefficient and the same usage method, the degradation of the secondary battery BT progresses more rapidly in the initial stages of use.

[0064] In the third embodiment, the output control unit 15 calculates the slope of the capacity degradation amount dCap to the charge-discharge time, which is calculated from the charge-discharge time of the secondary battery BT and the capacity degradation amount dCap after charge-discharge. The output control unit 15 calculates the switching time, which is the charge-discharge time of the secondary battery BT at which the calculated slope is the same as the slope of the tangent to the square root of the charge-discharge time of the secondary battery BT. Specifically, the output control unit 15 calculates the standard judgment time t for capacity degradation. -0.5 (t=50000hr) is set, and the usage time of the secondary battery BT is set to zero and the reference judgment time t -0.5 The output control unit 15 calculates the straight line LN1 (dashed line) connecting the two points. The output control unit 15 calculates the point of contact Pc where the straight line LN2 (dotted line), which has the same slope as the straight line LN1, is tangent to the square root of time. The output control unit 15 calculates the time of the point of contact Pc as the switching time T_ SW This is set as the standard judgment time t for capacity degradation. -0.5 The specific numerical values ​​can be freely set by the user.

[0065] Figure 11 shows the switching time T_ SWThis is an explanatory diagram of the control temperature range of the secondary battery BT before and after. Figure 11 shows the temperatures T11 and T21, which are the control temperatures of the secondary battery BT, when a predetermined coefficient ma (=1.2), which is larger than the predetermined coefficient m (=1.1), is used, compared to Figure 9. In the third embodiment, the output control unit 15 has a switching time T_ SW Prior to the usage time, the temperature of the secondary battery BT is controlled within a range of T1 (20°C) to T2 (35°C) determined by a predetermined coefficient m. On the other hand, during the switching time T_ SW Subsequently, the output control unit 15 controls the cooling output within a range of T11 (17°C) to T21 (39°C) of the secondary battery BT, which is determined by a predetermined coefficient ma that is greater than a predetermined coefficient m.

[0066] Figure 12 is an explanatory diagram illustrating the changes in the upper and lower limits of the control temperature of the secondary battery BT before and after the switching time. Figure 12 shows that when the secondary battery BT is heated by the heating unit 60 from a cold environment, the usage time changes during the switching time T_ SW If the usage time is earlier than the switching time T_ SW In subsequent cases, the heating temperature of the secondary battery BT can be lower than temperature T1, at temperature T11. Also, when cooling the high-temperature secondary battery BT, the usage time is the switching time T_ SW If it is before this time, the secondary battery BT will be cooled to temperature T2. On the other hand, the usage time will be the switching time T_ SW In subsequent cases, the cooling temperature of the secondary battery BT can be a temperature T21, which is higher than temperature T2. That is, the switching time T_ SW Subsequently, by widening the temperature control range, the energy required for heating or cooling is suppressed, and the progression of the secondary battery BT's capacity degradation dCap is controlled over the switching time T_ SW It is suppressed to the same extent as before.

[0067] As described above, in the third embodiment, the output control unit 15 controls the current degradation rate coefficient k shown in Figure 9. HT+LT The minimum value of the curve Ck representing this is 2.5 × 10 -4The output control unit 15 determines two temperatures T1 and T2 on the curve Ck, which are obtained by multiplying this minimum value by a predetermined coefficient m (for example, 1.1) of 1 or more. The output control unit 15 controls the cooling output so that the temperature of the secondary battery BT during charging and discharging is between T1 and T2. In other words, in the third embodiment, the current degradation rate coefficient k HT+LT Based on the battery temperature during charging and discharging that minimizes the degradation of a certain factor, the control temperature range of the secondary battery BT is calculated using a predetermined coefficient m. This means that the temperature range is determined by setting the predetermined coefficient m, using the battery temperature at which capacity degradation is most suppressed as the reference. In other words, by setting a desired predetermined coefficient m, it becomes possible to set a temperature control range that suppresses capacity degradation of the secondary battery BT.

[0068] Furthermore, the output control unit 15 of the third embodiment calculates the slope of the capacity degradation amount dCap to the charge-discharge time, which is calculated from the charge-discharge time of the secondary battery BT and the capacity degradation amount dCap after charge-discharge. The output control unit 15 calculates the switching time, which is the charge-discharge time of the secondary battery BT at which the calculated slope and the slope of the tangent to the square root of the charge-discharge time of the secondary battery BT are the same. The output control unit 15 calculates the current degradation rate coefficient k shown in Figure 9. HT+LT The minimum value of the curve Ck representing this is 2.5 × 10 -4 The output control unit 15 determines two temperatures T1 and T2 on the curve Ck, which are obtained by multiplying this minimum value by a predetermined coefficient m (e.g., 1.1) of 1 or more. The output control unit 15 controls the cooling output so that the temperature of the secondary battery BT during charging and discharging is between T1 and T2. In the third embodiment, the calculated switching time T_ SW Based on this, the switching time T_ SW From this point onward, the temperature of the secondary battery BT during charging and discharging is controlled within a wide temperature control range calculated by a predetermined coefficient ma that is larger than a predetermined coefficient m. The capacity degradation of the secondary battery BT increases significantly in the initial stages of use and then slows down. In this regard, in the third embodiment, the switching time T_ at which the capacity degradation slows down is SW Calculate the switching time T_ SW From this point onward, the temperature of the secondary battery BT is controlled over a wider temperature range than during initial use. This allows for a switching time T_ SWIn the following steps, as shown in Figure 12, the target temperature for cooling a high-temperature secondary battery BT and the target temperature for heating a low-temperature secondary battery BT are relaxed. As a result, the energy required to reach the target temperature is reduced, and the capacity degradation of the secondary battery BT is suppressed.

[0069] <Fourth Embodiment> Figure 13 is a schematic block diagram of the temperature control system 100b of the fourth embodiment of the secondary battery BT. The temperature control system 100b of the fourth embodiment differs from the temperature control system 100 of the first embodiment in that it updates the map data stored in the map DB 20b. The electrical resistance of the secondary battery BT increases over time relative to the initial resistance R0, regardless of whether the secondary battery BT is used or not. The temperature control system 100b suppresses prediction errors based on the electrical resistance that increases over time. In the fourth embodiment, configurations that differ from the first embodiment will be described, and descriptions of configurations that are the same as in the first embodiment will be omitted.

[0070] As shown in Figure 13, the control device 30b of the temperature control system 100b of the fourth embodiment includes a CPU 10b, a map DB 20b, a power counter 25, and a storage counter 26. The power counter 25 measures the time from when charging or discharging of the secondary battery BT starts from a stopped state until the start of charging or discharging is completed. The storage counter 26 measures the time from when charging or discharging of the secondary battery BT is completed until charging or discharging of the secondary battery BT starts again. In other words, the power counter 25 measures the charge / discharge time, and the storage counter 26 measures the time when the secondary battery BT is in a non-use state. The values ​​of the power counter 25 and the storage counter 26 are reset each time the secondary battery BT switches between a charge / discharge state and a non-use state.

[0071] As shown in Figure 13, the CPU 10b functions as an acquisition unit 11, a correction unit 12, a resistance determination unit 13, an output calculation unit 14, an output control unit 15, an average calculation unit 16, and an update unit 17. The average calculation unit 16 calculates the average value of the state variables for both charging / discharging and non-use of the secondary battery BT. The temperature of the secondary battery BT, the state of charge (SOC) of the secondary battery BT, and the current flowing through the secondary battery BT change over time during charging / discharging and non-use. The average calculation unit 16 calculates the average value of the state variables that change over time.

[0072] The update unit 17 calculates the resistance increase ratio of the secondary battery BT's electrical resistance using the measurement time of the energization counter 25 or the storage counter 26 and the average value of the state quantities of the secondary battery BT during charging / discharging or when not in use, as calculated by the average calculation unit 16. The update unit 17 further updates the map data stored in the map DB 20b using the calculated electrical resistance increase ratio.

[0073] Figure 14 is an explanatory diagram illustrating the relationship between the state variables of a secondary battery BT and the resistance increase ratio of its electrical resistance. Figure 14 shows the change in the resistance increase ratio with respect to the number of cycles when the secondary battery BT is charged and discharged within different ranges of State of Charge (SOC). Figure 14 shows the line graphs LN60a (solid line) and LN60b (dashed line) representing the change when the secondary battery BT is charged and discharged within the SOC range of 0% to 60%, and the line graphs LN80a (thin solid line) and LN80b (dotted line) representing the change when the secondary battery BT is charged and discharged within the SOC range of 0% to 80%. Line graphs LN60a and LN80a represent the resistance increase ratio when the average temperature of the secondary battery BT during charging and discharging is room temperature (25°C). Line graphs LN60b and LN80b represent the resistance increase ratio when the average temperature of the secondary battery BT during charging and discharging is 40°C higher than room temperature (65°C). The resistance increase ratio is calculated by dividing the current resistance increase dR_bat by the initial resistance R0.

[0074] The resistance increase ratio dR_bat / R0 can be expressed using the square root of time t, as shown in equation (24) below. The degradation rate coefficient in equation (24) is expressed as shown in equation (25) below.

number

[0075] During storage, i.e., when the secondary battery BT is not in use, the resistance increase rate coefficient k_cal is determined by the average temperature T of the secondary battery BT and the state of charge (SOC). The resistance increase rate coefficient k_HT during energization and high temperature is determined by the average temperature T of the secondary battery BT. Note that lithium ejection in secondary batteries such as lithium-ion batteries contributes to capacity degradation, but ejected lithium is conductive and therefore does not contribute to resistance increase.

[0076] As shown in Figure 14, even with a charge / discharge state of charge (SOC) of 60%, the resistance increase ratio differs depending on the average temperature T of the secondary battery BT. Furthermore, even if the average temperature T of the secondary battery BT is the same, the resistance increase ratio will differ if the upper limit of the charge / discharge cycle SOC is different. Therefore, by updating the electrical resistance of the secondary battery BT in the map data using the resistance increase ratio calculated from the state variables of the secondary battery BT during charge / discharge and when not in use, the accuracy of the estimated electrical resistance and the estimated heat generation of the secondary battery BT is improved.

[0077] Figures 15 and 16 are flowcharts of the temperature control method for the secondary battery BT in the fourth embodiment. As shown in Figure 15, in the temperature control flow of the fourth embodiment, charging and discharging of the secondary battery BT is started first (step S21). The energization counter 25 starts measuring the time of the started charging and discharging (step S22). Subsequently, the processes from steps S23 to S31 are executed. Note that the processes from steps S23 to S31 are the same as the processes from steps S2 to S10 in the temperature control flow of the first embodiment shown in Figure 5, so the explanation is omitted.

[0078] Once step S31 is completed, it is determined whether or not to complete the charging and discharging of the secondary battery BT (step S32). The completion of charging and discharging is determined when an input unit (not shown in Figure 13) receives user input, or when either charging or discharging is completed to the target SOC. If it is determined that charging and discharging is not complete (step S32: NO), the processes from step S23 onwards are repeated.

[0079] In step S32, if it is determined that charging and discharging is complete (step S32: YES), the average calculation unit 16 calculates the average value of the state values ​​of the secondary battery BT during the time that charging and discharging was performed (step S33 in Figure 16). The average calculation unit 16 uses the acquired changes in the state values ​​during charging and discharging and the energizing time measured by the energizing counter 25 to calculate the average value of the state values ​​during charging and discharging.

[0080] The update unit 17 updates the map data stored in the map DB 20b (step S34). The update unit 17 calculates the resistance increase ratio of the secondary battery BT using the average value of the state quantities during charging and discharging and the charging and discharging time measured by the energization counter 25. The update unit 17 updates the map data using the calculated resistance increase ratio and the map data stored in the map DB 20b. The measurement time of the energization counter 25 is reset.

[0081] After the map data is updated, the storage counter 26 begins measuring the time the secondary battery BT is in a storage state when it is not being used (step S35). Three sensors SS1 to SS3 detect the state of the secondary battery BT in the storage state (step S36). Then, it is determined whether or not to complete the storage of the secondary battery BT (step S37). The determination of completion of the storage state is made by the start of charging or discharging of the secondary battery BT or the cessation of use of the secondary battery BT. If it is determined that the storage state should not be completed (step S37: NO), the process in step S36 is repeated.

[0082] In step S37, if it is determined that the storage state is complete (step S37: YES), the average calculation unit 16 calculates the average value of the state quantities of the secondary battery BT during the storage state (step S38). The average calculation unit 16 uses the acquired changes in the state quantities during the storage state and the storage time measured by the storage counter 26 to calculate the average value of the state quantities during the storage state. The measurement time of the storage counter 26 is reset.

[0083] The update unit 17 updates the map data stored in the map DB 20b (step S39). The update unit 17 calculates the resistance increase ratio of the secondary battery BT using the average value of the state quantities during the calculated storage state and the storage time measured by the storage counter 26. The update unit 17 updates the map data using the calculated resistance increase ratio and the map data stored in the map DB 20b.

[0084] After the map data is updated, it is determined whether or not to terminate the temperature control flow of the fourth embodiment (step S40). The termination determination in step S40 is made by stopping the use of the secondary battery BT being used and replacing it with another secondary battery BT, etc. If it is determined that the temperature control flow will not be terminated (step S40: NO), the processing from step S1 onwards in Figure 15 is repeated. If it is determined that the temperature control flow will be terminated (step S40: YES), the temperature control flow is terminated.

[0085] As described above, the average calculation unit 16 of the fourth embodiment calculates the average value of the state variables for both the charging / discharging and non-use periods of the secondary battery BT. The update unit 17 uses the measurement time of the energization counter 25 or storage counter 26 and the average value of the state variables of the secondary battery BT during charging / discharging or non-use calculated by the average calculation unit 16 to calculate the resistance increase ratio of the electrical resistance of the secondary battery BT. The update unit 17 further updates the map data stored in the map DB 20b using the calculated electrical resistance increase ratio. In the fourth embodiment, the pre-created map data is updated using the state variables and charging / discharging time of the secondary battery BT during charging / discharging and the state variables and charging / discharging time of the secondary battery BD when it is not in use. In the fourth embodiment, since the map data is updated according to the charging / discharging time and the non-use time of the secondary battery BT, the estimation accuracy of the electrical resistance of the secondary battery BT is improved. As a result, the heat generation amount Q of the corrected secondary battery BT is improved. b As the estimation accuracy improves, the progression of capacity degradation in the secondary battery BT is further suppressed.

[0086] <Modified examples of embodiments> The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit. For example, the following modifications are possible. Furthermore, in the above embodiments, some of the configurations implemented by hardware may be replaced with software, and conversely, some of the configurations implemented by software may be replaced with hardware.

[0087] The temperature control systems 100, 100a, and 100b described in the first to fourth embodiments above are examples. The temperature control system acquires state variables and vapor pressure inside the case 40, determines the electrical resistance of the secondary battery BT from the acquired state variables and pre-created map data, and calculates the corrected heat generation amount Q of the secondary battery using the determined electrical resistance and the acquired vapor pressure. b It can be deformed within the range that controls the same cooling output as the (heating output).

[0088] The heat transfer medium filled in case 40 and used to cool the secondary battery BT does not have to be a fluorocarbon-based medium 45, and is deformable within a range that allows it to change between liquid and gas and perform vapor heat transport. The cooling output of the cooling units 50, 50a may be controlled in ways other than the control of the evaporator 70 and the refrigerant pump P1 in the first embodiment, or the control of the compressor C2 in the second embodiment.

[0089] The temperature control systems 100, 100a, and 100b of the first, second, and fourth embodiments included heating units 60 and 60a, but the temperature control system does not need to be heated, and does not need to have heating units. In the first embodiment, a preferred temperature control range was defined from the settable temperatures of the cooling unit 50 and the heating unit 60. On the other hand, in the third embodiment, the temperature control range was defined from the viewpoint of suppressing the progression of capacity degradation dCap. However, in the modified temperature control system 100, it is not necessary to satisfy either the temperature control range defined in the first embodiment or the temperature control range defined in the third embodiment, or it may satisfy either one or both.

[0090] The embodiments of this specification have been described above based on the embodiments and modifications described above. The embodiments described above are for the purpose of facilitating understanding of this specification and do not limit it. This specification may be modified and improved without departing from its spirit and the scope of the claims, and equivalents thereof are included in this specification. Furthermore, any technical features that are not described as essential in this specification may be deleted as appropriate.

[0091] The present invention can also be realized in the following forms. [Application Example 1] A temperature control device for a secondary battery, A housing section for housing the aforementioned secondary battery, A heat transfer medium is filled into the aforementioned containment section and changes between the liquid and the substrate depending on the temperature, A cooling unit is positioned vertically above the aforementioned housing and cools the inside of the housing, A state quantity acquisition unit acquires state quantities including the temperature of the secondary battery, the charge level of the secondary battery, and the current flowing through the secondary battery. A vapor pressure acquisition unit that acquires the vapor pressure of the heat transfer medium, A resistance determination unit determines the electrical resistance of the secondary battery using map data that associates the electrical resistance of the secondary battery with the state quantity, which was created in advance, and the state quantity acquired by the state quantity acquisition unit. An output calculation unit calculates the heat output of the secondary battery by using the electrical resistance of the secondary battery determined by the resistance determination unit, and correcting the calculated heat output using the vapor pressure of the heat transfer medium obtained by the vapor pressure acquisition unit. An output control unit controls the cooling unit so that the calculated corrected heat output of the secondary battery and the cooling output of the cooling unit that cools the inside of the housing are the same, A temperature control device equipped with the following features. [Application Example 2] The temperature control device described in Application Example 1, further, A heating element is provided, which is positioned vertically below the aforementioned housing and heats the inside of the housing. The output control unit controls the cooling unit so that the cooling output of the cooling unit is equal to the sum of the heat output of the heating unit, which is determined by the temperature difference between the set temperature of the heating unit and the temperature inside the housing unit, and the heat output of the secondary battery after correction. [Application Example 3] A temperature control device as described in Application Example 1 or Application Example 2, The cooling unit is A refrigerant flow path forming section is positioned vertically above the aforementioned housing section and forms a first refrigerant flow path through which the refrigerant flows, A refrigerant pump that controls the flow rate of the refrigerant flowing through the first refrigerant passage, It has, The heating section is A heat medium channel forming section is located vertically below the aforementioned housing section and forms a first heat medium channel through which the heat medium flows, A heat medium pump that controls the flow rate of the heat medium flowing through the first heat medium channel, It has, The temperature control device further, An evaporator through which a first heat exchange medium flows, which cools the refrigerant by performing heat exchange with the refrigerant; A first compression unit for compressing the first heat exchange medium discharged from the evaporator, A condenser is supplied with the first heat exchange medium discharged from the first compression section, and heats the heat medium by performing heat exchange between the first heat exchange medium and the heat transfer medium. A first expansion unit expands the first heat exchange medium discharged from the condenser and supplies it to the evaporator, Equipped with, The output control unit is a temperature control device that controls the cooling output of the cooling unit by controlling the evaporator and the refrigerant pump. [Application Example 4] A temperature control device according to any one of Application Examples 1 to 3, The cooling section is positioned vertically above the housing section and has a cooling section side flow path forming section that forms a second refrigerant flow path through which the second heat exchange medium flows. The heating section is positioned vertically below the housing section and has a heating section side flow path forming section that forms a second heat medium flow path through which the second heat exchange medium flows. The temperature control device further, A second compression unit that compresses the second heat exchange medium discharged from the second refrigerant flow path and supplies it to the second heat medium flow path, A heat dissipation section for dissipating the second heat exchange medium discharged from the second heat medium flow path, A second expansion unit expands the second heat exchange medium discharged from the heat dissipation unit and supplies it to the second refrigerant flow path, Equipped with, The output control unit is a temperature control device that controls the cooling output of the cooling unit by controlling the second compression unit. [Application Example 5] A temperature control device according to any one of Application Examples 1 to 4, The output control unit, The lower limit temperature of the secondary battery is set using the ratio of the heat generated by the secondary battery before correction to the heat generated by the heating unit, the upper limit of the cooling output of the cooling unit, and the minimum settable temperature of the cooling unit. The upper limit temperature of the secondary battery is set using the heat generation ratio, the upper limit of the cooling output of the cooling unit, and the settable maximum temperature of the heating unit. A temperature control device that controls the cooling output of the cooling unit so that the temperature of the secondary battery during charging and discharging is above the lower limit temperature and below the upper limit temperature. [Application Example 6] A temperature control device according to any one of Application Examples 1 to 5, The output control unit, Of the degradation rate coefficients that determine the amount of capacity degradation of the secondary battery, the temperature at which the sum of degradation components is minimized is calculated, which is the sum of a high-temperature degradation component whose degradation rate coefficient increases as the temperature of the secondary battery increases during charging and discharging, and a low-temperature degradation component whose degradation rate coefficient increases as the temperature of the secondary battery decreases. The lower and higher temperatures of the sum of degradation components corresponding to the charging and discharging temperatures of the secondary battery are calculated by multiplying the calculated charging and discharging temperatures of the secondary battery by a predetermined coefficient of 1 or more. A temperature control device that controls the cooling output of the cooling unit so that the temperature of the secondary battery during charging and discharging is above the lower of two calculated temperatures and below the higher of two calculated temperatures. [Application Example 7] A temperature control device according to any one of Application Examples 1 to 6, The output control unit, The switching time is calculated, which is the charge-discharge time of the secondary battery at which the slope of the capacity degradation amount with respect to the charge-discharge time, calculated from the charge-discharge time of the secondary battery and the capacity degradation amount after charge-discharge, is the same as the slope of the tangent to the square root of the charge-discharge time of the secondary battery. A temperature control device that controls the cooling output of the cooling unit using the predetermined coefficient until the charge / discharge time of the secondary battery reaches the switching time, and controls the cooling output of the cooling unit so that the temperature of the secondary battery is above the lower of the two temperatures calculated using a coefficient larger than the predetermined coefficient and below the higher of the two temperatures. [Application Example 8] A temperature control device according to any one of Application Examples 1 to 7, further, A temperature control device comprising an update unit that updates the map data using the amount of change in the electrical resistance of the secondary battery calculated using the charge-discharge time of the secondary battery and the average value of the state variables, and the amount of change in electrical resistance calculated using the time of the secondary battery when it is not being charged or discharged and the average value of the state variables. [Application Example 9] A method for controlling the temperature of a secondary battery, wherein a computer... A state quantity acquisition step that acquires state quantities including the temperature of the secondary battery housed in the housing, the charge level of the secondary battery, and the current flowing through the secondary battery, A vapor pressure acquisition step is performed to acquire the vapor pressure of a heat transfer medium that is filled in the aforementioned containment section and changes between liquid and gas depending on the temperature, A resistance determination step in which the electrical resistance of the secondary battery is determined using map data that associates the electrical resistance of the secondary battery with the state variables, which was prepared in advance, and the acquired state variables, An output calculation step which involves calculating the amount of heat generated by the secondary battery using the determined electrical resistance of the secondary battery, and then calculating the heat output of the secondary battery by correcting the calculated amount of heat generated using the vapor pressure of the acquired heat transfer medium, An output control step that controls the cooling unit so that the calculated corrected heat output of the secondary battery and the cooling output of the cooling unit, which is positioned vertically above the housing and cools the inside of the housing, are the same; A temperature control method that performs this action. [Application Example 10] It is a computer program, A state quantity acquisition function that acquires state quantities including the temperature of the secondary battery housed in the housing, the charge level of the secondary battery, and the current flowing through the secondary battery, A vapor pressure acquisition function is provided to acquire the vapor pressure of a heat transfer medium that is filled in the aforementioned storage section and changes between liquid and gas depending on the temperature, A resistance determination function that determines the electrical resistance of the secondary battery using map data that associates the electrical resistance of the secondary battery with the state variables, which was created in advance, and the acquired state variables, An output calculation function that calculates the heat generation amount of the secondary battery using the determined electrical resistance of the secondary battery, and corrects the calculated heat generation amount using the acquired vapor pressure of the heat transfer medium to calculate the heat output of the secondary battery, An output control function that controls the cooling unit so that the calculated corrected heat output of the secondary battery and the cooling output of the cooling unit, which is positioned vertically above the housing and cools the inside of the housing, are the same; A computer program that causes a computer to execute something. [Explanation of Symbols]

[0092] 10,10b…CPU 11…Acquisition part 12...Correction section 13…Resistance determination section 14…Output calculation unit 15, 15a... Output control section 16...Average calculation section 17…Update section 25... Power-on counter 26... Save Counter 30, 30a, 30b... Control devices 40… Case (storage compartment) 45...Fluorocarbon-based fluids (thermal fluids) 50,50a...Cooling section 51...Refrigerant flow path forming section 51a…Cooling part side flow path forming part 52…Refrigerant flow path (First refrigerant flow path) 52a... Cooling section side flow path (second refrigerant flow path) 53… Refrigerant 60,60a...Heating section 61... Heat fluid channel forming section 61a...Heating part side flow path forming part 62…Heat transfer fluid channel (first heat transfer fluid channel) 62a... Heating section side flow path (second heat transfer fluid flow path) 63… Heat transfer fluid 70... Evaporator 80... Condenser 90…Radiator (heat radiation part) 100, 100a, 100b… Temperature control system BT…Secondary battery C1…Compressor (First Compression Section) C2…Compressor (Second Compression Section) 20, 20a, 20b… Map Database E1…Expansion valve (first expansion section) E2...Expansion valve (second expansion section) FP1…First channel HE1…Heat exchange medium (first heat exchange medium) HE2…Heat exchange medium (second heat exchange medium) P1... Refrigerant pump P2... Heat transfer pump ΔQ batt ...heat generation due to external disturbances Q b ...Heat generation of the secondary battery after correction Q batt ...heat generation from secondary batteries R0...Initial resistance R batt ...electric resistance SS1…Temperature sensor (state quantity acquisition unit) SS2…Charge level sensor (status value acquisition unit) SS3…Current sensor (state quantity acquisition unit) SS4…Pressure sensor (vapor pressure acquisition unit) T_ SW ...switching time dCap… Amount of capacity degradation in a secondary battery m, ma… predetermined coefficient x…bottom heating ratio

Claims

1. A temperature control device for a secondary battery, A housing section for housing the aforementioned secondary battery, A heat transfer medium is filled into the aforementioned containment section and changes between the liquid and the substrate depending on the temperature, A cooling unit is positioned vertically above the aforementioned housing and cools the inside of the housing, A state quantity acquisition unit acquires state quantities including the temperature of the secondary battery, the charge level of the secondary battery, and the current flowing through the secondary battery. A vapor pressure acquisition unit that acquires the vapor pressure of the heat transfer medium, A resistance determination unit determines the electrical resistance of the secondary battery using map data that associates the electrical resistance of the secondary battery with the state quantities, which was created in advance, and the state quantities acquired by the state quantity acquisition unit. An output calculation unit calculates the heat output of the secondary battery by using the electrical resistance of the secondary battery determined by the resistance determination unit, and correcting the calculated heat output using the vapor pressure of the heat transfer medium obtained by the vapor pressure acquisition unit. An output control unit controls the cooling unit so that the calculated corrected heat output of the secondary battery and the cooling output of the cooling unit that cools the inside of the housing are the same. A temperature control device equipped with the following features.

2. A temperature control device according to claim 1, further, A heating element is provided, which is positioned vertically below the aforementioned housing and heats the inside of the housing. The output control unit controls the cooling unit so that the cooling output of the cooling unit is equal to the sum of the heat output of the heating unit, which is determined by the temperature difference between the set temperature of the heating unit and the temperature inside the housing unit, and the heat output of the secondary battery after correction.

3. A temperature control device according to claim 2, The cooling unit is A refrigerant flow path forming section is positioned vertically above the aforementioned housing section and forms a first refrigerant flow path through which the refrigerant flows, A refrigerant pump that controls the flow rate of the refrigerant flowing through the first refrigerant passage, It has, The aforementioned heating section is A heat medium channel forming section is positioned vertically below the aforementioned housing section and forms a first heat medium channel through which the heat medium flows, A heat medium pump that controls the flow rate of the heat medium flowing through the first heat medium channel, It has, The temperature control device further, An evaporator through which a first heat exchange medium flows, which cools the refrigerant by performing heat exchange with the refrigerant; A first compression unit for compressing the first heat exchange medium discharged from the evaporator, A condenser is supplied with the first heat exchange medium discharged from the first compression section, and heats the heat transfer medium by performing heat exchange between the first heat exchange medium and the heat transfer medium. A first expansion unit expands the first heat exchange medium discharged from the condenser and supplies it to the evaporator, Equipped with, The output control unit is a temperature control device that controls the cooling output of the cooling unit by controlling the evaporator and the refrigerant pump.

4. A temperature control device according to claim 2, The cooling section is positioned vertically above the housing section and has a cooling section side flow path forming section that forms a second refrigerant flow path through which the second heat exchange medium flows. The heating section is positioned vertically below the housing section and has a heating section side flow path forming section that forms a second heat medium flow path through which the second heat exchange medium flows. The temperature control device further, A second compression unit that compresses the second heat exchange medium discharged from the second refrigerant flow path and supplies it to the second heat medium flow path, A heat dissipation section for dissipating the second heat exchange medium discharged from the second heat medium flow path, A second expansion unit expands the second heat exchange medium discharged from the heat dissipation unit and supplies it to the second refrigerant flow path, Equipped with, The output control unit is a temperature control device that controls the cooling output of the cooling unit by controlling the second compression unit.

5. A temperature control device according to claim 2, The output control unit, The lower limit temperature of the secondary battery is set using the ratio of the heat generated by the secondary battery before correction to the heat generated by the heating unit, the upper limit of the cooling output of the cooling unit, and the minimum settable temperature of the cooling unit. The upper limit temperature of the secondary battery is set using the heat generation ratio, the upper limit of the cooling output of the cooling unit, and the settable maximum temperature of the heating unit. A temperature control device that controls the cooling output of the cooling unit so that the temperature of the secondary battery during charging and discharging is above the lower limit temperature and below the upper limit temperature.

6. A temperature control device according to claim 2, The output control unit, Of the degradation rate coefficients that determine the amount of capacity degradation of the secondary battery, the temperature at which the sum of degradation components is minimized is calculated, which is the sum of a high-temperature degradation component whose degradation rate coefficient increases as the temperature of the secondary battery increases during charging and discharging, and a low-temperature degradation component whose degradation rate coefficient increases as the temperature of the secondary battery decreases. The lower and higher temperatures of the sum of degradation components corresponding to the charging and discharging temperatures of the secondary battery are calculated by multiplying the calculated charging and discharging temperatures of the secondary battery by a predetermined coefficient of 1 or more. A temperature control device that controls the cooling output of the cooling unit so that the temperature of the secondary battery during charging and discharging is above the lower of two calculated temperatures and below the higher of two calculated temperatures.

7. A temperature control device according to claim 6, The output control unit, The switching time is calculated, which is the charge-discharge time of the secondary battery at which the slope of the capacity degradation amount with respect to the charge-discharge time, calculated from the charge-discharge time of the secondary battery and the capacity degradation amount after charge-discharge, is the same as the slope of the tangent to the square root of the charge-discharge time of the secondary battery. A temperature control device that controls the cooling output of the cooling unit using the predetermined coefficient until the charge / discharge time of the secondary battery reaches the switching time, and controls the cooling output of the cooling unit so that the temperature of the secondary battery is above the lower of the two temperatures calculated using a coefficient larger than the predetermined coefficient and below the higher of the two temperatures.

8. A temperature control device according to any one of claims 1 to 7, further, A temperature control device comprising an update unit that updates the map data using the amount of change in the electrical resistance of the secondary battery calculated using the charge-discharge time of the secondary battery and the average value of the state variables, and the amount of change in electrical resistance calculated using the time of the secondary battery when it is not being charged or discharged and the average value of the state variables.

9. A method for controlling the temperature of a secondary battery, wherein a computer... A state quantity acquisition step that acquires state quantities including the temperature of the secondary battery housed in the housing, the charge level of the secondary battery, and the current flowing through the secondary battery, A vapor pressure acquisition step is performed to acquire the vapor pressure of a heat transfer medium that is filled in the aforementioned containment section and changes between liquid and gas depending on the temperature, A resistance determination step in which the electrical resistance of the secondary battery is determined using map data that associates the electrical resistance of the secondary battery with the state variables, which was prepared in advance, and the acquired state variables, An output calculation step is to calculate the heat generation amount of the secondary battery using the determined electrical resistance of the secondary battery, and to calculate the heat output of the secondary battery by correcting the calculated heat generation amount using the vapor pressure of the acquired heat transfer medium, An output control step that controls the cooling unit so that the calculated corrected heat output of the secondary battery and the cooling output of the cooling unit, which is positioned vertically above the housing and cools the inside of the housing, are the same; A temperature control method that performs this action.

10. It is a computer program, A state quantity acquisition function that acquires state quantities including the temperature of the secondary battery housed in the housing, the charge level of the secondary battery, and the current flowing through the secondary battery, A vapor pressure acquisition function is provided to acquire the vapor pressure of a heat transfer medium that is filled in the aforementioned storage section and changes between liquid and gas depending on the temperature, A resistance determination function that determines the electrical resistance of the secondary battery using map data that associates the electrical resistance of the secondary battery with the state variables, which was created in advance, and the acquired state variables, An output calculation function that calculates the heat output of the secondary battery by using the determined electrical resistance of the secondary battery, and correcting the calculated heat output using the vapor pressure of the acquired heat transfer medium, An output control function that controls the cooling unit so that the calculated corrected heat output of the secondary battery and the cooling output of the cooling unit, which is positioned vertically above the housing and cools the inside of the housing, are the same; A computer program that causes a computer to execute something.

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