Control device, control method, and program

Abstract

To prevent deterioration of a lithium metal battery.SOLUTION: A determination device comprises: an acquisition unit that acquires the transition curve of the voltage of a lithium metal battery comprising a negative electrode including lithium; and a determination unit that determines recommendation suppression time for recommending suppression of charge and discharge of the lithium metal battery, on the basis of the rate of change in the voltage within a short time constant range corresponding to a range of a short time constant in the transition curve.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a control device, a control method, and a program.

Background Art

[0002] In recent years, in order to enable more people to access affordable, reliable, sustainable, and advanced energy, research and development have been conducted to contribute to energy efficiency. Regarding such technologies, as a secondary battery, a lithium metal battery that uses lithium metal as the negative electrode has attracted attention. A lithium metal battery includes a positive electrode, a negative electrode having a metal lithium layer, and an electrolyte provided between the positive electrode and the negative electrode.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] A lithium metal battery uses lithium in the negative electrode and has a mechanism for charging and discharging by deposition and dissolution of lithium. In a secondary battery, if the charge and discharge rate is not appropriately controlled, the durability may not be fully exhibited, and the same can be said for a secondary battery that is a lithium metal battery.

[0005] The present invention has been made in consideration of such circumstances, and one of its purposes is to suppress a decrease in the durability of a lithium metal battery. And by extension, it contributes to energy efficiency. [Means for solving the problem]

[0006] The control device, control method, and program according to this invention employ the following configuration. (1) A control device according to one aspect of the present invention is a control device comprising: an acquisition unit that acquires charge and discharge rate information relating to the charge and discharge rate during charging and discharging of a lithium metal battery having a lithium-containing negative electrode; and a determination unit that determines the charge and discharge content for the lithium metal battery based on the charge and discharge rate information.

[0007] (2) In the embodiment of (1) above, the charge-discharge rate information is discharge rate information relating to the discharge rate for the lithium metal battery, and the determination unit determines a small charge current as the charge-discharge content when the charge rate included in the charge-discharge rate information is less than or equal to a first specified value.

[0008] (3) In the embodiment of (1) above, the charge-discharge rate information is discharge rate information relating to the current discharged from the lithium metal battery, and the determination unit determines a large discharge current as the charge-discharge content when the discharge rate included in the charge-discharge rate information is less than or equal to a second specified value.

[0009] (4) In the embodiment of (1) above, the charge-discharge rate information is information relating to the average discharge rate or the average charge-discharge rate difference within a specified time.

[0010] (5) In the embodiment of (1) above, the acquisition unit acquires the charge-discharge rate based on information relating to the charge-discharge history of the lithium metal battery.

[0011] (6) In the embodiment of (5) above, the lithium metal battery is mounted on a vehicle, and the determination unit determines the charge and discharge contents when the vehicle is performing charge and discharge with an external device.

[0012] (7) A control method according to one aspect of the present invention is a control method in which a computer acquires charge and discharge rate information relating to the charge and discharge rate during charging and discharging of a lithium metal battery having a lithium-containing negative electrode, and determines the charge and discharge content for the lithium metal battery based on the charge and discharge rate information.

[0013] (8) A program according to one aspect of the present invention is a program that causes a computer to acquire charge-discharge rate information relating to the charge-discharge rate during charging and discharging of a lithium metal battery having a lithium-containing negative electrode, and to determine the charge-discharge content for the lithium metal battery based on the charge-discharge rate information. [Effects of the Invention]

[0014] According to embodiments (1) to (8), the deterioration of the durability of lithium metal batteries can be suppressed. [Brief explanation of the drawing]

[0015] [Figure 1] This figure shows an example of the configuration of a vehicle M equipped with the control device 100 of the embodiment. [Figure 2] This figure shows an example of the configuration of the control device 100. [Figure 3] This figure shows an example of the visualized first reference control map 121 and first control map 122. [Figure 4] This figure shows an example of the visualized second reference control map 123 and second control map 124. [Figure 5] A flowchart showing an example of the processing performed by the control device 100. [Modes for carrying out the invention]

[0016] Hereinafter, embodiments of the control device, control method, and program of the present invention will be described with reference to the drawings.

[0017] FIG. 1 is a diagram showing an example of the configuration of a vehicle M equipped with a control device 100 according to an embodiment. The control device 100 according to the embodiment controls the charge and discharge amount of current with respect to a lithium metal battery 10 mounted on the vehicle M. The lithium metal battery 10 includes a negative electrode containing lithium. The lithium metal battery 10 is a secondary battery that can be charged and discharged.

[0018] The vehicle M is included in so-called V2H (Vehicle to Home) and V2X (Vehicle to X). The vehicle M can, for example, charge and discharge with an external device such as a charging and discharging facility 80. When starting to charge and discharge with the vehicle M, the charging and discharging facility 80 transmits a V2H request to the vehicle M. The vehicle M starts charging and discharging with the charging and discharging facility 80 by acquiring the V2H request.

[0019] The charging and discharging facility 80 discharges current to the lithium metal battery 10 mounted on the vehicle M to charge the lithium metal battery 10. A current adjustment device 70 mounted on the vehicle M converts an alternating current into a direct current by the charging and discharging facility 80, steps down the current, and charges the lithium metal battery 10. The lithium metal battery 10 mounted on the vehicle M discharges current to charge the charging and discharging facility 80. The current adjustment device 70 mounted on the vehicle M converts the direct current discharged by the lithium metal battery 10 into an alternating current, steps up the current, and charges the charging and discharging facility 80.

[0020] In addition to the lithium metal battery 10, the vehicle M mounts an electric device 40, a measuring device 50, a control unit 60, and a current adjustment device 70. The measuring device 50 includes, for example, a voltage detector 51 and a current detector 52. The control unit 60 includes, for example, a control device 100 and an ECU (Electronic Control Unit) 200.

[0021] The lithium metal battery 10 is, for example, a semi-solid battery. The lithium metal battery 10 comprises, for example, a positive electrode 11, a negative electrode 12, and an electrolyte 13. The positive electrode 11 comprises, for example, a positive electrode current collector 11A and a positive electrode active material layer 11B. The positive electrode current collector 11A is made of, for example, a current collector foil such as aluminum. The positive electrode active material layer 11B is made of, for example, a layer such as lithium cobalt oxide.

[0022] The negative electrode 12 comprises, for example, a negative electrode current collector 12A and a negative electrode active material layer 12B. The negative electrode current collector 12A is made of, for example, a current collector foil made of copper. The negative electrode active material layer 12B is made of, for example, a metallic lithium layer. The electrolyte 13 is a semi-solid electrolyte containing lithium ions Li+. The electrolyte 13 is separated into a positive electrode 11 side and a negative electrode 12 side by a separator 13S.

[0023] During discharge, when the lithium metal battery 10 supplies power to the electrical equipment 40 mounted on the vehicle M, lithium ions (Li+) flow from the negative electrode active material layer 12B through the separator 13S to the positive electrode 11. Along with the flow of lithium ions (Li+), electrons (e) flow from the negative electrode 12 through the circuit of the electrical equipment 40 to the positive electrode 11. The flow of lithium ions (Li+) and electrons (e) causes a current to flow from the positive electrode 11 to the negative electrode 12, discharging the lithium metal battery 10. In the negative electrode active material layer 12B, metallic lithium dissolves as the lithium metal battery 10 discharges.

[0024] The lithium metal battery 10 is charged by a charge / discharge facility 70 located outside the vehicle M. The charge / discharge facility 70 is installed, for example, at the vehicle M owner's home or a charging station. During charging, lithium ions Li+ flow from the positive electrode active material layer 11B through the separator 13S to the negative electrode 12 side.

[0025] Along with the flow of lithium ions (Li+), electrons (e) flow from the positive electrode 11 through the charge / discharge equipment 80 to the 12 side. The flow of lithium ions (Li+) and electrons (e) causes an electric current to flow from the negative electrode 12 side to the positive electrode 11 side, charging the lithium metal battery 10. In the negative electrode active material layer 12B, metallic lithium is deposited as the lithium metal battery 10 is charged.

[0026] The electrical equipment 40 includes various devices mounted on the vehicle M and powered by the lithium metal battery 10. The electrical equipment 40 includes, for example, a drive motor for moving the vehicle M, an air conditioning control device for controlling the air conditioning inside the vehicle M, and a monitor for displaying images to provide various information to the occupants.

[0027] The voltage detector 51 in the measuring instrument 50 detects the voltage value of the terminal voltage of the lithium metal battery 10. The voltage detector 51 outputs the detected voltage value to the control device 100 of the control unit 60. The current detector 52 detects the current value of the current flowing from the positive electrode 11 to the negative electrode 12 of the lithium metal battery 10. The current detector 52 outputs the detected current value to the control device 100.

[0028] Figure 2 shows an example of the configuration of the control device 100. The control device 100 includes, for example, a communication unit 110, a storage unit 120, and a processing unit 130. The communication unit 110 transmits and receives signals between the control device 100 and an external device. For example, the communication unit 110 transmits a current supply signal generated by the processing unit 130 to the AC power supply 20. The communication unit 110 receives a current signal transmitted by the ammeter 30. The transmission and reception performed by the communication unit 110 may be wired communication via wiring or wireless communication via a network.

[0029] The storage unit 120 consists of, for example, an HDD (Hard Disk Drive) or flash memory. The storage unit 120 may also be an external drive device connected to the control device 100. The storage unit 120 includes, for example, a first reference control map 121, a first control map 122, a second reference control map 123, a fourth reference control map, and a V2H history 125.

[0030] Figure 3 shows an example of the visualized first reference control map 121 and first control map 122. Both the first reference control map 121 and the first control map 122 are maps that show the magnitude of the charging current according to the charge-discharge rate difference during charging of a lithium metal battery. The first control map 122 is a map that has been created so that the charging current is smaller than that of the first reference control map 121.

[0031] The V2H history 125 contains information about the charging and discharging history of the lithium metal battery 10 with external devices, such as the charging and discharging equipment 80 of the vehicle M, via V2H. In the vehicle M, the V2H history 125 is updated each time charging and discharging is performed via V2H. The V2H history 125 is an example of a charging and discharging history.

[0032] Figure 4 shows an example of the visualized second reference control map 123 and second control map 124. The second reference control map 123 and second control map 124 are maps that show the magnitude of the discharge current according to the discharge rate during the discharge of a lithium metal battery. The second control map 124 is a map that has been created so that the discharge current is larger than that of the second reference control map 123.

[0033] The processing unit 130 includes, for example, an acquisition unit 131, a determination unit 132, and a notification unit 133. These components are realized, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), or GPU (Graphics Processing Unit), or by the cooperation of software and hardware.

[0034] The program may be stored in advance in a storage unit 120 (a storage device equipped with a non-transient storage medium) such as an HDD or flash memory, or it may be stored in a removable storage medium (a non-transient storage medium) such as a DVD or CD-ROM, and installed when the storage medium is inserted into a drive device.

[0035] The acquisition unit 131 acquires the V2H request transmitted by the charging / discharging equipment 80. The acquisition unit 131 acquires the voltage value output by the voltage detector 51 and the current value output by the current detector 52. The acquisition unit 131 adds the acquired voltage and current values ​​to the V2H history 125 stored in the storage unit 120. The acquisition unit 131 updates the V2H history 125 by adding the voltage and current values.

[0036] The acquisition unit 131 calculates the magnitude (current value) of the charge-discharge current of the lithium metal battery 10 and the difference between the charge-discharge currents based on the detection results of the voltage detector 51 and the current detector 52, and acquires this information as charge-discharge rate information regarding the charge-discharge rate during the charging and discharging of the lithium metal battery 10. The charge-discharge rate includes the discharge rate and the charge-discharge rate difference, and the charge-discharge rate information includes the discharge rate information and the charge-discharge rate difference information. The charge rate may be used instead of the charge-discharge rate difference. The charge-discharge rate information is information regarding the average discharge rate or the average charge-discharge rate difference within a specified time. The specified time may be determined to be an appropriate time.

[0037] The determination unit 132 determines the charge and discharge content for the lithium metal battery 10 based on the charge and discharge rate information acquired by the acquisition unit 131. For example, when the charge and discharge rate difference included in the charge and discharge rate difference information is less than or equal to the first specified value R1, the determination unit 132 determines a small charge current as the charge content. For example, when the discharge rate included in the discharge rate information is less than or equal to the second specified value R2 exceed Sometimes, the discharge characteristics greatly determine the discharge current.

[0038] The determination unit 132 selects a control map to be referenced when determining the charging current, for example, based on the charge / discharge rate difference included in the charge / discharge rate difference information acquired by the acquisition unit 131, as a recommended charge / discharge control map. For example, when the charge / discharge rate difference is less than or equal to a first specified value R1, the determination unit 132 selects a first control map 122 and determines the charging current by referencing the charge / discharge rate difference to the first control map 122. For example, when the charge / discharge rate difference exceeds a first specified value R1, the determination unit 132 selects a first reference control map 121 and determines the charging current by referencing the charge / discharge rate difference to the first reference control map 121.

[0039] The determination unit 132 selects a control map to be referenced when determining the discharge current, for example, based on the discharge rate included in the discharge rate information acquired by the acquisition unit 131, as the recommended charge / discharge control map. For example, when the discharge rate exceeds the second specified value R2, the determination unit 132 selects the second control map 124 and determines the discharge current by referring the discharge rate to the second control map 124. For example, when the discharge rate is less than or equal to the second specified value R2, the determination unit 132 selects the second reference control map 123 and determines the charge current by referring the discharge rate to the second reference control map 123.

[0040] The determination unit 132 determines, for example, the charge and discharge details when the vehicle M is performing charge and discharge with an external device such as a charge and discharge equipment 80. The determination unit 132 determines the charge and discharge details when, for example, charge and discharge exceeding a specified current amount is repeated in V2H. The specified current amount and the frequency of charge and discharge repetitions may be determined as appropriate.

[0041] The determination unit 132 determines, for example, the discharge current when the lithium metal battery 10 of the vehicle M is discharging current to the charge / discharge equipment 80. The determination unit 132 also determines, for example, the charge current when the lithium metal battery 10 of the vehicle M is charging current supplied by the charge / discharge equipment 80. The discharge current and charge current are defined by current values, but may also be defined by current quantities.

[0042] The notification unit 133 notifies the ECU 200 of the charging current or discharging current determined by the determination unit 132. Based on the charging current and discharging current notified by the notification unit 133, the ECU 200 generates current value information regarding the charging and discharging current values ​​of the lithium metal battery 10. The ECU 200 transmits the generated current value information to the current adjustment device 70.

[0043] Next, the processing in the control device 100 of the embodiment will be described. Figure 5 is a flowchart showing an example of the processing of the control device 100. The processing shown in Figure 5 is executed, for example, after the vehicle M is connected to the charging and discharging equipment 80. First, the control device 100 determines whether the acquisition unit 131 has acquired a charging and discharging request (step S101).

[0044] If the acquisition unit 131 determines that a V2H request has not been acquired, it repeats the process in step S101. If the acquisition unit 131 determines that a V2H request has been acquired, it refers to the charge / discharge history stored in the storage unit 120 (step S103) and determines whether or not charge / discharge operations exceeding a specified current amount have been repeated (step S105).

[0045] If the acquisition unit 131 determines that charging and discharging exceeding a specified current amount has not been repeated, the control device 100 terminates the process shown in Figure 5. If it determines that charging and discharging exceeding a specified current amount has been repeated, the acquisition unit 131 determines whether the average discharge rate or the average charge-discharge rate difference is less than or equal to a specified value (step S107). Here, when the lithium metal battery 10 is discharging, it determines whether the average discharge rate is less than or equal to a first specified value R1, and when the lithium metal battery 10 is charging, it determines whether the average charge-discharge rate difference is less than or equal to a second specified value R2.

[0046] If the acquisition unit 131 determines that the average discharge rate or the average charge-discharge rate difference is below a specified value, the determination unit 132 selects a control map that results in a smaller charge-discharge current (first control map 122 or second reference control map 123) as the recommended charge-discharge control map (step S109). If the acquisition unit 131 determines that the average discharge rate or the average charge-discharge rate difference exceeds a specified value, the determination unit 132 selects a control map that results in a larger charge-discharge current (first reference control map 121 or second control map 124) as the recommended charge-discharge control map (step S111).

[0047] Next, the determination unit 132 defines the selected recommended charge / discharge control map (step S113), and calculates the charging current or discharging current by referring the discharge rate or charge / discharge rate difference to the recommended charge / discharge control map (step S113). The notification unit 133 generates current value information based on the charging current or discharging current determined by the determination unit 132 and transfers it to the ECU 200 (step S115). In this way, the control device 100 completes the process shown in Figure 5.

[0048] Based on the current value information transmitted by the notification unit 133 of the control device 100, the ECU 200 controls the current adjustment device 70 to adjust the current values ​​of the charging current and discharging current supplied to the lithium metal battery 10. Under the control of the ECU 200, the lithium metal battery 10 is charged and discharged with the charging current and discharging current values ​​adjusted by the current adjustment device 70.

[0049] The control device 100 of this embodiment determines the charge and discharge content for the lithium metal battery 10 based on the charge and discharge rate during charging and discharging of the lithium metal battery 10. For example, the control device 100 reduces the charging current when the charge rate is below a first specified value, and increases the discharge current when the charge and discharge rate exceeds a second specified value. Therefore, low-rate charging and high-rate discharging can be achieved, and degradation of the lithium metal battery 10 can be effectively suppressed.

[0050] The embodiments described above can be expressed as follows. A storage medium that stores computer-readable instructions, A processor connected to the storage medium, The processor executes the computer-readable instructions to: Computers We obtain charge / discharge rate information regarding the charge / discharge rate during charging and discharging of a lithium metal battery equipped with a lithium-containing negative electrode. Based on the charge / discharge rate information, the charge / discharge details for the lithium metal battery are determined. Control device.

[0051] Although embodiments for carrying out the present invention have been described above using examples, the present invention is not limited in any way to these embodiments, and various modifications and substitutions can be made without departing from the spirit of the present invention. [Explanation of symbols]

[0052] 10 Lithium metal batteries 11 Positive electrode 11A positive electrode current collector 11B Positive electrode active material layer 12 Negative electrode 12A negative electrode current collector 12B Negative active material layer 13 Electrolytes 13S Separator 20 AC power supply 30 ammeter 40 Electrical equipment 50 Measuring Instruments 51 Voltage detector 52 Current detector 60 control units 70 Current regulator 100 Control device 110 Communications Department 120 Storage section 121 First Reference Control Map 122 First Control Map 123 Second Reference Control Map 124 Second Control Map 125 V2H History 130 Processing Unit 131 Acquisition Department 132 Decision Section 133 Notification Department M Vehicle R1 First specified value R2 Second specified value

Claims

1. An acquisition unit that acquires charge / discharge rate information regarding the charge / discharge rate during charging and discharging of a lithium metal battery having a lithium-containing negative electrode, The system includes a determination unit that determines the charge and discharge content for the lithium metal battery based on the charge and discharge rate information, The charge / discharge rate information is discharge rate information relating to the discharge rate of the lithium metal battery, The determination unit determines a smaller charging current as the charge / discharge content when the charging rate included in the charge / discharge rate information is less than or equal to a first specified value. Control device.

2. An acquisition unit that acquires charge / discharge rate information relating to the charge / discharge rate during charging and discharging of a lithium metal battery having a lithium-containing negative electrode, The system includes a determination unit that determines the charge and discharge content for the lithium metal battery based on the charge and discharge rate information, The charge / discharge rate information is discharge rate information relating to the current discharged from the lithium metal battery, The determination unit determines a larger discharge current as the charge / discharge content when the discharge rate included in the charge / discharge rate information exceeds a second specified value. Control device.

3. The aforementioned charge / discharge rate information is information regarding the average discharge rate or the difference between the average charge and discharge rates within a specified time period. The control device according to claim 1.

4. The acquisition unit refers to the charge and discharge history of the lithium metal battery to determine whether charge and discharge operations exceeding a specified current amount have been repeated, and if charge and discharge operations exceeding a specified current amount have been repeated, it determines whether the charge rate included in the charge and discharge rate information is less than or equal to a first specified value. The control device according to claim 1.

5. The US lithium metal battery is installed in a vehicle. The determination unit determines the charge and discharge details when the vehicle is performing charge and discharge with an external device. The control device according to claim 1.

6. Computers We obtain charge / discharge rate information regarding the charge / discharge rate during charging and discharging of a lithium metal battery equipped with a lithium-containing negative electrode. Based on the charge / discharge rate information, the charge / discharge details for the lithium metal battery are determined. The charge / discharge rate information is discharge rate information relating to the discharge rate of the lithium metal battery, The computer determines a small charging current as the charge / discharge content when the charging rate included in the charge / discharge rate information is less than or equal to a first specified value. Control method.

7. On the computer, We obtain charge / discharge rate information regarding the charge / discharge rate during charging and discharging of a lithium metal battery equipped with a lithium-containing negative electrode. Based on the charge / discharge rate information, the system determines the charge / discharge content for the lithium metal battery. The charge / discharge rate information is discharge rate information relating to the discharge rate of the lithium metal battery, The computer is instructed to determine a smaller charging current as the charge / discharge content when the charging rate included in the charge / discharge rate information is less than or equal to a first specified value. program.

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