Charging systems, chargers

Abstract

To provide a charging system and a charger that can keep charging time from becoming long.SOLUTION: A charging system BCS comprises: a charger 120 for a battery module BM containing a lithium-ion battery; and a battery-side device that monitors a battery state including an amount of lithium-ion deposition in the lithium-ion battery. The charger 120 includes: a charging determination unit 122 that determines availability of charging of the battery module BM on the basis of battery information including the battery state acquired from the battery-side device; and a charging control unit 123 that performs charging of the battery module BM on the basis of a determination result of the charging determination unit 122.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present disclosure relates to a charging system and charger for storage batteries, including lithium-ion batteries. [Background technology]

[0002] Conventionally, a known charger for a battery pack including a lithium-ion battery performs a preliminary charge at a current value smaller than the normal charging current for a certain period immediately after the start of charging the battery pack, and judges the charger based on over-discharge (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5400333 Summary of the Invention [Problem to be solved by the invention]

[0004] However, as in Patent Document 1, if the determination of whether charging is possible is made after charging of the storage battery has started, the time required for charging with a charger (i.e., charging time) will be long, which is undesirable because it will lengthen the period during which the storage battery cannot be used and increase the user's waiting time.

[0005] An object of the present disclosure is to provide a charging system and a charger that can prevent charging times from becoming long. [Means for solving the problem]

[0006] The invention described in claim 1 is A battery charging system (BCS), a charger (120) for a storage battery (BM) including a lithium-ion battery; a battery-side device (20, 100) for monitoring the battery state including the amount of lithium deposition in the lithium ion battery; The charger is an information acquisition unit (121) that acquires battery information including the battery state from the battery-side device; a charge determination unit (122) that determines whether or not the storage battery can be charged based on battery information; A charge control unit (123) that charges the storage battery based on the determination result of the charge determination unit. fruit, The battery-side device includes a deposition amount detection unit (37) that detects the amount of lithium deposition, The deposition amount detection unit estimates the amount of lithium deposition from the behavior of current and voltage when both ends of the lithium ion battery are short-circuited, utilizing the correlation between the amount of lithium deposition and the behavior of current and voltage when both ends of the lithium ion battery are short-circuited. .

[0009] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and the specific components described in the embodiments described below. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing a battery pack to which a battery monitoring device according to a first embodiment is applied. [Figure 2] FIG. 1 is an explanatory diagram illustrating a lithium ion battery. [Figure 3] FIG. 2 is a schematic configuration diagram of a battery management unit including a battery monitoring device. [Figure 4] FIG. 2 is an explanatory diagram for explaining a battery monitoring device. [Figure 5] FIG. 2 is an explanatory diagram for explaining a deposition amount detection unit included in the battery monitoring device. [Figure 6] FIG. 10 is an explanatory diagram for explaining a method for calculating the amount of lithium deposition. [Figure 7] FIG. 10 is an explanatory diagram for explaining how to obtain a parasitic resistance value. [Figure 8] FIG. 4 is an explanatory diagram for explaining a flow of calculation of the amount of lithium deposition. [Figure 9] 4 is an explanatory diagram for explaining diagnosis of the deposition amount detection unit by the diagnosis unit. FIG. [Figure 10] FIG. 10 is an explanatory diagram for explaining a method for calculating a volume ratio SOH of a battery. [Figure 11]4 is a timing chart showing changes in output from various sensors before and after an abnormal heat generation phenomenon occurs. [Figure 12] FIG. 2 is an explanatory diagram illustrating the flow of a control process executed by a battery monitoring device. [Figure 13] FIG. 1 is a schematic configuration diagram of a battery management system including a battery monitoring device. [Figure 14] 1 is a schematic configuration diagram of a charging system including a battery monitoring device; [Figure 15] FIG. 4 is an explanatory diagram for explaining current and voltage when a battery module is charged in a charging system that is a comparative example of the first embodiment. [Figure 16] FIG. 4 is an explanatory diagram illustrating the flow of control processing executed by the battery monitoring device when charging of the battery module starts. [Figure 17] FIG. 3 is an explanatory diagram illustrating the flow of a control process executed by a charger. [Figure 18] FIG. 4 is an explanatory diagram illustrating the flow of control processing executed by the battery monitoring device while the battery module is being charged. [Figure 19] 3 is an explanatory diagram for explaining current and voltage when charging a battery module in the charging system of the first embodiment. FIG. [Figure 20] FIG. 1 is a schematic configuration diagram of a battery evaluation system. [Figure 21] FIG. 1 is a schematic block diagram for explaining the value calculation and use proposal of a battery module by a battery evaluation system. [Figure 22] FIG. 2 is an explanatory diagram for explaining rebuild information generated by the battery evaluation system. [Figure 23] 3A to 3C are explanatory diagrams for explaining the manufacturing process up to the stage of mounting the battery pack on a vehicle. [Figure 24] FIG. 10 is an explanatory diagram for explaining some functions of a battery monitoring device according to a second embodiment. [Figure 25] FIG. 2 is an explanatory diagram for explaining the timing at which lithium is precipitated in a lithium ion battery. [Figure 26] FIG. 10 is a schematic configuration diagram of a large-capacity electricity storage system according to a third embodiment. [Figure 27] FIG. 2 is an explanatory diagram for explaining the internal configuration of the large-capacity power storage system. [Figure 28] FIG. 1 is a schematic system configuration diagram of a large-capacity power storage system. [Figure 29] FIG. 11 is an explanatory diagram for explaining temperature control of a large-capacity electricity storage system that is a comparative example of the third embodiment. [Figure 30] FIG. 10 is an explanatory diagram for explaining temperature control of a large-capacity electricity storage system according to a third embodiment. [Figure 31] FIG. 10 is an explanatory diagram for explaining a modified example of temperature control. [Figure 32] FIG. 10 is an explanatory diagram for explaining the best time to replace the battery. [Figure 33] FIG. 2 is an explanatory diagram for explaining the relationship between the charge rate and the temperature and the amount of lithium deposition. [Figure 34] FIG. 10 is a schematic configuration diagram of a battery transportation device according to a fourth embodiment. [Figure 35] FIG. 1 is a schematic system configuration diagram of a battery transportation device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, parts that are the same as or equivalent to those described in the preceding embodiments will be given the same reference numerals, and their description may be omitted. Furthermore, in the embodiments, when only some of the components are described, the components described in the preceding embodiments can be applied to the remaining components. The following embodiments can be partially combined with each other, even if not specifically stated, as long as there is no particular problem with the combination.

[0012] (First embodiment) In this embodiment, first, an example in which the battery monitoring device 20 and battery monitoring method of the present disclosure are applied to a battery management unit (hereinafter also referred to as BMU) of a vehicle equipped with a battery pack 1, which is a high-voltage battery, will be described with reference to Figures 1 to 13. After that, in this embodiment, a charging system BCS and a battery evaluation system BRS including the battery monitoring device 20 will be described.

[0013] The BMU includes a battery pack 1 shown in Figure 1. The battery pack 1 includes a sealed container 11 that forms an outer shell, and the sealed container 11 houses multiple battery modules BM, a battery monitoring device 20, and a battery ECU 100 inside. The sealed container 11 is provided with a high-pressure protection valve HPV for venting gas inside to the outside when the internal pressure increases. In the battery pack 1, each battery module BM is adjusted to an appropriate temperature by a temperature control device (not shown).

[0014] The battery modules BM are connected to electrical equipment such as an electric motor (not shown) for vehicle operation, and are a power source that supplies power to the electrical equipment. The battery modules BM are electrically connected in series. The battery modules BM are also assembled batteries in which a plurality of battery cells C are electrically connected in series. While the present embodiment illustrates a battery pack 1 including three battery modules BM, the number of battery modules BM is not limited to this and can be any number. The number of battery cells C constituting the battery module BM can also be any number. Some of the battery modules BM may be electrically connected in parallel. Hereinafter, the battery cells C and battery modules BM may be simply referred to as batteries. The battery module BM of the present embodiment is a storage battery including lithium-ion batteries.

[0015] Battery cell C is a rechargeable secondary battery. Battery cell C is a lithium-ion battery. For example, as shown in Figure 2, a lithium-ion battery is configured with lithium iron phosphate (LFP) or nickel-manganese-cobalt (NMC) as the positive electrode material and graphite as the negative electrode material. Furthermore, a lithium-ion battery may have a positive electrode current collector made of aluminum and a negative electrode current collector made of copper. While lithium-ion batteries configured in this way have excellent charge / discharge cycle characteristics, their electrode potential is very close to the lithium deposition potential, making lithium deposition easy in the charged state.

[0016] As shown in FIG. 3 , the battery monitoring device 20 is electrically connected to each battery module BM via a connection member 21. The connection member 21 includes a flexible substrate FPC on which a wiring pattern is printed. The battery monitoring device 20 includes the same number of sensor units 30A, 30B, and 30C as the battery modules BM, and the same number of monitoring modules 50A, 50B, and 50C as the battery modules BM. Because the sensor units 30A, 30B, and 30C have the same basic configuration, they will not be described individually but will be described collectively as the sensor unit 30. Furthermore, because the monitoring modules 50A, 50B, and 50C have the same basic configuration, they will not be described individually but will be described collectively as the monitoring module 50.

[0017] The sensor unit 30 detects the battery status of each battery module BM. As shown in FIG. 4, the sensor unit 30 includes a temperature sensor 31, a current sensor 32, a voltage sensor 33, a strain sensor 34, a gas sensor 35, a pack internal pressure sensor 36, a deposition amount detection unit 37, and a coating detection unit 38. At least some of the various sensors that make up the sensor unit 30 are mounted on a flexible substrate FPC. Note that it is not necessary for all of the various sensors that make up the sensor unit 30 to be mounted on the flexible substrate FPC. However, since it is preferable that the temperature sensor 31, strain sensor 34, and gas sensor 35 be located near the battery cells C, it is desirable to mount them on the flexible substrate FPC.

[0018] The temperature sensor 31 is a sensor that detects the battery temperature of the lithium-ion batteries. As shown in FIG. 1, multiple temperature sensors 31 are mounted on the flexible printed circuit board FPC. The number of temperature sensors 31 mounted on the flexible printed circuit board FPC is equal to or slightly less than the number of battery cells C so that the battery temperatures of all lithium-ion batteries that make up the battery module BM can be determined. The battery temperature may be estimated from the measurement results of the internal impedance of the battery cells C. In this case, the means for estimating the battery temperature functions as the temperature sensors 31.

[0019] The current sensor 32 is a sensor that detects the current flowing through the battery module BM. When the battery modules BM are electrically connected in series, one current sensor 32 per battery pack 1 is sufficient.

[0020] The voltage sensor 33 is capable of detecting the voltage of the battery module BM as a block voltage in addition to detecting the cell voltage of each battery cell C. The voltage sensor 33 can be configured, for example, as a flying capacitor type circuit that sequentially charges a capacitor with the cell voltage of each battery cell C and detects the voltage between the terminals of the capacitor as the cell voltage.

[0021] The strain sensor 34 is a sensor that detects strain in each battery cell C caused by gas generation or the like inside each battery cell C. Note that the strain in the battery cell C may be detected by another sensor, such as an ultrasonic sensor, instead of the strain sensor 34.

[0022] The gas sensor 35 is a sensor for detecting gas leakage from each battery cell C. The gas sensor 35 is configured to be able to detect at least one of hydrogen, carbon monoxide, carbon dioxide, and hydrogen fluoride, which are generated when an abnormality occurs in the lithium ion battery, for example.

[0023] The pack internal pressure sensor 36 is a sensor that detects the pressure inside the sealed container 11 of the battery pack 1 as the pack internal pressure. The pack internal pressure sensor 36 is configured, for example, as an atmospheric pressure range type pressure sensor that uses atmospheric pressure as a reference.

[0024] The deposition amount detection unit 37 is a device that detects lithium deposition in a lithium ion battery. The deposition amount detection unit 37 utilizes the correlation between the amount of lithium deposition in a lithium ion battery and the behavior of current and voltage when both ends of the lithium ion battery are short-circuited, and estimates the amount of lithium deposition from the behavior.

[0025] 5, the deposition amount detection unit 37 has a short circuit 371 that temporarily shorts both ends of the lithium ion battery to discharge it, and a calculator 372 that estimates the amount of lithium deposition based on the behavior of the current and voltage when the lithium ion battery is shorted by the short circuit 371. The short circuit 371 is mounted on a flexible printed circuit (FPC). The calculator 372 is also mounted on the monitoring module 50.

[0026] Although not shown, short circuit 371 has a short-circuit switch for short-circuiting both ends of the lithium-ion battery, a coil, and a capacitor. The internal resistance of the lithium-ion battery, and the coil and capacitor of short circuit 371 form a self-resonant circuit.

[0027] When both ends of the lithium ion battery are short-circuited, the calculator 372 extracts a resistance change component that is correlated with the amount of lithium deposition contained in the signal waveform of at least one of the current and voltage flowing through the short circuit 371, and calculates an estimated value of the amount of lithium deposition from the extracted component.

[0028] The above estimation method has a very simple configuration and is a very useful method in that it can detect a specific battery degradation mode by adjusting the discharge frequency from the lithium-ion battery.

[0029] On the other hand, the internal resistance of a lithium ion battery is on the order of several mΩ to several hundred mΩ, and is easily affected by disturbances such as temperature and parasitic impedance, so it has been found that it is difficult to accurately determine the amount of lithium deposition using the above estimation method. This fact was discovered after extensive research by the present inventors.

[0030] Taking this into consideration, the calculator 372 of the deposition amount detection unit 37 calculates the lithium deposition amount as a corrected value obtained by correcting the above estimated value using both the battery temperature detected by the temperature sensor 31 and the parasitic resistance value pre-stored in the memory unit 51 of the monitoring module 50, as shown in Figure 6.

[0031] The parasitic resistance value is part of the parasitic impedance occurring between the lithium ion battery and the short circuit 371. The parasitic resistance value changes depending on the battery temperature. Therefore, the calculator 372 corrects the parasitic resistance value stored in the memory unit 51 depending on the battery temperature, and calculates the amount of lithium deposition using the corrected parasitic resistance value. In addition to functioning as a means for estimating the amount of lithium deposition, the calculator 372 also functions as a calibration means for correcting the estimated value of the amount of lithium deposition.

[0032] Here, the parasitic resistance value is determined by connecting the deposition amount detection unit 37 to a calibration device CD having a known impedance Z before connecting it to the lithium ion battery, as shown in Fig. 7. Specifically, as shown in Fig. 8, a short circuit 371 is connected to the calibration device CD, and the parasitic resistance value is determined in this state. The parasitic resistance value is then stored in the memory unit 51 of the monitoring module 50. Next, the short circuit 371 is connected to the battery module BM, and the amount of lithium deposition is calculated in this state.

[0033] The deposition amount detection unit 37 configured in this manner can ensure robustness against parasitic impedance and temperature changes, which is very effective in detecting the amount of deposited lithium with high accuracy.

[0034] The short circuit 371 of this embodiment includes a coil, which increases its size. Therefore, it is necessary to appropriately miniaturize it in consideration of mountability. Miniaturization can be achieved, for example, by improving the saturation magnetic flux density of the coil. Specific means for miniaturization include, for example, using a coil made of a material with high magnetic flux density, or improving the saturation magnetic flux density by providing a gap.

[0035] The film detection unit 38 detects the thickness of the film formed at the interface between the negative electrode and the electrolyte when the lithium-ion battery is being charged. This film is also called the SEI layer. SEI is an abbreviation for Solid Electrolyte Interphase.

[0036] The thickness of the SEI layer correlates with the behavior of the current and voltage when both ends of the lithium-ion battery are short-circuited by the short circuit 371. The film detection unit 38 estimates the thickness of the SEI layer from the behavior of the current and voltage when both ends of the lithium-ion battery are short-circuited by the short circuit 371. Specifically, when both ends of the battery are short-circuited by the short circuit 371, the film detection unit 38 extracts a component that correlates with the thickness of the SEI layer from the signal waveform of at least one of the current and voltage flowing through the short circuit 371, and estimates the thickness of the SEI layer from the extracted component. Note that when detecting the thickness of the SEI layer, it is desirable to correct for the battery temperature, as with the detection of the amount of lithium deposition.

[0037] Here, the amount of lithium deposition and the thickness of the SEI layer are physical quantities that are more highly correlated with battery capacity degradation than the battery voltage and current. In this embodiment, the deposition amount detection unit 37 and the film detection unit 38 constitute a "degradation detection unit" that detects physical quantities that are more highly correlated with battery capacity degradation than the battery voltage and current. Furthermore, the amount of lithium deposition is one of the factors that can lead to abnormal heat generation, which is a continuous, unintended rise in battery temperature. For this reason, the deposition amount detection unit 37 constitutes a "factor monitoring unit" that monitors factors that can lead to abnormal heat generation.

[0038] 4, a battery state detection unit 39 that detects the battery state is mounted on the flexible substrate FPC. The battery state detection unit 39 detects a battery state in which the battery temperature rises excessively, a battery state in which the battery is overcharged, a battery state in which the internal resistance changes significantly, etc., based on the sensor outputs of the temperature sensor 31, the current sensor 32, and the voltage sensor 33, for example.

[0039] Next, we will explain the monitoring module 50. The monitoring module 50 is a satellite module that is directly attached to the battery module BM. The monitoring module 50 is a device on the high-voltage side of the BMU. The monitoring module 50 is electrically connected to the battery and constitutes an "abnormality detection unit" that detects abnormalities in the battery.

[0040] The monitoring module 50 includes a storage unit 51, a wireless communication unit 52, an internal resistance detection unit 53, a monitoring IC 54, etc. The storage unit 51 stores various information such as a unique ID set for each monitoring module 50, the monitoring results of the battery module BM, the parasitic resistance value described above, etc. The storage unit 51 is configured as a non-transient tangible storage medium.

[0041] The wireless communication unit 52 is a communication device that enables two-way communication with the battery ECU 100. The monitoring module 50 receives various signals from the battery ECU 100 and transmits the monitoring results of the monitoring module 50 to the battery ECU 100.

[0042] The internal resistance detection unit 53 is a device that detects the internal resistance of the battery based on various information output from the sensor unit 30. Furthermore, changes in the internal resistance of the battery are one of the factors that can lead to abnormal heat generation. For this reason, the internal resistance detection unit 53 constitutes a "factor monitoring unit" that monitors factors that can lead to abnormal heat generation.

[0043] The monitoring IC 54 is electrically connected to the battery and detects abnormalities in the battery. The monitoring IC 54 prevents abnormal heat generation from occurring based on the results of monitoring factors that lead to the abnormal heat generation, detects abnormal conditions that occur in the battery in the early stages of the abnormal heat generation, and implements measures to address the abnormal heat generation based on the results of the abnormal condition detection.

[0044] The monitoring IC 54 includes an ASIC circuit having an algorithm that performs at least part of the monitoring of factors that lead to abnormal heat generation and the detection of abnormal conditions that occur in the battery at the early stage of the abnormal heat generation phenomenon. Specifically, the monitoring IC 54 is configured to have a diagnostic unit 541, an SOH estimation unit 542, and a monitoring control unit 543 as functional units that perform various controls.

[0045] Since the amount of lithium deposition is a parameter that greatly affects the residual value of the battery, it is also important to verify the accuracy of this parameter. The diagnosis unit 541 compares a predetermined battery state estimated from the amount of lithium deposition with a battery state estimated from factors other than the amount of lithium deposition, and diagnoses the suitability of the deposition amount detection unit 37.

[0046] 9, the diagnosis unit 541 estimates the battery volume ratio SOH from the amount of lithium deposition detected by the deposition amount detection unit 37. The diagnosis unit 541 also estimates the battery volume ratio SOH based on the sensor outputs of the temperature sensor 31, the current sensor 32, and the voltage sensor 33. SOH is an abbreviation for State of Health.

[0047] Next, the diagnosis unit 541 compares the volumetric rate SOH estimated from the amount of lithium deposition with the volumetric rate SOH estimated from the battery's temperature, current, and voltage using a state comparator to diagnose the appropriateness of the deposition amount detection unit 37. For example, the diagnosis unit 541 diagnoses the deposition amount detection unit 37 as appropriate if the difference between the volumetric rate SOH estimated from the amount of lithium deposition and the volumetric rate SOH estimated from the battery's temperature, current, and voltage is within a predetermined range. On the other hand, the diagnosis unit 541 diagnoses the deposition amount detection unit 37 as inappropriate if the difference between the volumetric rate SOH estimated from the amount of lithium deposition and the volumetric rate SOH estimated from the battery's temperature, current, and voltage exceeds a predetermined range. If the deposition amount detection unit 37 is diagnosed as inappropriate, the monitoring IC 54 prohibits detection of the amount of lithium deposition and control processing using the amount of lithium deposition, or transmits a signal indicating a failure of the deposition amount detection unit 37 to the battery ECU 100 via the wireless communication unit 52. In this embodiment, the battery volume ratio SOH is exemplified as the battery state estimated by the diagnosing unit 541, but the diagnosing unit 541 may be configured to estimate a battery state other than the volume ratio.

[0048] Japanese Patent Application Laid-Open Publication No. 2014-102076 discloses a method for calculating the full charge capacity of a battery. In this calculation method, the change in charge / discharge capacity between a first time point and a second time point is calculated by integrating the current value of the battery's output current over time. Then, the OCV is measured at the first time point and the second time point, and the remaining capacity SOC at the first time point and the second time point is calculated using the SOC-OCV curve. A change ΔSOC is calculated as the deviation of the remaining capacity SOC at each time point. Next, the full charge capacity of the battery is calculated by dividing the change in charge / discharge capacity by the change ΔSOC in the remaining capacity SOC. The battery's volumetric capacity ratio SOH is also calculated by dividing the full charge capacity of the battery by the initial full charge capacity value.

[0049] However, the above-described method for calculating the remaining capacity SOC and the volumetric capacity ratio SOH has problems in practicality because it cannot calculate the charge / discharge amount of the battery unless a certain amount of charge or discharge occurs, in order to avoid the influence of errors in the current sensor 32 and the voltage sensor 33. In addition, there is a problem in that when calculating the charge / discharge amount, the offset error of the current sensor 32 causes the calculation error of the volumetric capacity ratio SOH to increase over time.

[0050] Taking these factors into consideration, the SOH estimation unit 542 estimates the battery's volume ratio SOH based on a physical quantity that has a higher correlation with battery capacity degradation than the battery's voltage and current. The SOH estimation unit 542 constitutes a "volume ratio estimation unit."

[0051] One of the causes of battery degradation is an increase in the battery's internal resistance. The internal resistance of a battery is strongly correlated with physical quantities such as the amount of lithium deposition and the internal resistance of the battery. The internal resistance of a battery is also temperature-dependent and affects the current and voltage of the battery.

[0052] Taking these factors into consideration, the SOH estimation unit 542 of this embodiment estimates the volumetric capacity SOH using an estimation model for the volumetric capacity SOH based on the amount of lithium precipitation, the thickness of the SEI layer, the battery temperature, the current, and the voltage, as shown in Fig. 10. The estimation model for the volumetric capacity SOH is, for example, a control map or function that defines the relationship between the volumetric capacity SOH, the amount of lithium precipitation, the thickness of the SEI layer, the battery temperature, the current, and the voltage. Note that the estimation model may be, for example, a model obtained by deep learning using a neural network, reinforcement learning, or deep reinforcement learning.

[0053] This enables real-time diagnosis of the battery condition, which was previously difficult when estimating the volumetric capacity SOH based on the charge / discharge amount. In addition, by accurately measuring the temperature, the influence of temperature on the battery's internal resistance can be eliminated, and deterioration information can be appropriately extracted, improving accuracy.

[0054] The monitoring control unit 543 prevents the occurrence of abnormal heat generation phenomena based on the results of monitoring factors that lead to the abnormal heat generation phenomena, detects abnormal conditions that occur in the battery at the early stage of the abnormal heat generation phenomena, and implements measures against the abnormal heat generation phenomena based on the results of the detection of the abnormal conditions. Although not shown, the monitoring IC 54 controls a circuit that equalizes the voltages of multiple battery cells C.

[0055] Next, a description will be given of the battery ECU 100. The battery ECU 100 is a main module in the BMU, and controls the charging and discharging of each battery module BM. The battery ECU 100 is a device on the low-voltage side in the BMU.

[0056] Specifically, the battery ECU 100 is configured as a microcomputer equipped with a processor, memory, I / O, wireless communication device 110, etc. The battery ECU 100 is configured to be able to communicate with each of the monitoring modules 50A, 50B, and 50C via the wireless communication device 110. The battery ECU 100 is also connected to various ECUs via a communication path such as a CAN. Examples of the various ECUs include a thermal management ECU that controls the temperature regulator of the battery, and an ECU for an HMI device mounted on the vehicle. The battery ECU 100 is capable of reporting various battery conditions to the outside via the HMI device, etc.

[0057] The battery pack 1 configured as described above includes a rechargeable battery such as a lithium-ion battery. This type of battery can experience an abnormal heat generation phenomenon in which a specific component inside the battery heats up due to some trigger, which then causes other components to heat up, resulting in an unintended continuous rise in the battery temperature. This abnormal heat generation phenomenon is undesirable because it significantly reduces the thermal reliability of the battery. Therefore, it is important to detect the presence or absence of abnormal heat generation in lithium-ion batteries and other batteries to ensure their thermal reliability.

[0058] Here, the changes in output from various sensors before and after an abnormal heat generation phenomenon will be described with reference to Fig. 11. Fig. 11 shows an example of the results of verification conducted by the present inventors on the changes in output from various sensors before and after an abnormal heat generation phenomenon.

[0059] 11, before the occurrence of abnormal heat generation, the first sign of a battery abnormality is a change in the volume of the battery due to an increase in gas pressure inside the battery cell, which causes the output of the strain sensor 34 to tend to increase.

[0060] After that, as the change in the battery volume becomes larger, the battery breaks down and gas inside the battery cell starts to leak, causing the output of the gas sensor 35 to tend to increase. When the battery breaks down, the gas pressure inside the battery decreases, causing the output of the strain sensor 34 to tend to decrease.

[0061] Furthermore, although not shown in FIG. 11, as the battery deteriorates, lithium deposition occurs inside the battery and the thickness of the SEI layer increases, which increases the internal resistance of the battery.

[0062] When an abnormal heat generation phenomenon occurs, the battery temperature and the pressure inside the battery pack 1 (i.e., the pack internal pressure) rise sharply, and the battery voltage drops sharply. Furthermore, the output of the gas sensor 35 tends to increase. These symptoms become noticeable in the early stages of the abnormal heat generation phenomenon.

[0063] Taking these factors into consideration, the battery monitoring device 20 executes control processing to prevent and detect abnormal heat generation phenomena at an early stage. An example of the control processing executed by the battery monitoring device 20 will now be described with reference to FIG.

[0064] 12 is executed by the battery monitoring device 20 periodically or irregularly, for example, while the vehicle is running and during a period until a predetermined time has elapsed since the vehicle was stopped. Note that each process shown in this flowchart is realized by a respective functional unit of the battery monitoring device 20. Furthermore, each step that realizes this process can also be understood as each step that realizes a battery monitoring method.

[0065] 12 , in step S100, the battery monitoring device 20 reads various signals from the sensor unit 30 and the like. Then, in step S105, the battery monitoring device 20 determines whether or not an abnormal heat generation phenomenon has occurred. As described above, in the early stages of an abnormal heat generation phenomenon, the battery temperature, pack internal pressure, and output of the gas sensor 35 rise sharply, and the battery voltage drops sharply. Taking this into consideration, the battery monitoring device 20 determines whether or not an abnormal heat generation phenomenon has occurred based on the sensor outputs of at least some of the temperature sensor 31, voltage sensor 33, gas sensor 35, and pack internal pressure sensor 36.

[0066] When the occurrence of an abnormal heat generation phenomenon is detected, the battery monitoring device 20 proceeds to step S110 and implements measures to deal with the abnormal heat generation phenomenon. These measures include an external notification process that notifies the outside of the occurrence of the abnormal heat generation phenomenon, and a battery protection process that involves at least one of cooling the battery and controlling charging and discharging the battery.

[0067] In the external notification process, for example, a signal indicating the occurrence of an abnormal heat generation phenomenon is output to the battery ECU 100, and an equipment with a notification function such as an HMI device is operated via the battery ECU 100 to notify the user and battery manager of the occurrence of the abnormal heat generation phenomenon.

[0068] In the battery protection process, for example, a signal instructing the battery ECU 100 to cool the battery is output, and the battery temperature control device is operated via the battery ECU 100 to cool the battery. Such battery cooling can slow the progression of abnormal heat generation in the battery. In addition, in the battery protection process, for example, a signal instructing the battery ECU 100 to limit battery charging and discharging is output, and battery operation is limited to suppress self-heating of the battery. Such charge and discharge control can also slow the progression of abnormal heat generation in the battery. The battery protection process constitutes an extension process that extends the life of the battery.

[0069] As one of the measures against the abnormal heat generation phenomenon, the battery monitoring device 20 identifies an abnormal cell among the multiple battery cells C as an abnormal cell based on at least one of the monitoring results of each of the multiple battery cells C and the detection results of the abnormal state of the battery. This makes it possible to restrict the use of the abnormal cell and slow down the progression of the abnormal heat generation phenomenon.

[0070] Countermeasures against abnormal heat generation are not limited to the above-mentioned processes and may be implemented by processes other than those described above.Countermeasures against abnormal heat generation may include, for example, turning on a warning light or sounding an alarm.

[0071] On the other hand, if the occurrence of an abnormal heat generation phenomenon is not detected, the battery monitoring device 20 proceeds to the processing of step S115 and subsequent steps. Note that the processing of step S115 and subsequent steps is processing for preventing the occurrence of an abnormal heat generation phenomenon in advance.

[0072] In step S115, the battery monitoring device 20 determines whether battery overcharging has been detected. Battery overcharging can be detected, for example, by monitoring the sensor output of the voltage sensor 33. If battery overcharging is detected, the battery monitoring device 20 executes a charge suppression process in step S120 and returns to step S115. This charge suppression process suppresses battery charging and / or discharges the battery.

[0073] If battery overcharging is not detected, the battery monitoring device 20 determines in step S125 whether or not an excessive temperature rise of the battery has been detected. An excessive temperature rise of the battery can be detected, for example, by monitoring the sensor output of the temperature sensor 31. If an excessive temperature rise of the battery is detected, the battery monitoring device 20 implements output limitation and cooling control in step S130, and returns to step S115. Output limitation, for example, suppresses battery charging and discharging. Cooling control, for example, cools the battery using a battery temperature adjustment device.

[0074] If an excessive temperature rise of the battery is not detected, the battery monitoring device 20 determines whether new lithium deposition has been detected in step S135. Lithium deposition can be detected, for example, by monitoring the increase in the amount of lithium deposition detected by the deposition amount detection unit 37.

[0075] If new lithium deposition is detected, the battery monitoring device 20 performs charging, regeneration control, and heating control in step S140, and then returns to step S115. In charging and regeneration control, for example, battery charging is suppressed. In heating control, for example, the battery is heated by a battery temperature control device. Note that the processes performed when lithium deposition is detected constitute extension processes for extending the battery life.

[0076] If no new lithium deposition is detected, the battery monitoring device 20 determines whether a change in the internal resistance of the battery has been detected in step S145. The internal resistance of the battery can be detected, for example, by monitoring the increase in the internal resistance detected by the internal resistance detection unit 53.

[0077] If a change in the battery's internal resistance is detected, the battery monitoring device 20 performs battery output limitation, temperature control, and notification of the degree of deterioration in step S150, and then returns to step S115. For example, output control involves suppressing battery discharge. For example, temperature control involves adjusting the battery temperature using a temperature control device to maintain the battery temperature within an appropriate range. For notification of the degree of deterioration, the degree of deterioration of the battery is determined from the battery's internal resistance, and the result of the degree of deterioration determination or the time to replace the battery estimated from the determination result is notified to the outside. Note that the various processes performed when a change in internal resistance is detected constitute extension processes for extending the life of the battery.

[0078] If no change in the internal resistance of the battery is detected, the battery monitoring device 20 determines whether or not deformation of the battery is detected in step S155. Deformation of the battery can be detected by monitoring the sensor output amount of the strain sensor 34.

[0079] If battery deformation is detected, the battery monitoring device 20 limits the battery output in step S160, and returns to step S115. The output control involves, for example, restricting the charging and discharging of the battery.

[0080] If no deformation of the battery is detected, it is considered that there are no signs of an abnormal heat generation phenomenon and that the battery is in a normal state. Therefore, if no deformation of the battery is detected, the battery monitoring device 20 ends the control process shown in Figure 12.

[0081] With the rapid electrification of vehicles, a large amount of used batteries is expected to be generated in the near future. Because battery manufacturing involves the emission of large amounts of CO2 and the use of rare metals, it is expected that used batteries will be reused, rebuilt, or recycled depending on the battery's remaining capacity (SOC) and volumetric capacity (SOH), creating a battery ecosystem that is suited to a circular economy. To build such a battery ecosystem, it is important to accurately assess the value of batteries, including their remaining capacity (SOC) and volumetric capacity (SOH). Furthermore, after their in-vehicle use is terminated, batteries are expected to be stored until a secondary use is determined. However, batteries continue to discharge even when not in use, and depending on the storage conditions, they may deteriorate. Therefore, secondary users need to know the remaining capacity (SOC) and volumetric capacity (SOH) of the battery at that moment, making real-time battery diagnosis essential.

[0082] As described above, the battery monitoring device 20 of this embodiment can calculate the remaining capacity SOC and the volumetric capacity ratio SOH in real time. Considering this, it is desirable to treat the battery module BM and the battery monitoring device 20 as a battery unit UT, and distribute the battery module BM in units of the battery unit UT. It is also desirable to manage the battery module BM by, for example, a battery management system BMS shown in FIG. 13.

[0083] The battery management system BMS includes a battery monitoring device 20 attached to the battery module BM and a battery management device 60. The battery management device 60 includes a performance determination unit 61, a value setting unit 62, and a performance notification unit 63.

[0084] The performance determination unit 61 determines whether the battery can be reused secondary, based on the volumetric capacity SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20. For example, the performance determination unit 61 determines that the battery can be reused secondary if the volumetric capacity SOH estimated by the SOH estimation unit 542 is equal to or greater than a predetermined value, and determines that the battery cannot be reused secondary if the volumetric capacity SOH estimated by the SOH estimation unit 542 is less than the predetermined value. Note that the performance determination unit 61 may also determine whether the battery can be reused secondary based on a battery state other than the volumetric capacity SOH.

[0085] The value setting unit 62 determines whether or not there is a battery abnormality based on the floor area ratio SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20, and sets the battery residual value if there is a battery abnormality. For example, the value setting unit 62 estimates the battery residual value lower as the floor area ratio SOH decreases. Note that the value setting unit 62 may also be configured to set the battery residual value based on a battery condition other than the floor area ratio SOH.

[0086] The performance notification unit 63 determines whether the volumetric capacity SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20 is within the allowable range of the volumetric capacity SOH indicated in the battery specification data, and outputs the result of this determination to the outside.

[0087] The performance notification unit 63 acquires battery specification data provided by the battery manufacturer or the like and stores it in memory. Then, for example, if the volumetric capacity SOH estimated by the SOH estimation unit 542 is within the allowable range indicated in the specification data, the performance notification unit 63 notifies the battery distributor, secondary user, etc. of this fact. Furthermore, for example, if the volumetric capacity SOH estimated by the SOH estimation unit 542 is outside the allowable range indicated in the specification data, the performance notification unit 63 notifies the battery distributor, secondary user, etc. of the fact that secondary reuse of the battery is difficult.

[0088] The battery monitoring device 20 and the battery monitoring method described above can effectively take measures against abnormal heat generation, effectively detect the amount of lithium deposition, and effectively estimate the volume ratio SOH. Specifically, this is as follows.

[0089] [Countermeasures against abnormal heat generation] The battery monitoring device 20 and the battery monitoring method monitor factors that lead to abnormal heat generation and prevent the occurrence of abnormal heat generation based on the results of monitoring the factors. In addition, the battery monitoring device 20 and the battery monitoring method detect abnormal conditions occurring in the battery at the early stage of the abnormal heat generation phenomenon and implement countermeasures against the abnormal heat generation phenomenon based on the results of the abnormal condition detection. This makes it possible to implement effective heat countermeasures, preventing the occurrence of abnormal heat generation phenomenon and implementing countermeasures from the early stage of the abnormal heat generation phenomenon, even if the abnormal heat generation phenomenon does occur.

[0090] In addition, the battery monitoring device 20 provides the following effects.

[0091] (1) The monitoring module 50 of the battery monitoring device 20 monitors factors that lead to abnormal heat generation and detects abnormal battery conditions in parallel. In other words, the monitoring module 50 detects abnormal battery conditions regardless of the results of monitoring factors that lead to abnormal heat generation. This allows for earlier detection of abnormal conditions compared to, for example, monitoring factors that lead to abnormal heat generation and then detecting the abnormal condition, and therefore allows for earlier implementation of measures against the abnormal heat generation.

[0092] (2) Measures to be taken when an abnormal heat generation phenomenon occurs include an external notification process that notifies the outside of the occurrence of the abnormal heat generation phenomenon, or a battery protection process that involves at least one of temperature regulation control and charge / discharge control of the battery. When the measures to be taken when an abnormal heat generation phenomenon is included in the external notification process, in addition to measures that the battery monitoring device 20 itself can take, it becomes easier to implement measures by devices external to the battery monitoring device 20 or measures in cooperation with external devices. Furthermore, when the measures to be taken when an abnormal heat generation phenomenon is included in the battery protection process, it becomes possible to appropriately protect the battery.

[0093] (3) The monitoring module 50 performs a process to extend the battery life in accordance with the results of monitoring factors that lead to abnormal heat generation. In this way, by performing a process to extend the battery life in accordance with the results of monitoring factors that lead to abnormal heat generation, it is possible to appropriately extend the battery life.

[0094] (4) Factors that lead to abnormal heat generation include at least one of lithium deposition inside the battery and the battery's internal resistance. Lithium deposition inside a lithium-ion battery or an increase in internal resistance can lead to abnormal heat generation in the battery. Therefore, monitoring lithium deposition and internal resistance can help prevent abnormal heat generation in the battery.

[0095] (5) The monitoring module 50 identifies an abnormal cell among the multiple battery cells C as an abnormal cell based on at least one of the monitoring results for each of the multiple battery cells C and the detection results for the abnormal state of the multiple battery cells C. In this way, if the configuration is such that an abnormal cell can be identified from among the multiple battery cells C, it becomes possible, for example, to restrict the use of the abnormal cell, thereby preventing the occurrence of an abnormal heat generation phenomenon or delaying the progression of the abnormal heat generation phenomenon.

[0096] (6) The monitoring module 50 is configured to be able to detect at least one of the following abnormal battery conditions: abnormal internal pressure of the sealed container 11, abnormal battery temperature, abnormal battery voltage, and abnormal gas inside the sealed container 11. In the early stages of an abnormal heat generation phenomenon, the internal pressure of the sealed container 11 that houses the battery, the battery temperature, the battery voltage, and the gas state inside the sealed container 11 become abnormal. For this reason, if the monitoring module 50 is configured to be able to detect at least one of the following abnormal internal pressure of the sealed container 11, abnormal battery temperature, abnormal battery voltage, and abnormal gas inside the sealed container 11, it becomes easier to detect an abnormal heat generation phenomenon in the early stages of its occurrence.

[0097] (7) The battery monitoring device 20 includes an ASIC circuit with an algorithm that performs at least part of the monitoring of factors that lead to abnormal heat generation and the detection of abnormal battery conditions. This allows for the monitoring of factors that lead to abnormal heat generation and the detection of abnormal conditions to be achieved with a simple configuration.

[0098] (8) The monitoring module 50 is configured to determine the degree of battery degradation based on the results of monitoring factors that lead to abnormal heat generation, and to externally notify the results of the degradation determination or the estimated time for battery replacement based on the determination results. In this way, a dedicated device for determining the degree of battery degradation is not required. This contributes to simplifying the battery monitoring device 20.

[0099] (9) The connection member 21 that connects the battery and the monitoring module 50 includes a flexible substrate FPC on which a portion of the sensor unit 30 is mounted. In this way, by mounting a portion of the sensor unit 30 on the flexible substrate FPC that constitutes the connection member 21, factors that lead to abnormal heat generation in the battery can be monitored at a position close to the battery.

[0100] [Detection of lithium deposition amount] The deposition amount detection unit 37 of the battery monitoring device 20 calculates an estimate of the amount of lithium deposition based on a change in at least one of the current and voltage when both ends of the lithium ion battery are short-circuited by the short circuit 371. The deposition amount detection unit 37 then corrects the estimate of the amount of lithium deposition based on the battery temperature. This reduces the effect of the battery temperature on the estimate of the amount of lithium deposition, improving the detection accuracy of the amount of lithium deposition, and ensuring the reliability of the deposition amount detection unit 37.

[0101] Furthermore, the deposition amount detection unit 37 corrects the estimated value of the amount of deposited lithium with the parasitic resistance value stored in the storage unit 51. This reduces the influence of the parasitic impedance included in the estimated value of the amount of deposited lithium, improving the detection accuracy of the amount of deposited lithium, and therefore ensuring the reliability of the deposition amount detection unit 37.

[0102] (1) Specifically, the deposition amount detection unit 37 corrects the parasitic resistance value stored in the storage unit 51 in accordance with the battery temperature, and calculates the amount of lithium deposition using the corrected parasitic resistance value. This reduces the influence of the battery temperature and parasitic impedance included in the estimated value of the amount of lithium deposition, thereby improving the detection accuracy of the amount of lithium deposition.

[0103] (2) The parasitic resistance value is determined by connecting the short circuit 371 to a calibration device CD having a known impedance Z before connecting it to the lithium ion battery. This allows the parasitic resistance value of the deposition amount detection unit 37 to be determined with high accuracy. This greatly contributes to improving the detection accuracy of the amount of lithium deposition.

[0104] (3) The battery monitoring device 20 includes a diagnostic unit 541 that compares a predetermined battery state estimated from the amount of lithium deposition with a predetermined battery state estimated from factors other than the amount of lithium deposition to diagnose the suitability of the deposition amount detection unit 37. This allows the diagnostic unit 541 to diagnose the reliability of the deposition amount detection unit 37, ensuring the reliability of the deposition amount detection unit 37.

[0105] [Modification of the battery monitoring device 20] The battery monitoring device 20 may not be the same as the one described above, and may be partially different from the one described above. Furthermore, the technical matters described above can be applied to devices and systems other than in-vehicle devices.

[0106] [Estimation of floor area ratio SOH] The battery monitoring device 20 detects a physical quantity that has a higher correlation with battery capacity degradation than the battery voltage and current, and estimates the battery's volumetric capacity SOH based on that physical quantity. Estimating the volumetric capacity SOH using a physical quantity that has a higher correlation with battery capacity degradation in this way reduces the need to avoid the influence of errors compared to determining the volumetric capacity SOH from the battery's current and voltage, and therefore allows the volumetric capacity SOH to be estimated in a short time. Therefore, the battery monitoring device 20 of the present invention makes it possible to grasp the battery state in a practical manner.

[0107] (1) Here, the amount of lithium deposition and the thickness of the SEI layer are physical quantities that directly affect the capacity degradation of a battery. Therefore, by detecting the amount of lithium deposition and the thickness of the SEI layer and calculating the volumetric capacity SOH based on the amount of lithium deposition and the thickness of the SEI layer, real-time measurement can be ensured. In addition, the degree of cracking of the positive electrode active material inside the battery is a physical quantity that directly affects the capacity degradation of the battery. Therefore, the accuracy of detecting the volumetric capacity SOH can be improved by calculating the volumetric capacity SOH based not only on the amount of lithium deposition and the thickness of the SEI layer but also on the degree of cracking of the positive electrode active material. Note that the degree of cracking of the positive electrode active material can be estimated based on the behavior of the current and voltage when both ends of a lithium-ion battery are short-circuited, or on the sensor output of a strain sensor or ultrasonic sensor.

[0108] (2) The amount of lithium precipitation and the thickness of the SEI layer in a lithium ion battery are correlated with the behavior of the current and voltage when both ends of the lithium ion battery are short-circuited. Taking this into consideration, the battery monitoring device 20 calculates at least one of the amount of lithium precipitation and the thickness of the SEI layer based on the change in at least one of the current and voltage when both ends of the lithium ion battery are short-circuited by the short circuit 371.

[0109] (3) Specifically, the battery monitoring device 20 corrects at least one of the amount of lithium precipitation and the thickness of the SEI layer based on the battery temperature. This reduces the influence of battery temperature on the estimated amount of lithium precipitation and the thickness of the SEI layer, thereby improving the accuracy of detecting the amount of lithium precipitation and the thickness of the SEI layer.

[0110] (4) The battery management system BMS determines whether a battery can be reused based on the volumetric capacity SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20. This makes it easier to determine whether to reuse, rebuild, or recycle a battery when reusing it. This contributes greatly to the creation of a battery ecosystem that is suited to a recycling-oriented society.

[0111] (5) The battery management system BMS determines whether there is a battery abnormality based on the volumetric capacity SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20, and sets the residual value of the battery if there is a battery abnormality. This also makes it easier to determine whether to reuse, rebuild, or recycle when reusing batteries, thereby contributing to the creation of a battery ecosystem adapted to a recycling-oriented society.

[0112] (6) The battery management system BMS determines whether the volumetric capacity SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20 is within the allowable volumetric capacity SOH range indicated in the battery specification data, and outputs the result of this determination to the outside. This also makes it easier to determine whether to reuse, rebuild, or recycle when reusing batteries, greatly contributing to the construction of a battery ecosystem adapted to a recycling-oriented society.

[0113] [Modification of battery management system BMS] The battery management system BMS may not be the same as the one described above, and may be partially different from the one described above. In addition, the technical matters described above can be applied to devices and systems other than in-vehicle devices.

[0114] This concludes the explanation of the BMU, etc. Below, we will explain the charging system BCS and the battery evaluation system BRS.

[0115] [BCS Charging System] The charging system BCS will be described below with reference to Figures 14 to 19. The charging system BCS is a system that charges the battery module BM included in the battery pack 1. The charging system BCS is applied to, for example, a charging station for a vehicle.

[0116] 14, the charging system BCS includes a battery monitoring device 20, a battery ECU 100, a charger 120, and a charging cable CC. In this embodiment, the battery monitoring device 20 and the battery ECU 100 included in the battery pack 1 constitute battery-side devices that monitor the battery state, including the amount of lithium deposition in the lithium-ion battery.

[0117] The battery module BM is connected to the vehicle's power control unit PCU and motor generator MG via a switch SW2 such as a system main relay. For example, when the vehicle's start switch is turned on, the switch SW2 is turned on, and the battery module BM is electrically connected to the motor generator MG via the power control unit PCU, enabling charging and discharging.

[0118] The battery monitoring device 20 and the battery ECU 100 are basically configured in the same manner as those described above. The battery ECU 100 is capable of communicating with the charger 120 via communication equipment CE. When the battery ECU 100 is capable of communicating with the charger 120, it notifies the charger 120 of battery information including the battery state, such as the amount of lithium deposition and the remaining capacity SOC. The battery ECU 100 also determines whether the battery is in a chargeable state and notifies the charger 120 of the determination result as one piece of battery information. The battery ECU 100 also sets a CC charging current, which is a target current amount during constant current charging, and a CV charging voltage, which is a target voltage during constant voltage charging, and notifies the charger 120 of these set values. Note that communication between the communication equipment CE and the charger 120 is performed via a CAN and a communication line included in the charging cable CC.

[0119] The charging cable CC electrically connects the battery module BM and the charger 120. The charging cable CC includes a cable, a charging connector (not shown), a control box (not shown), and the like.

[0120] The charger 120 is a device that charges the battery module BM. The charger 120 is configured with equipment that complies with charging standards such as CHAdeMO, CCS, and GB / T. A switch SW1 that turns on and off the electrical connection between the charger 120 and the battery module BM is provided between the charger 120 and the battery module BM. This switch SW1 may be provided on the charger 120 side or on the vehicle side.

[0121] The charger 120 includes an information acquisition unit 121, a charging determination unit 122, a charging control unit 123, and a charging time calculation unit 124. The information acquisition unit 121, the charging determination unit 122, the charging control unit 123, and the charging time calculation unit 124 are configured by, for example, a microcomputer equipped with a processor, a memory, an I / O, etc.

[0122] The information acquisition unit 121 acquires battery information including the battery state such as the amount of lithium deposition and the remaining capacity SOC from the battery monitoring device 20 and the battery ECU 100 when the battery module BM is being charged, etc. The information acquisition unit 121 also acquires the CC charging current and the CV charging voltage from the battery ECU 100.

[0123] Here, the amount of lithium deposition is important information indicating the safety of the battery module BM. Therefore, the information acquisition unit 121 of this embodiment is configured to notify the outside of the battery information including the information indicating the amount of lithium deposition by the notification device ND. The notification device ND is configured with devices such as a display, a speaker, a lamp, etc.

[0124] The charging determination unit 122 determines whether or not the battery module BM can be charged based on the battery information acquired by the information acquisition unit 121. For example, the charging determination unit 122 determines whether or not the battery module BM can be charged based on the result of a determination made by the battery ECU 100 as to whether or not the battery module BM is in a chargeable state. Note that the charging determination unit 122 may be configured to determine whether or not charging is possible based on the amount of lithium deposition acquired by the information acquisition unit 121, etc.

[0125] The charge control unit 123 charges the battery module BM based on the determination result of the charge determination unit 122. The charge control unit 123 charges the battery module BM when the determination result of the charge determination unit 122 indicates that charging of the battery module BM is possible, and does not charge the battery module BM when the determination result indicates that charging of the battery module BM is not possible.

[0126] The charging control unit 123 of this embodiment is configured to charge the battery module BM using a CCCV charging method, which involves charging at a constant current followed by charging at a constant voltage. Hereinafter, charging at a constant current may be referred to as CC charging, and charging at a constant voltage may be referred to as CV charging.

[0127] The charging time calculation unit 124 estimates the required charging time based on the battery status acquired by the information acquisition unit 121, and notifies the outside via the notification device ND of information indicating the estimated required charging time. The charging time calculation unit 124 can be configured to estimate the required charging time using, for example, a control map that defines the relationship between the remaining capacity of the battery module BM and the required charging time. When notifying the outside via the notification device ND of the required charging time, the charger 120 preferably notifies the outside by including how much the current rapid charging has shortened the charging time compared to normal charging. Furthermore, the charger 120 preferably notifies the information terminal held by the user of the remaining time until charging is complete.

[0128] The charging system BCS configured as described above is required to have a higher energy density and be capable of faster charging.Recently, attempts have been made to shorten the charging time of the battery module BM by making the charger 120 compatible with 50 kW for CHAdeMO 1.0 specifications, 400 kW for CHAdeMO 2.0 specifications, and 900 kW for CHAdeMO 3.0 specifications.

[0129] Charging time can be shortened by increasing the charging power, but the increased charging current caused by high-power charging accelerates lithium deposition on the battery's negative electrode, which can significantly reduce the battery's lifespan and safety.

[0130] To avoid this, a charging profile can be developed that will prevent deterioration and unsafe conditions, such as by performing a pre-charging with a small current before CC charging, as shown in Figure 15, to detect abnormalities such as deep discharge of the battery.

[0131] However, if preliminary charging is performed for safety reasons, the charging time will be longer, which may cause inconvenience to the user. Furthermore, if the charging time is longer than expected, the user may feel anxious or irritated.

[0132] Taking these into consideration, the charging system BCS of this embodiment is configured so that the charger 120 determines whether or not the battery module BM can be charged based on the battery information acquired from the battery monitoring device 20 and the battery ECU 100.

[0133] The control process on the battery ECU 100 side when charging of the battery module BM starts will be described below with reference to Fig. 16. This control process is performed periodically or irregularly by the battery ECU 100. Note that each control step of the control process shown in Fig. 16 constitutes a function realization unit that realizes various functions executed by the battery ECU 100.

[0134] 16, in step S200, the battery ECU 100 determines whether or not the charger 120 is connected. The battery ECU 100 waits until the charger 120 is connected, and when the charger 120 is connected, the process proceeds to step S210.

[0135] In step S210, the battery ECU 100 executes an initial process. In the initial process, the battery ECU 100 initializes flags and the like, and acquires the monitoring results of the battery monitoring device 20.

[0136] Next, the battery ECU 100 determines whether the battery module BM is in a chargeable state. For example, the battery ECU 100 determines that charging is possible if the amount of lithium deposition is within a predetermined value, and determines that charging is not possible if the amount of lithium deposition exceeds the predetermined value. Note that the battery ECU 100 may also determine that charging is not possible if the battery module BM is in an overcharged state or a deep discharged state.

[0137] If charging to the battery module BM is possible, the battery ECU 100 sets the charge amount to the battery module BM in step S230. The battery ECU 100 calculates the charge amount to the battery module BM based on, for example, the remaining capacity SOC and volumetric capacity ratio SOH of the battery module BM. The battery ECU 100 also sets a CV charging voltage in step S240. The battery ECU 100 sets, for example, a voltage value recommended as the charging voltage for the battery module BM as the CV charging voltage. The battery ECU 100 also sets a CC charging current in step S250. The battery ECU 100 sets, for example, a current value recommended as the charging current for the battery module BM as the CC charging current. The battery ECU 100 then notifies the charger 120 of battery information indicating the battery state, including the amount of lithium deposition, and various settings, including the CV charging voltage and CC charging current, and exits this control process.

[0138] On the other hand, if charging to the battery module BM is not possible, the battery ECU 100 notifies the charger 120 in step S270 that charging to the battery module BM is not possible, and then exits this control process.

[0139] Next, the control process on the charger 120 side when charging the battery module BM will be described with reference to Fig. 17. This control process is performed periodically or irregularly by the charger 120. Note that each control step of the control process shown in Fig. 17 constitutes a function realization unit that realizes various functions executed by the charger 120.

[0140] 17, in step S300, the charger 120 determines whether or not a notification issued by the battery ECU 100 has been received. The charger 120 waits until a notification from the battery ECU 100 is received, and when a notification from the battery ECU 100 is received, the process proceeds to step S310. In step S310, the charger 120 determines whether or not charging of the battery module BM is possible based on the notification from the battery ECU 100. The process of step S310 is performed by the charging determination unit 122 of the charger 120.

[0141] If the notification from the battery ECU 100 indicates that charging is not possible, the charger 120 notifies the outside via the notification device ND in step S320 of information indicating that charging to the battery module BM is not possible and information indicating the amount of lithium deposition, and does not charge the battery module BM.

[0142] On the other hand, if the notification from the battery ECU 100 indicates that charging is possible, the charger 120 starts CC charging in step S330. The charger 120 charges the battery module BM using the CC charging current set by the battery ECU 100 as the target current amount.

[0143] Next, in step S340, the charger 120 determines whether the voltage of the battery module BM has reached a predetermined voltage. This determination process determines whether it is time to switch from CC charging to CV charging. The predetermined voltage is set to, for example, the CV charging voltage.

[0144] If the voltage of the battery module BM has not reached the predetermined voltage, the charger 120 determines in step S350 whether or not a notification of update of the CC charging current setting has been received from the battery ECU 100.

[0145] During CC charging, the battery ECU 100 periodically or irregularly executes the setting update process shown in FIG. 18. Specifically, as shown in FIG. 18, the battery ECU 100 determines in step S500 whether the amount of lithium deposition is greater than a predetermined threshold. This threshold is set to a value that assumes the amount of lithium deposition that occurs when an abnormality occurs in the battery. If the amount of lithium deposition is equal to or less than the predetermined threshold, the battery ECU 100 skips the subsequent steps and exits the setting update process. If the amount of lithium deposition is greater than the predetermined threshold, the battery ECU 100 proceeds to step S510. In step S510, the battery ECU 100 resets the CC charging current to a value smaller than the current value. For example, the battery ECU 100 resets the CC charging current to the current value before the amount of lithium deposition exceeded the predetermined threshold. Then, in step S520, the battery ECU 100 notifies the charger 120 of the updated CC charging current setting.

[0146] 17 , upon receiving notification from the battery ECU 100 of an update to the CC charging current setting, the charger 120 updates the CC charging current to the current amount notified by the battery ECU 100 in step S360. That is, if the amount of lithium deposition increases beyond a predetermined threshold during CC charging, the charger 120 reduces the amount of constant current. The processing of step S360 is performed by the charging control unit 123 of the charger 120.

[0147] When the voltage of the battery module BM reaches the predetermined voltage, the charger 120 proceeds to step S370 and starts CV charging. The charger 120 charges the battery module BM with the CV charging voltage set by the battery ECU 100 as the target voltage.

[0148] Subsequently, in step S330, the charger 120 determines whether or not the current flowing through the battery module BM is equal to or less than a predetermined value, or whether or not the time that has elapsed since the start of charging the battery module BM is equal to or greater than a predetermined time.

[0149] If the current flowing through the battery module BM is greater than a predetermined value and the elapsed time since the start of charging is within a predetermined time, the charger 120 continues CV charging. If the current flowing through the battery module BM is equal to or less than the predetermined value or the elapsed time since the start of charging exceeds a predetermined time, the charger 120 executes charging termination processing in step S390 and then exits this control processing. In the charging termination processing, the notification device ND notifies the user of, for example, charging completion, charge amount, battery state, etc.

[0150] The charging system BCS described above includes a charger 120 for a battery module BM including a lithium-ion battery. The charger 120 includes an information acquisition unit 121 that acquires battery information from the battery-side device, a charging determination unit 122 that determines whether or not the battery module BM can be charged based on the battery information, and a charging control unit 123 that charges the battery module BM based on the determination result of the charging determination unit 122. In this way, if the charger 120 is configured to determine whether or not the battery module BM can be charged based on the battery information acquired from the battery-side device, the charging time can be shortened compared to a system that determines whether or not the battery module BM can be charged by performing preliminary charging.

[0151] The charging system BCS of this embodiment also has the following features.

[0152] (1) The charge control unit 123 of the charger 120 is configured to charge the battery module BM using a CCCV charging method, which involves charging at a constant current followed by charging at a constant voltage. The charge control unit 123 reduces the amount of constant current when the amount of lithium deposition during CC charging exceeds a predetermined threshold, as shown in Fig. 19 . This reduces the amount of lithium deposition during CC charging, thereby ensuring the safety of the battery module BM and preventing the charging time of the battery module BM from becoming longer.

[0153] (2) When charging by the charger 120 begins, the battery-side device periodically determines whether the amount of lithium deposition has increased beyond a threshold. If the amount of lithium deposition exceeds the threshold, the battery-side device sets the target current amount for constant current charging to a value smaller than the current current amount and notifies the charger 120 of the target current amount. When the charging control unit 123 acquires the target current amount from the battery-side device during CC charging, it adjusts the amount of constant current based on the target current amount. In this way, if the battery-side device periodically monitors the amount of lithium deposition and the charger 120 adjusts the current amount appropriate for constant current charging based on the monitoring results, it becomes possible to maximize the charging rate to prevent lithium deposition from occurring. This allows the user's waiting time for charging to be appropriately shortened.

[0154] (3) The charger 120 estimates the required charging time based on the battery state and notifies the outside with information indicating the estimated required charging time via the notification device ND. This allows the user to know the approximate waiting time, thereby reducing the psychological burden on the user when charging the battery module BM.

[0155] (4) The charger 120 notifies the outside with information indicating the amount of lithium deposition by the notification device ND. In this way, if it is possible to provide the user with information indicating not only the required charging time but also the amount of lithium deposition, the user will be able to understand the safety of lithium-ion batteries, and it will be possible to alleviate the user's anxiety about lithium-ion batteries.

[0156] [Modification of the charging system BCS] The charging system BCS may not be identical to the one described above, and may be partially different from the one described above. In addition, the technical matters described above may be applied to devices and systems other than in-vehicle devices.

[0157] [Battery Evaluation System BRS and Battery Evaluation Method] Lithium ion batteries can experience lithium deposition when charged at low temperatures or at high speeds. If lithium deposition progresses, it can cause an internal short circuit, which can lead to fire and smoke. Therefore, when reusing storage batteries, including lithium ion batteries, it is important to understand their safety by taking into account not only the degree of deterioration but also the state of lithium deposition.

[0158] Taking this into consideration, the battery evaluation system BRS and the battery evaluation method of this embodiment are configured to determine the safety of a storage battery based on the amount of lithium deposition. In addition, the battery evaluation system BRS functions as a support system that supports the reuse and rebuilding of battery modules BM. The battery evaluation system BRS and the battery evaluation method will be described below with reference to FIGS. 20 to 22.

[0159] As shown in FIG. 20, the battery evaluation system BRS includes a battery monitoring device 20 as a battery monitoring unit that monitors the battery state of the battery module BM, and an evaluation device 130 that evaluates the battery module BM.

[0160] The battery monitoring device 20 is basically configured in the same manner as described above. The battery monitoring device 20 is configured to be able to calculate the amount of lithium deposition in the lithium ion batteries included in the battery module BM as an index indicating the battery state. The battery monitoring device 20 is capable of outputting battery state information, etc., including the monitoring results of the battery state, including the amount of lithium deposition, to the outside, using the wireless communication unit 52 of the monitoring module 50. In addition to the amount of lithium deposition, this battery state information also includes battery configuration information indicating the use of the battery module BM, the usage history of the battery module BM, etc. Note that the battery monitoring device 20 may be configured to be able to output the battery state information, etc., to the outside using a communication device other than the wireless communication unit 52 of the monitoring module 50.

[0161] The evaluation device 130 is configured to be able to communicate with the battery monitoring device 20, a data center storing market buying and selling information for reused batteries, and information terminals UA, UB, UC, etc. owned by users, distributors, secondary users, etc. via a wired or wireless communication network. The evaluation device 130 acquires battery status information from the battery monitoring device 20 and evaluates the battery module BM based on the battery status information. The evaluation device 130 of this embodiment includes a safety determination unit 131, a value calculation unit 132, a use proposal unit 133, a reuse determination unit 134, and an information output unit 135.

[0162] The safety determination unit 131 determines the safety of the battery module BM based on the amount of lithium deposition in the lithium ion batteries included in the battery module BM. The safety determination unit 131 determines that the lower the amount of lithium deposition, the higher the safety, and the higher the amount of lithium deposition, the lower the safety. If the battery module BM includes even one unsafe lithium battery, the safety of the battery module BM will be compromised. For this reason, the safety determination unit 131 is able to rank the safety of each of the multiple lithium ion batteries included in the battery module BM based on the amount of lithium deposition.

[0163] The value calculation unit 132 calculates the value of the battery module BM taking into account the judgment result of the safety of the battery module BM. For example, the value calculation unit 132 calculates the value by assuming that a battery module BM with high safety is more expensive than a battery module BM with low safety.

[0164] 21 , for example, the value calculation unit 132 acquires the degradation state based on the volumetric capacity ratio SOH, safety based on the amount of lithium deposition, battery configuration information including application, and usage history from the battery monitoring device 20, and also acquires market buying and selling information for reused batteries from the data center. The value calculation unit 132 then calculates the purchase price of the battery module BM based on the degradation state, safety, battery configuration information, usage history, and market buying and selling information. The value calculation unit 132 refers to a map that associates the degradation state, safety, battery configuration information, usage history, market buying and selling information, and the purchase price of the battery module BM, and calculates the purchase price of the battery module BM based on the information acquired from the battery monitoring device 20 and the data center. Note that the value calculation unit 132 may also be configured to calculate the selling price of the battery module BM.

[0165] The usage suggestion unit 133 proposes transitional usage of the battery module BM when it is reused, taking into account the judgment result of the safety of the battery module BM. The usage suggestion unit 133 proposes recommended usage of the battery module BM when it is reused, based on the degradation state, safety, battery form information, and usage history, for example, as shown in Fig. 21. The usage suggestion unit 133 refers to a map that associates the degradation state, safety, battery form information, usage history, and usage when it is reused, and finds the recommended usage of the battery module BM when it is reused, based on the information acquired from the battery monitoring device 20, for example.

[0166] The reuse determination unit 134 determines whether the lithium ion batteries can be reused, taking into account the safety of each of the lithium ion batteries that make up the battery module BM. For example, the reuse determination unit 134 determines that the lithium ion batteries can be reused if the amount of lithium deposition is equal to or less than a predetermined value, and determines that the lithium ion batteries cannot be reused if the amount of lithium deposition exceeds the predetermined value.

[0167] When reusable lithium-ion batteries are rearranged to rebuild different batteries, the information output unit 135 outputs, as rebuild information, a combination of lithium-ion batteries that is suitable for the intended use of the different batteries, taking into consideration the safety of the lithium-ion batteries, as shown in FIG. 22 .

[0168] Here, the optimal combination of lithium-ion batteries may vary depending on how the rebuilt battery will be used. Therefore, it is desirable that the information output unit 135 outputs a combination that corresponds to how the rebuilt battery will be used to the rebuild system RS that manufactures the rebuilt battery. For example, if the rebuilt battery will be used for a long period of time, such as a stationary type, the information output unit 135 outputs a combination that will ensure a long life and high safety as rebuild information. Furthermore, for example, if the rebuilt battery will be used for a short period of time, the information output unit 135 outputs a combination that prioritizes factors other than life as rebuild information.

[0169] The battery evaluation system BRS and battery evaluation method described above monitor the battery state of the battery module BM and evaluate the battery module BM based on battery state information including the results of the battery state monitoring. The battery monitoring device 20 calculates the amount of lithium deposition in the lithium ion battery as an index indicating the battery state. The evaluation device 130 determines the safety of the battery module BM based on the amount of lithium deposition. This determines an index related to the safety of the battery module BM, such as the lithium deposition state, making it possible to appropriately evaluate the battery module BM, including whether it meets safety requirements.

[0170] The battery evaluation system BRS and the battery evaluation method of this embodiment also have the following features.

[0171] (1) The evaluation device 130 includes a value calculation unit 132 that calculates the value of the battery module BM taking into account the results of the safety assessment of the battery module BM. This makes it possible to provide the user with information on the appropriate value of the battery module BM.

[0172] (2) The evaluation device 130 includes a use suggestion unit 133 that suggests uses for the battery module BM when it is reused, taking into account the results of the safety assessment of the battery module BM. This makes it possible to provide the user with information on appropriate uses for the battery module BM.

[0173] (3) The evaluation device 130 ranks the safety of each of the lithium ion batteries included in the battery module BM based on the amount of lithium deposition. This makes it possible to provide the user with information on the appropriate state of the lithium ion batteries that make up the battery module BM.

[0174] (4) The evaluation device 130 includes a reuse determination unit 134 that determines whether or not the lithium ion batteries can be reused, taking into account the safety of each of the lithium ion batteries. This makes it easier to reuse the safe lithium ion batteries in the battery module BM, even if the entire battery module BM cannot be reused.

[0175] (5) When reusable lithium-ion batteries are rearranged to rebuild a battery other than the battery module BM, the evaluation device 130 takes into account the safety of the lithium-ion batteries and outputs a combination of lithium-ion batteries suitable for the intended use of the other battery as rebuild information. This makes it easier to reuse another storage battery by using the highly safe lithium-ion batteries in the battery module BM, even if the entire battery module BM cannot be reused.

[0176] (6) In addition to the amount of lithium deposition, the battery state information includes at least one of the use, usage history, and degradation state of the lithium ion battery. In this way, if the battery module BM is configured to be evaluated using various information, it becomes possible to evaluate the battery module BM from multiple perspectives.

[0177] [Modifications of the battery evaluation system BRS and the battery evaluation method] The battery evaluation system BRS and the battery evaluation method may not be the same as those described above, and may be partially different from those described above. Furthermore, the technical matters described above can be applied to devices and systems other than in-vehicle devices.

[0178] (Second embodiment) Next, a second embodiment will be described with reference to Figures 23 to 25. In this embodiment, an example will be described in which the cause of an abnormality in a battery module BM is identified based on the usage history and manufacturing history of the battery module BM.

[0179] First, the manufacturing process up to mounting the battery pack 1 on a vehicle will be described with reference to Fig. 23. As shown in Fig. 23, the battery pack 1 is mounted on a vehicle through a process of manufacturing the battery cells C → a process of manufacturing the battery module BM → a process of manufacturing the battery pack 1 → a process of assembling the battery pack to the vehicle.

[0180] The manufacturing process for the battery cell C involves forming the electrode body, assembling the cell, injecting the electrolyte, initial charge / discharge, and a performance test, in this order. This performance test includes, for example, visual inspection of the battery cell C itself, inspection for foreign matter, and battery characteristic inspection using inspection equipment.

[0181] In lithium-ion batteries, lithium ions can be reduced and precipitated at the negative electrode. In particular, when charging with a large current or at a low temperature, or when metallic foreign matter is mixed into the battery and current density is concentrated, lithium ions released from the positive electrode active material cannot be fully absorbed into the negative electrode active material and are prone to being precipitated on the negative electrode surface. When lithium is precipitated on the negative electrode, the amount of lithium ions contributing to the battery reaction decreases, which can lead to a decrease in capacity or the occurrence of an internal short circuit.

[0182] For this reason, in the manufacturing process of battery cell C, the current and temperature conditions under which lithium deposition does not occur are calculated and mapped, and manufacturing techniques and inspections are carried out to prevent the inclusion of metallic foreign matter in battery cell C. In the manufacturing process of battery cell C, for example, the presence or absence of lithium deposition is inspected by shining light on the electrode surface of battery cell C, and the ease of lithium deposition is inspected by measuring the resistance distribution on the surface of the negative electrode active material.

[0183] In the subsequent manufacturing process of the battery module BM, module assembly is performed in which the battery cells C are assembled together, and sensor assembly is performed in which the sensor unit 30 and the like are assembled to the assembly of the battery cells C. In this manufacturing process of the battery module BM, the battery monitoring device 20 is attached to the battery module BM. As a result, at the manufacturing stage of the battery module BM, the amount of lithium deposition and the like can be monitored by the battery monitoring device 20.

[0184] In the subsequent manufacturing process of the battery pack 1, pack assembly is carried out in which the assembled battery modules BM are housed in a sealed container 11. In this process, inspections such as checking continuity are carried out as appropriate.

[0185] In the subsequent vehicle assembly process, the battery pack 1 is assembled into the vehicle and a vehicle inspection is carried out. The vehicle inspection checks the continuity with the on-board devices, etc. After that, the vehicle equipped with the battery pack 1 is shipped from the factory to the user.

[0186] Incidentally, it is possible to disassemble the battery cell C and inspect the amount of lithium deposition, but this inspection method is difficult to implement on battery cells C that are actually in use or in the manufacturing process, let alone in the development stage.

[0187] In response to this, the battery monitoring device 20, as shown in FIG. 24, includes a deposition amount detection unit 37 that calculates the amount of lithium deposition using the output of a sensor installed in the battery module BM, and a memory unit 51 that stores the change in the amount of lithium deposition over time as one of the battery usage histories.

[0188] For example, when the user drives the vehicle, the battery monitoring device 20 stores the amount of lithium deposition and the like as part of the usage history in the storage unit 51, which is a storage medium. The battery monitoring device 20 also stores the amount of lithium deposition and the like in the manufacturing process of the battery module BM, the manufacturing process of the battery pack 1, and the vehicle assembly process as part of the manufacturing history in the storage unit 51 or an external storage device.

[0189] The battery monitoring device 20 also includes an abnormality identification unit 544 that, when an abnormality occurs in the lithium-ion battery, identifies the cause of the abnormality based on the usage history stored in the memory unit 51 and the manufacturing history stored in the memory unit 51 and an external storage device. The abnormality identification unit 544 uses the manufacturing history as reference data and compares the manufacturing history with the usage history to identify the time when the abnormality occurred in the lithium-ion battery, and identifies the cause of the abnormality in the lithium-ion battery by verifying the battery state before and after the time of the abnormality. For example, as shown in FIG. 25, the abnormality identification unit 544 identifies the time when the amount of lithium deposition increased as the time when the abnormality occurred in the lithium-ion battery.

[0190] The other points are the same as those in the first embodiment. The battery monitoring device 20 of this embodiment can obtain the same effects as those in the first embodiment that are achieved by a configuration common to or equivalent to that of the first embodiment.

[0191] The battery monitoring device 20 of this embodiment also has the following features.

[0192] (1) The battery monitoring device 20 includes a memory unit 51 that stores the change in the amount of lithium deposition over time as part of the usage history or manufacturing history of the lithium-ion battery. This configuration allows the amount of lithium deposition to be detected nondestructively and appropriately in a short time, enabling inspection of the state of lithium deposition. In particular, since a sensor for detecting lithium deposition is installed in the battery module BM, it is possible to detect the state of lithium deposition regardless of time or location. Furthermore, by storing the change in the amount of lithium deposition over time in the memory unit 51 as part of the usage history or manufacturing history of the lithium-ion battery, it is possible to clearly determine when lithium deposition occurred. This has the advantage of making it clear who is responsible for lithium deposition.

[0193] (2) The battery monitoring device 20 also includes an anomaly identification unit 544 that, when an anomaly occurs in a lithium-ion battery, identifies the cause of the anomaly based on the usage history and the manufacturing history of the lithium-ion battery. In this way, if the cause of the anomaly in the lithium-ion battery is identified based on historical information, including not only the usage history but also the manufacturing history, the cause of the anomaly can be traced back not only to the usage stage but also to the manufacturing stage. This significantly contributes to clarifying where responsibility lies.

[0194] (Modification of the second embodiment) The battery monitoring device 20 of the second embodiment is not the same as that described above, and may be partially different from that described above. Furthermore, the technical matters described in the second embodiment can be applied to devices and systems other than in-vehicle devices.

[0195] (Third embodiment) Next, a third embodiment will be described with reference to Fig. 26 to Fig. 33. In this embodiment, an example in which the battery management unit BMU of the present disclosure is applied to a stationary large-capacity power storage system BSS will be described.

[0196] As shown in FIGS. 26, 27, and 28, the large-capacity power storage system BSS includes a storage container SC, a plurality of battery modules BM, a blower CM, a heater HM, a battery management unit BMU, and the like.

[0197] Each of the battery modules BM is a storage battery including a lithium-ion battery. Each of the battery modules BM is provided with a sensor unit 30. The sensor unit 30 has the same configuration as that described in the first embodiment.

[0198] The storage container SC is a container that stores a plurality of battery modules BM. The storage container SC is appropriately provided with openings to ensure ventilation. The storage container SC is provided with a blower CM and a heater HM.

[0199] The air blower CM is a cooling element for the battery module BM, and generates an airflow inside the storage container SC. The air blower CM may be configured as a device that draws air into the storage container SC, or as a device that pushes air into the storage container SC. The operation of the air blower CM is controlled in response to a control signal from the battery control device 140, which will be described later.

[0200] The heater device HM is a heating element for the battery module BM and includes a heating element that generates heat when energized. The heater device HM may be configured to directly heat the battery module BM or may be configured to indirectly heat the battery module BM. The operation of the air blower CM is controlled in response to a control signal from the battery control device 140, which will be described later.

[0201] The battery management unit BMU manages multiple battery modules BM. The battery management unit BMU includes a sensor unit 30 that monitors the battery state including the amount of lithium deposition in the lithium ion battery, and a battery control device 140 that controls charging of the multiple battery modules BM.

[0202] The battery control device 140 controls the charging of the multiple battery modules BM based on the battery status monitored by the sensor unit 30. The battery control device 140 charges the multiple battery modules BM using, for example, power obtained by solar power generation or power during times when electricity rates are low.

[0203] Furthermore, a notification device ND is connected to the battery control device 140. The battery control device 140 notifies the battery state and the like monitored by the sensor unit 30 to the outside via the notification device ND.

[0204] In lithium-ion batteries, the electrode potential during charging drops to near the redox potential of lithium, making lithium prone to precipitation in situations such as low-temperature charging, large-capacity charging, and overcharging. Lithium precipitation reduces the available lithium ions inside the battery, causing a rapid decrease in battery capacity. Furthermore, continued lithium precipitation can cause an internal short circuit and, in the worst case, lead to thermal runaway of the battery.

[0205] Furthermore, once a battery fails, it may become impossible to store the energy generated until batteries become widespread, which can cause significant losses for users and businesses. Therefore, to continue using batteries safely and securely, it is necessary to properly manage the temperature of lithium-ion batteries while charging and discharging them, as well as to detect signs of battery failure such as internal short circuits early and minimize downtime.

[0206] In response to this, for example, as shown in FIG. 29, when the temperature of a lithium ion battery falls below a predetermined low temperature threshold, it is conceivable to use the electricity stored in the battery as a power source to raise the temperature of the battery using a heating element such as a heater device HM.

[0207] However, the above-mentioned control method focuses only on battery temperature, and depending on the battery's charge / discharge rate, it may not be necessary to heat the battery. Furthermore, focusing only on battery temperature can lead to excessive battery temperature control, potentially resulting in excessive use of the power stored in the battery. Furthermore, in large-scale energy storage facilities such as large-capacity energy storage systems (BSSs), the battery temperature distribution becomes complex, making it difficult to accurately grasp the battery temperature. Furthermore, it is difficult to detect battery failures such as internal short circuits early using only lithium-ion battery temperature information. This can lead to significant downtime as the system breaks down before operators have time to allocate adequate maintenance resources. The charge / discharge rate refers to the speed of charging and discharging.

[0208] Taking these factors into consideration, the battery control device 140 heats the lithium-ion battery in accordance with the amount of lithium deposition during charge control. Note that lithium deposition can occur at times other than during charge control. For this reason, it is desirable that the battery control device 140 heats the lithium-ion battery in accordance with the amount of lithium deposition, not just during charge control.

[0209] 30, when the amount of lithium deposition exceeds a first deposition threshold value Hi and increases, the battery control device 140 starts energizing the heater device HM to heat the battery module BM. The amount of lithium deposition decreases as the battery module BM is heated. Then, when the amount of lithium deposition falls below a second deposition threshold value Lo that is smaller than the first deposition threshold value Hi, the battery control device 140 stops energizing the heater device HM to stop heating the battery module BM.

[0210] As mentioned above, lithium deposition occurs not only during low-temperature charging but also during high-capacity charging, overcharging, etc. In such situations, the battery temperature of the battery module BM may become relatively high.

[0211] For this reason, the battery control device 140 may be configured to heat the lithium ion batteries in accordance with the amount of lithium deposition and the temperature of the battery module BM. For example, as shown in Fig. 31, the battery control device 140 may be configured to energize the heater device HM to heat the battery module BM when the amount of lithium deposition increases beyond a first deposition threshold Hi and the battery temperature of the battery module BM becomes equal to or lower than a predetermined low temperature threshold.

[0212] In addition, when the battery temperature of the battery module BM exceeds the low temperature threshold and the amount of lithium deposition exceeds the first deposition threshold Hi, the battery control device 140 restricts the charging and discharging of the battery module BM and notifies the outside of the battery abnormality using the alarm device ND.

[0213] Here, in order to reduce downtime, it is desirable to replace the battery during the period from when the battery volume ratio SOH decreases to a certain extent due to deterioration until the amount of lithium deposition reaches a level that causes an internal short circuit in the battery, as shown in Figure 32, for example.

[0214] Taking this into consideration, the battery control device 140 of this embodiment estimates the desirable battery replacement interval from the change in the volumetric capacity SOH and the change in the amount of lithium deposition output by the sensor unit 30, and notifies the relevant battery replacement interval as a recommended interval to the outside using the notification device ND. This allows businesses and other entities to know the recommended battery replacement interval, making it possible to reduce downtime due to system failures, including maintenance and battery failure.

[0215] The other points are the same as those in the first embodiment. The battery management unit BMU of this embodiment can obtain the same effects as those in the first embodiment that are achieved by a configuration common to or equivalent to that of the first embodiment.

[0216] Moreover, the battery management unit BMU of this embodiment has the following features.

[0217] (1) When the amount of lithium deposition exceeds a predetermined threshold, the battery management unit BMU heats the battery module BM using the heater device HM, which heats the battery module BM. This allows the lithium-ion battery to be heated at the timing when the amount of lithium deposition increases, thereby appropriately suppressing the increase in the amount of lithium deposition, allowing the lithium-ion battery to be used safely and efficiently. The battery management unit of this invention is particularly suitable for large-scale power storage facilities where temperature distribution is likely to be wide.

[0218] (2) The sensor unit 30 includes a temperature sensor 31 that detects the battery temperature of the lithium-ion battery. The battery control device 140 may be configured to heat the battery module BM using the heater device HM when the amount of lithium deposition increases beyond a predetermined threshold and the battery temperature falls below a predetermined low temperature threshold. This also allows the lithium-ion battery to be used safely and efficiently.

[0219] (Modification of the third embodiment) In the third embodiment, the battery management unit BMU of the large-capacity power storage system BSS has been described in detail, but the battery management unit BMU is not the same as that described above, and may be partially different from that described above.

[0220] Furthermore, the technical matters described in the third embodiment can be applied to devices and systems other than the large-capacity power storage system BSS. The battery management unit BMU can be applied to, for example, power supply management for a mobile body such as a vehicle.

[0221] In the third embodiment, the heating element is configured as the heater device HM, but this is not limiting, and the heating element may be configured as a load device located around the battery. Also, the heating element may be heated by power supplied from a source other than the battery module BM.

[0222] Here, the amount of lithium deposition tends to increase when the battery temperature is low and the charge rate is high, and decrease when the battery temperature is high and the charge rate is low. Thus, there is a certain correlation between the amount of lithium deposition, the charge rate, and the battery temperature. Therefore, the deposition amount detection unit 37 may calculate the amount of lithium deposition by referring to a control map that defines the correlation between the amount of lithium deposition, the charge rate, and the battery temperature, as shown in FIG. 33 . This also applies to other embodiments.

[0223] (Fourth embodiment) Next, a fourth embodiment will be described with reference to Figures 34 and 35. In this embodiment, a battery transport device BSC that stores batteries in a storage container SC and transports them will be described.

[0224] Lithium-ion batteries contain toxic and flammable chemicals, so they must be transported safely. For example, international regulations stipulate packaging standards for air transport based on the lithium content. Batteries used in electric vehicles, such as those with high lithium content, are legally difficult to transport by air, so they are generally transported by sea. Compared to air transport, sea transport takes longer. For example, long transport times can be long, especially in summer, when temperatures are high and humidity is required, and long transport times can be long, especially in winter, when temperatures are low. Under these stressful conditions, if a lithium-ion battery enters an unsafe state, it can become difficult to control, potentially causing damage to other cargo or passengers. Therefore, it is important to monitor the safety of lithium-ion batteries.

[0225] In response to this, it is conceivable to transport lithium-ion batteries using a transport container made of non-flammable materials and equipped with a cooling mechanism, and if an unsafe event in the battery is detected using the gas sensor 35, the lithium-ion battery can be inactivated by the cooling mechanism.

[0226] However, the chemical reaction that leads to an unsafe state in a lithium-ion battery is a chain reaction of exothermic reactions. When using a gas sensor 35 to detect an unsafe event in a battery as in the above-mentioned method, the chain reaction has already begun when gas is released from the lithium-ion battery. Because the chain reaction progresses rapidly, it is difficult to inactivate the lithium-ion battery at this point. Furthermore, the released gas is harmful, and may cause damage to cargo and passengers.

[0227] Taking these factors into consideration, the battery transport device BSC of this embodiment is configured to monitor factors that lead to abnormal heat generation, where the battery temperature continues to rise unintentionally, and to detect abnormal conditions that occur in the battery at the early stage of the abnormal heat generation phenomenon based on the monitoring results.

[0228] As shown in FIG. 34, the battery transport device BSC includes a storage container SC that stores a plurality of battery modules BM, a sensor unit 30A that detects the battery states of the plurality of battery modules BM, and an abnormality detection unit 150.

[0229] 35, the sensor unit 30A includes a humidity sensor HS and an acceleration sensor GS in addition to the temperature sensor 31, gas sensor 35, and deposition amount detection unit 37 described in the first embodiment. The humidity sensor HS is installed inside the storage container SC to detect the humidity inside the storage container SC. The acceleration sensor GS is installed inside the storage container SC to detect vibrations and impacts applied to the storage container SC. Note that the sensor unit 30A may include other sensors.

[0230] The sensor unit 30A of this embodiment includes a wireless communication device (not shown) for wireless communication with the anomaly detection unit 150. Note that the sensor unit 30A may also include a communication device for wired communication with the anomaly detection unit 150.

[0231] The abnormality detection unit 150 prevents the occurrence of abnormal heat generation phenomena based on the results of monitoring factors that lead to the abnormal heat generation phenomena, detects abnormal conditions that occur in the battery at the early stage of the abnormal heat generation phenomena, and implements measures against the abnormal heat generation phenomena based on the results of the detection of the abnormal conditions. The abnormality detection unit 150 has the same configuration as the monitoring module 50 described in the first embodiment. That is, the abnormality detection unit 150 includes a memory unit 51, a wireless communication unit 52, an internal resistance detection unit 53, a monitoring IC 54, etc.

[0232] The abnormality detection unit 150 executes the control process shown in Fig. 12 described in the first embodiment in order to prevent and detect abnormal heat generation phenomena at an early stage. Furthermore, the abnormality detection unit 150 executes the external notification process, battery protection process, etc. described in the first embodiment as measures against abnormal heat generation phenomena.

[0233] In the external notification process, a signal indicating the occurrence of an abnormal heat generation phenomenon is output to the notification device ND, and the occurrence of the abnormal heat generation phenomenon is notified to the outside via the notification device ND. In this external notification process, it is desirable to notify to the outside, for example, at least one of the sensor outputs of the temperature sensor 31, humidity sensor HS, and acceleration sensor GS, and location information of the battery module BM in which the abnormal heat generation phenomenon occurred. The reason for this is that it becomes easier to clarify who is responsible for the occurrence of the abnormal heat generation phenomenon. Note that the location information of the battery module BM can be information determined based on, for example, the radio wave intensity of the signal emitted by the sensor unit 30A.

[0234] Other aspects are the same as those of the first embodiment. The battery transport device BSC of this embodiment can obtain the same effects as those of the first embodiment that are achieved by a configuration common to or equivalent to that of the first embodiment.

[0235] The battery transport device BSC of this embodiment also has the following features.

[0236] (1) The battery transport device BSC includes a storage container SC, a factor monitoring unit that monitors factors that lead to abnormal heat generation, which is a phenomenon in which the battery temperature continues to rise unintentionally, and an abnormality detection unit 150 that detects abnormalities in the battery. The abnormality detection unit 150 prevents the occurrence of abnormal heat generation based on the monitoring results of the factor monitoring unit, detects abnormal conditions that occur in the battery in the early stages of the abnormal heat generation, and implements countermeasures against the abnormal heat generation based on the detection results of the abnormal condition. This makes it possible to implement effective heat countermeasures by preventing the occurrence of abnormal heat generation when transporting batteries, and by implementing countermeasures from the early stages of the abnormal heat generation, even if the abnormal heat generation does occur.

[0237] (Modification of the fourth embodiment) In the fourth embodiment, the battery transport equipment BSC has been described in detail, but the battery transport equipment BSC may not be identical to the one described above, and may be partially different from the one described above. Furthermore, the technical matters described in the fourth embodiment can be applied to equipment and systems other than the battery transport equipment BSC.

[0238] (Other embodiments) Representative embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments and can be modified in various ways, for example, as follows.

[0239] The charging system BCS and charger 120 described above must determine whether or not the storage battery can be charged based on battery information and control charging and discharging based on the results of this determination, but do not necessarily require measures to deal with abnormal battery heat generation, etc. Furthermore, the battery information only needs to include information on at least the amount of lithium deposition, and does not necessarily need to include the volume ratio SOH, etc.

[0240] The charging system BCS and charger 120 described above are configured to charge the storage battery by the CCCV charging method, but may be configured to charge the storage battery by other charging methods.

[0241] The charging system BCS and charger 120 described above are configured to charge the storage battery by the CCCV charging method, but may be configured to charge the storage battery by other charging methods.

[0242] In the above embodiment, a method for updating the target current amount during charging has been described in detail, but the method for updating the target current amount may be different from the above. For example, the charger 120 may be configured to maintain the target current amount constant when lithium deposition is detected. Furthermore, the charger 120 may be configured to change the target current amount stepwise or continuously depending on the amount of lithium deposition.

[0243] The charger 120 is preferably, but not necessarily, configured to estimate the required charging time based on the battery state and notify the outside of the information indicating the estimated required charging time by the notification device ND. Also, the charger 120 is preferably, but not necessarily configured to notify the outside of the information indicating the amount of lithium deposition by the notification device ND.

[0244] The application of the above-described charging system BCS and charger 120 is not limited to vehicle batteries mounted on vehicles. The charging system BCS and charger 120 can also be applied to charging stationary storage batteries and portable storage batteries, for example.

[0245] The battery monitoring device 20 described above includes a flexible printed circuit board (FPC) and an ASIC circuit, but is not limited to these. The flexible printed circuit board (FPC) and the ASIC circuit are not essential components of the battery monitoring device 20.

[0246] As in the above-described embodiment, it is preferable that the battery monitoring device 20 corrects the estimated amount of lithium deposition based on the battery temperature or parasitic resistance value, but this is not essential.

[0247] As in the above-described embodiment, it is desirable that the battery monitoring device 20 compares a predetermined battery state estimated from the amount of lithium deposition with a predetermined battery state estimated from other factors to diagnose the suitability of the deposition amount detection unit 37, but this is not necessarily required.

[0248] In the above-described embodiment, the volumetric capacity SOH is estimated based on the amount of lithium deposition and the thickness of the SEI layer of the battery, but the volumetric capacity SOH may be estimated based on other physical quantities. For example, the battery monitoring device 20 may detect a deterioration state of the battery, including cracks in the positive electrode, and calculate the volumetric capacity SOH based on the deterioration state.

[0249] As in the above-described embodiment, it is desirable that the battery monitoring device 20, together with the battery management device 60, can constitute a battery management system BMS that manages the battery module BM, but this is not necessarily the case. The same applies to the charging system BCS and the battery evaluation system BRS. The battery evaluation system BRS may be configured as one functional unit in the battery management system BMS.

[0250] The object to be monitored by the battery monitoring device 20 is not limited to an on-board battery mounted on a vehicle. The battery monitoring device 20 can also be used as a device for monitoring, for example, a stationary storage battery or a portable storage battery.

[0251] The battery monitoring device 20 basically monitors lithium ion batteries, but is not limited to this. Any battery that may have the same problems as lithium ion batteries can also be monitored. Note that the battery monitored by the battery monitoring device 20 does not have to be a modular battery consisting of multiple battery cells C.

[0252] The battery monitoring device 20 may be configured to be connected to the battery ECU 100 by wire rather than wirelessly. The battery monitoring device 20 is not limited to being completely identical to the one described above, and may be partially different from the one described above.

[0253] In the above-described embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential unless they are specifically stated as essential or are clearly considered essential in principle.

[0254] In the above-described embodiments, when numerical values ​​such as the number, values, amounts, ranges, etc. of components of the embodiments are mentioned, they are not limited to the specific numbers unless they are specifically stated as essential or are clearly limited to a specific number in principle.

[0255] In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., the shapes, positional relationships, etc. are not limited to those unless otherwise specified or when they are fundamentally limited to specific shapes, positional relationships, etc.

[0256] The controller and method of the present disclosure may be implemented on a special-purpose computer by configuring a processor and memory programmed to perform one or more functions embodied in a computer program. The controller and method of the present disclosure may be implemented on a special-purpose computer by configuring a processor with one or more dedicated hardware logic circuits. The controller and method of the present disclosure may be implemented on one or more special-purpose computers configured with a processor and memory programmed to perform one or more functions in combination with a processor configured with one or more hardware logic circuits. The computer program may also be stored on a computer-readable non-transitory tangible storage medium as instructions executed by a computer.

[0257] [Features of the present disclosure] The present disclosure has the following features.

[0258] [Disclosure 1] A battery charging system (BCS), a charger (120) for a storage battery (BM) including a lithium-ion battery; a battery-side device (20, 100) that monitors the battery state including the amount of lithium deposition in the lithium ion battery; The charger includes: an information acquisition unit (121) that acquires battery information including the battery state from the battery-side device; a charging determination unit (122) that determines whether or not the storage battery can be charged based on the battery information; a charge control unit (123) that charges the storage battery based on a determination result of the charge determination unit.

[0259] [Disclosure 2] The charging system according to Disclosure 1, wherein the charging control unit is configured to charge the storage battery by a CCCV charging method in which charging is performed at a constant current followed by charging at a constant voltage, and when the amount of lithium deposition increases beyond a predetermined threshold during charging at the constant current, the charging control unit reduces the amount of the constant current.

[0260] [Disclosure 3] The battery-side device is When the charging control unit starts charging the storage battery, it periodically determines whether the amount of lithium deposition has increased beyond the threshold value; When the amount of lithium deposition increases beyond the threshold, a target current amount during charging at the constant current is set to a value smaller than the current current amount, and the target current amount is notified to the charger; The charging system according to Disclosure 2, wherein the charging control unit, when acquiring the target current amount from the battery-side device during charging with the constant current, adjusts the amount of the constant current based on the target current amount.

[0261] [Disclosure 4] The charging system described in any one of Disclosures 1 to 3, wherein the charger estimates the required charging time for the charging based on the battery status, and notifies the outside of the system of information indicating the estimated required charging time by an alarm device (ND).

[0262] [Disclosure 5] The charging system according to any one of Disclosures 1 to 4, wherein the charger notifies the information indicating the amount of lithium deposition to an outside by a notification device (ND).

[0263] [Disclosure 6] A charger for a storage battery (BM) including a lithium-ion battery, an information acquisition unit (121) that acquires battery information including the battery state from a battery-side device (20, 100) that monitors the battery state including the amount of lithium deposition in the lithium ion battery; a charging determination unit (122) that determines whether or not the storage battery can be charged based on the battery information; a charge control unit (123) that charges the storage battery based on a determination result of the charge determination unit; A charger comprising: [Explanation of symbols]

[0264] 20 Battery monitoring device (battery side equipment) 100 Battery ECU (battery side equipment) 120 charger 121 Information Acquisition Department 122 Charge determination section 123 Charging control unit BCS charging system BM battery module (storage battery)

Claims

1. A charging system (BCS), a charger (120) for a storage battery (BM) including a lithium-ion battery; a battery-side device (20, 100) that monitors the battery state including the amount of lithium deposition in the lithium ion battery; The charger includes: an information acquisition unit (121) that acquires battery information including the battery state from the battery-side device; a charging determination unit (122) that determines whether or not the storage battery can be charged based on the battery information; a charge control unit (123) that charges the storage battery based on a determination result of the charge determination unit, The battery-side device includes a deposition amount detection unit (37) that detects the amount of lithium deposition, The deposition amount detection unit utilizes a correlation between the amount of lithium deposition and the behavior of current and voltage when both ends of the lithium ion battery are short-circuited, and estimates the amount of lithium deposition from the behavior.

2. 2. The charging system according to claim 1, wherein the charging control unit is configured to charge the storage battery by a CCCV charging method in which charging is performed at a constant current and then at a constant voltage, and when the amount of lithium deposition increases beyond a predetermined threshold during charging at the constant current, the charging control unit reduces the amount of the constant current.

3. The battery-side device is When the charging control unit starts charging the storage battery, it periodically determines whether the amount of lithium deposition has increased beyond the threshold value; When the amount of lithium deposition increases beyond the threshold, a target current amount during charging at the constant current is set to a value smaller than the current current amount, and the target current amount is notified to the charger; The charging system according to claim 2 , wherein when the charging control unit acquires the target current amount from the battery-side device during charging with the constant current, the charging control unit adjusts the amount of the constant current based on the target current amount.

4. 4. The charging system according to claim 1, wherein the charger estimates a required charging time for the charging based on the battery state, and notifies an external device of information indicating the estimated required charging time by an alarm device (ND).

5. 4. The charging system according to claim 1, wherein the charger notifies the information indicating the amount of lithium deposition to an outside by a notification device (ND).

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