Battery evaluation system and battery evaluation method

Abstract

To provide a battery evaluation system and a battery evaluation method, each enabling a lithium ion battery to be appropriately evaluated.SOLUTION: A battery evaluation system BRS is provided, evaluating a battery module BM including a lithium ion battery. The battery evaluation system BRS comprises a battery monitoring device 20 that monitors the battery state of the battery module BM, and an evaluation device 130 that acquires battery state information including the battery state monitoring result from the battery monitoring device 20 and evaluates a storage battery on the basis of the battery state information. The battery monitoring device 20 is constituted in such a manner that it can calculate a lithium deposition amount in the lithium ion battery as one index indicating the battery state. The evaluation device 130 determines the safety of the battery module BM on the basis of the lithium deposition amount.SELECTED DRAWING: Figure 20

Description

[Technical field]

[0001] The present disclosure relates to a battery evaluation system and a battery evaluation method for evaluating storage batteries including lithium ion batteries. [Background technology]

[0002] Conventionally, there are known battery reuse support systems that grasp the deterioration state of storage batteries, including lithium ion batteries, and notify users of the reuse purpose, selling price, and selling unit according to the deterioration level (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-38522 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, although Patent Document 1 evaluates storage batteries by focusing on the degradation state of lithium-ion batteries, it does not evaluate safety-related indicators such as the state of lithium precipitation, so there is a risk that batteries that do not meet safety requirements will be given a high rating.

[0005] An object of the present disclosure is to provide a battery evaluation system and a battery evaluation method capable of appropriately evaluating lithium ion batteries. [Means for solving the problem]

[0006] The invention described in claim 1 is A battery evaluation system for evaluating a storage battery (BM) including a lithium ion battery, a battery monitoring unit (20) that monitors the battery state of the storage battery; an evaluation device (130) that acquires battery state information including a monitoring result of the battery state from the battery monitoring unit and evaluates the storage battery based on the battery state information; The battery monitoring unit is configured to be able to calculate the amount of lithium deposition in the lithium ion battery as an index showing the battery state. and a diagnosis unit (541) for comparing a battery state estimated from the amount of lithium deposition with a battery state estimated from factors other than the amount of lithium deposition to diagnose the suitability of a configuration for detecting the amount of lithium deposition, The evaluation device determines the safety of the storage battery based on the amount of lithium deposition.

[0007] The invention described in claim 8 is A battery evaluation method for evaluating a storage battery (BM) including a lithium ion battery, comprising: Monitoring the battery state of the storage battery; obtaining battery state information including a result of monitoring the battery state; and evaluating the storage battery based on the battery state information; By monitoring the battery condition, the amount of lithium deposition in a lithium-ion battery can be calculated as an index of the battery condition. and comparing the battery state estimated from the amount of lithium deposition with the battery state estimated from factors other than the amount of lithium deposition to diagnose the suitability of a configuration for detecting the amount of lithium deposition; When evaluating a storage battery, the safety of the storage battery is determined based on the amount of lithium deposition.

[0008] According to these methods, since indicators related to the safety of the storage battery, such as the state of lithium precipitation, are judged, it becomes possible to appropriately evaluate the battery, including whether or not it satisfies safety requirements.

[0009] The reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description 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. [Diagram 2] FIG. 1 is an explanatory diagram for explaining a lithium ion battery. [Diagram 3] 1 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. [Diagram 5] 4 is an explanatory diagram for explaining a deposition amount detection unit included in the battery monitoring device. FIG. [Figure 6] FIG. 4 is an explanatory diagram for explaining a method for calculating the amount of lithium deposition. [Figure 7] FIG. 11 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 a diagnosis unit. FIG. [Figure 10] FIG. 2 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 the occurrence of an abnormal heat generation phenomenon. [Figure 12] 4 is an explanatory diagram for explaining the flow of a control process executed by a battery monitoring device; FIG. [Figure 13] 1 is a schematic configuration diagram of a battery management system including a battery monitoring device. [Figure 14] 1 is a schematic diagram of a charging system including a battery monitoring device; [Figure 15] FIG. 4 is an explanatory diagram for explaining current and voltage during charging of a battery module in a charging system serving as a comparative example of the first embodiment. [Figure 16] 4 is an explanatory diagram for explaining the flow of a control process executed by the battery monitoring device when charging of the battery module is started; FIG. [Figure 17] FIG. 4 is an explanatory diagram for explaining the flow of a control process executed by a charger. [Figure 18] 4 is an explanatory diagram for explaining the flow of a control process executed by a battery monitoring device while a battery module is being charged; FIG. [Figure 19] FIG. 2 is an explanatory diagram for explaining current and voltage when the battery module is charged in the charging system of the first embodiment. [Figure 20] FIG. 1 is a schematic diagram of a battery evaluation system. [Figure 21] FIG. 1 is a schematic block diagram for explaining value assessment and use proposal of a battery module by a battery evaluation system. [Figure 22] FIG. 4 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 point where the battery pack is mounted on a vehicle. [Figure 24] FIG. 11 is an explanatory diagram for explaining some functions of a battery monitoring device according to a second embodiment. [Diagram 25] FIG. 2 is an explanatory diagram for explaining the timing of lithium precipitation in a lithium ion battery. [Figure 26] FIG. 11 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 an 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. 13 is an explanatory diagram for explaining temperature control of a large-capacity electricity storage system serving as a comparative example of the third embodiment. [Diagram 30] FIG. 11 is an explanatory diagram for explaining temperature control of a large-capacity electricity storage system according to a third embodiment. [Diagram 31] FIG. 13 is an explanatory diagram for explaining a modified example of temperature control. [Diagram 32] FIG. 11 is an explanatory diagram for explaining a suitable time for battery replacement. [Diagram 33] FIG. 4 is an explanatory diagram for explaining the relationship between the charge rate and the temperature and the amount of lithium deposition. [Diagram 34] FIG. 13 is a schematic configuration diagram of a battery transportation device according to a fourth embodiment. [Diagram 35] FIG. 1 is a schematic system configuration diagram of a battery transportation device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, the same reference numerals are used for parts that are the same as or equivalent to those described in the preceding embodiments, and the description thereof may be omitted. In addition, in the embodiments, when only a part of the components is described, the components described in the preceding embodiments can be applied to the other parts of the components. In the following embodiments, each embodiment can be partially combined with each other, even if not specifically stated, as long as it does not cause any trouble in combination.

[0012] (First embodiment) In this embodiment, first, an example in which a battery monitoring device 20 and a battery monitoring method according to 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 Fig. 1. The battery pack 1 includes a sealed container 11 that forms an outer shell, and a plurality of battery modules BM, a battery monitoring device 20, and a battery ECU 100 are housed inside the sealed container 11. 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 an electric device such as an electric motor for vehicle running (not shown) and are a power source for supplying power to the electric device. The battery modules BM are electrically connected in series. The battery modules BM are an assembled battery in which a plurality of battery cells C are electrically connected in series. In the present embodiment, the battery pack 1 including three battery modules BM is illustrated, but the number of battery modules BM is not limited to this and may be any number. The number of battery cells C constituting the battery module BM may also be any number. Some of the battery modules BM may be electrically connected in parallel. Hereinafter, the battery cells C and the battery modules BM may be simply referred to as batteries. The battery module BM in the present embodiment is a storage battery including a lithium-ion battery.

[0015] The battery cell C is a rechargeable secondary battery. The battery cell C is a lithium-ion battery. For example, as shown in FIG. 2, the lithium-ion battery is configured with lithium iron phosphate LFP or nickel-manganese-cobalt NMC as a positive electrode material and graphite as a negative electrode material. In addition, the lithium-ion battery is configured with, for example, a positive electrode collector made of aluminum and a negative electrode collector made of copper. The lithium-ion battery configured in this way has excellent charge and discharge cycle characteristics, but has the characteristic that the electrode potential is very close to the lithium deposition potential, and lithium is easily deposited 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. Since 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, since 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 state 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 constituting the sensor unit 30 are mounted on the flexible substrate FPC. It is not necessary for all of the various sensors constituting the sensor unit 30 to be mounted on the flexible substrate FPC. However, it is preferable that the temperature sensor 31, the strain sensor 34, and the gas sensor 35 are located near the battery cells C, and therefore 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 battery. As shown in Fig. 1, a plurality of temperature sensors 31 are mounted on the flexible substrate FPC. The flexible substrate FPC is mounted with the same number of temperature sensors 31 as the number of battery cells C or a number slightly less than the number of battery cells C so that the battery temperatures of all the lithium-ion batteries constituting the battery module BM can be grasped. 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 sensor 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 the strain of each battery cell C caused by gas generation or the like inside each battery cell C. Note that the strain of 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 capable of detecting 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 the 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 substrate FPC. The calculator 372 is mounted on the monitoring module 50.

[0026] Although not shown, the short circuit 371 has a short circuit switch for shorting both ends of the lithium ion battery, a coil, and a capacitor. A self-resonant circuit is formed by the internal resistance of the lithium ion battery, and the coil and capacitor of the short circuit 371.

[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 at least one of the signal waveforms of the current and voltage flowing through the short circuit 371, and calculates an estimate 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 deterioration 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 about 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 obtain the amount of lithium deposition by 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 amount of lithium deposition as a corrected value obtained by correcting the above estimated value with 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 a 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. The calculator 372 functions as a calibration means for correcting the estimated value of the amount of lithium deposition, in addition to functioning as a means for estimating the amount of lithium deposition.

[0032] Here, the parasitic resistance value is obtained by connecting the deposition amount detection unit 37 to a calibration device CD having a known impedance Z before connecting the deposition amount detection unit 37 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 obtained in this state. Then, the parasitic resistance value is 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 extremely effective in detecting the amount of lithium deposition with high accuracy.

[0034] The short circuit 371 of this embodiment includes a coil, which increases the size of the circuit, and therefore it is necessary to appropriately reduce the size of the circuit in consideration of ease of installation. The reduction in size can be achieved, for example, by improving the saturation magnetic flux density of the coil. Specific means for reducing the size include, for example, using a coil made of a material with high magnetic flux density, and 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 charged. This film is also called the SEI layer. SEI is an abbreviation for Solid Electrolyte Interphase.

[0036] The thickness of the SEI layer is correlated 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 coating 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, the coating detection unit 38 extracts a component that is correlated with the thickness of the SEI layer contained in at least one of the signal waveforms of the current and the voltage flowing through the short circuit 371 when both ends of the battery are short-circuited by 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 it with the battery temperature, as in the detection of the amount of lithium precipitation.

[0037] Here, the amount of lithium precipitation and the thickness of the SEI layer are physical quantities that are more highly correlated with the deterioration of the capacity of the battery than the voltage and current of the battery. In this embodiment, the precipitation amount detection unit 37 and the coating detection unit 38 constitute a "deterioration detection unit" that detects a physical quantity that is more highly correlated with the deterioration of the capacity of the battery than the voltage and current of the battery. In addition, the amount of lithium precipitation is one of the factors that lead to the abnormal heat generation phenomenon in which the temperature of the battery continues to rise unintentionally. For this reason, the precipitation amount detection unit 37 constitutes a "factor monitoring unit" that monitors the factors that lead to the abnormal heat generation phenomenon.

[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, the monitoring module 50 will be described. 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 "anomaly 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 above-mentioned parasitic resistance value, etc. The storage unit 51 is configured of a non-transient tangible storage medium.

[0041] The wireless communication unit 52 is a communication device for enabling 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, etc., 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 to detect abnormalities in the battery. The monitoring IC 54 prevents the occurrence of abnormal heat generation based on the results of monitoring factors that lead to the abnormal heat generation phenomenon, detects abnormal conditions occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the results of the detection of the abnormal condition.

[0044] The monitoring IC 54 includes an ASIC circuit having an algorithm that performs at least a part of the monitoring of factors that lead to the abnormal heat generation phenomenon and the detection of an abnormal state that occurs in the battery at the early stage of the occurrence of the abnormal heat generation phenomenon. Specifically, the monitoring IC 54 is configured to have a diagnosis unit 541, a SOH estimation unit 542, and a monitoring control unit 543 as functional units that execute 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 the 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 volume rate SOH of the battery from the amount of lithium deposition detected by the deposition amount detection unit 37. The diagnosis unit 541 also estimates the volume rate SOH of the battery based on the sensor outputs of the temperature sensor 31, the current sensor 32, and the voltage sensor 33. Note that SOH is an abbreviation for State of Health.

[0047] Next, the diagnosis unit 541 compares the volume rate SOH estimated from the amount of lithium deposition with the volume rate SOH estimated from the temperature, current, and voltage of the battery using a state comparator to diagnose whether the deposition amount detection unit 37 is suitable. For example, the diagnosis unit 541 diagnoses the deposition amount detection unit 37 as suitable if the deviation between the volume rate SOH estimated from the amount of lithium deposition and the volume rate SOH estimated from the temperature, current, and voltage of the battery is within a predetermined range. On the other hand, the diagnosis unit 541 diagnoses the deposition amount detection unit 37 as unsuitable if the deviation between the volume rate SOH estimated from the amount of lithium deposition and the volume rate SOH estimated from the temperature, current, and voltage of the battery exceeds a predetermined range. If the deposition amount detection unit 37 is diagnosed as unsuitable, 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 capacity 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 capacity ratio.

[0048] Here, JP2014-102076A discloses a method for calculating the full charge amount of a battery. In this calculation method, first, the current value of the output current of the battery is integrated over time to calculate the change in the charge / discharge amount between the first time point and the second time point. Then, the OCV at the first time point and the second time point are measured, and the remaining capacity SOC at the first time point and the second time point are calculated using the SOC-OCV curve, and a change amount ΔSOC calculated as the deviation of the remaining capacity SOC at each time point is calculated. Next, the full charge amount of the battery is calculated by dividing the change amount of the charge / discharge amount by the change amount ΔSOC of the remaining capacity SOC. Also, the volume ratio SOH of the battery is obtained by dividing the full charge amount of the battery by the initial value of the full charge amount.

[0049] However, the above-mentioned method of calculating the remaining capacity SOC and the volumetric capacity SOH has a problem 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, when calculating the charge / discharge amount, there is a problem in that the calculation error of the volumetric capacity SOH increases over time due to the offset error of the current sensor 32.

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

[0051] One of the causes of battery deterioration is an increase in the internal resistance of the battery. The internal resistance of the 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 the 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 rate SOH using an estimation model of the volumetric rate SOH based on the amount of lithium precipitation, the thickness of the SEI layer, the temperature, current, and voltage of the battery, as shown in Fig. 10. The estimation model of the volumetric rate SOH is, for example, a control map or function that specifies the relationship between the volumetric rate SOH, the amount of lithium precipitation, the thickness of the SEI layer, the temperature, current, and voltage of the battery. Note that the estimation model may be, for example, a model obtained by deep learning, reinforcement learning, or deep reinforcement learning using a neural network.

[0053] This enables real-time diagnosis of the battery condition, which was difficult to do by estimating the volumetric SOH based on the charge / discharge amount. In addition, by accurately measuring the temperature, the effect 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 monitoring results of factors that lead to the abnormal heat generation phenomena, detects abnormal conditions occurring in the battery at the early stage of the occurrence of the abnormal heat generation phenomena, and implements measures against the abnormal heat generation phenomena based on the detection results 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 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 by a microcomputer equipped with a processor, a memory, an I / O, a wireless communication device 110, etc. The battery ECU 100 is configured to be able to communicate with each of the monitoring modules 50A, 50B, 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 an ECU for thermal management that controls a temperature regulator for the battery, and an ECU for an HMI device mounted on the vehicle. The battery ECU 100 is capable of reporting various battery states to the outside via the HMI device, etc.

[0057] The battery pack 1 thus configured includes a rechargeable battery such as a lithium ion battery. This type of battery may experience an abnormal heat generation phenomenon in which a specific component inside the battery heats up due to some trigger, which in turn causes other components to heat up, causing the temperature of the battery to continue to rise unintentionally. If such an abnormal heat generation phenomenon occurs, the thermal reliability of the battery is significantly reduced, which is undesirable. Therefore, in lithium ion batteries and the like, it is important to detect the presence or absence of an abnormal heat generation phenomenon in the battery to ensure 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 an abnormal heat generation phenomenon, the first symptom of a battery abnormality is a change in the volume of the battery caused by an increase in gas pressure inside the battery cell, which causes the output of the strain sensor 34 to show an increasing trend.

[0060] After that, when the volume change of the battery becomes large, the battery is damaged and gas inside the battery cell starts to leak, which causes the output of the gas sensor 35 to tend to increase. When the battery is damaged, the gas pressure inside the battery decreases, and the output of the strain sensor 34 tends to decrease.

[0061] Although not shown in FIG. 11, as the deterioration of the battery progresses, lithium deposition occurs inside the battery and the thickness of the SEI layer increases, leading to an increase in the internal resistance of the battery.

[0062] When the abnormal heat generation phenomenon occurs, the battery temperature and the pressure inside the battery pack 1 (i.e., the pack internal pressure) rise rapidly, and the battery voltage drops rapidly. Furthermore, the output of the gas sensor 35 shows an increasing tendency. These symptoms become noticeable in the early stage of the occurrence of the abnormal heat generation phenomenon.

[0063] Taking these factors into consideration, the battery monitoring device 20 executes a control process for preventing and early detection of an abnormal heat generation phenomenon. An example of the control process executed by the battery monitoring device 20 will be described below 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 each functional unit of the battery monitoring device 20. Also, each step that realizes this process can be understood as each step that realizes a battery monitoring method.

[0065] As shown in Fig. 12, in step S100, the battery monitoring device 20 reads various signals from the sensor unit 30 etc. 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 stage of the occurrence of an abnormal heat generation phenomenon, the battery temperature, the pack internal pressure, and the 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 at least some of the sensor outputs of the temperature sensor 31, the voltage sensor 33, the gas sensor 35, and the pack internal pressure sensor 36.

[0066] When the occurrence of the abnormal heat generation phenomenon is detected, the battery monitoring device 20 proceeds to step S110 and implements measures against 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 by 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 a temperature control device for the battery is operated via the battery ECU 100 to cool the battery. Such battery cooling makes it possible to delay 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 the charging and discharging of the battery is output, and the operation of the battery is restricted to suppress self-heating of the battery. Such charge and discharge control also makes it possible to delay 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 one of 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] The countermeasure against the abnormal heat generation phenomenon is not limited to the above-mentioned process, and may be realized by a process other than the above-mentioned process. The countermeasure against the abnormal heat generation phenomenon may be, 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 process of step S115 and subsequent steps. Note that the process of step S115 and subsequent steps is a process for preventing the occurrence of an abnormal heat generation phenomenon in advance.

[0072] In step S115, the battery monitoring device 20 determines whether or not 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, in step S120, the battery monitoring device 20 executes a charge suppression process and returns to step S115. In this charge suppression process, the battery charging is suppressed and / or the battery is discharged.

[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. In the output limitation, for example, charging and discharging of the battery is suppressed. In the cooling control, for example, the battery is cooled by a temperature adjustment device for the battery.

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

[0075] If lithium deposition is newly detected, the battery monitoring device 20 performs charging, regeneration control, and heating control in step S140, and returns to step S115. In charging and regeneration control, for example, the charging of the battery is suppressed. In heating control, for example, the battery is heated by a battery temperature regulator. Note that each process performed when lithium deposition is detected constitutes an extension process for extending the life of the battery.

[0076] If no new lithium deposition is detected, the battery monitoring device 20 determines whether or not 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 amount of 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 returns to step S115. In the output control, for example, the discharge of the battery is suppressed. In the temperature control, for example, the battery temperature is adjusted by a temperature control device so that the battery temperature is maintained within an appropriate range. In the notification of the degree of deterioration, the degree of deterioration of the battery is determined from the battery's internal resistance, and the determination result of the degree of deterioration or the time to replace the battery estimated from the determination result is notified to the outside. Note that each process performed when a change in internal resistance is detected constitutes an extension process 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 deformation of the battery is detected, the battery monitoring device 20 implements an output restriction on the battery in step S160, and returns to step S115. In the output control, for example, charging and discharging of the battery is restricted.

[0080] If no deformation of the battery is detected, no sign of abnormal heat generation is observed and the battery is considered to be in a normal state. Therefore, if no deformation of the battery is detected, the battery monitoring device 20 ends the control process shown in FIG.

[0081] However, with the rapid electrification of vehicles, it is expected that a large amount of used batteries will be generated in the near future. Since the production of batteries involves the emission of a large amount of CO2 and the use of rare metals, it is expected that a battery ecosystem adapted to a circular society will be established by selecting reuse, rebuild, or recycling for used batteries according to the remaining capacity SOC and volumetric rate SOH of the battery. In order to establish such a battery ecosystem, it is important to correctly diagnose the value of the battery, such as the remaining capacity SOC and volumetric rate SOH. In addition, it is assumed that after the end of in-vehicle use, the battery will be stored until a secondary use destination is decided, but the battery continues to discharge even when not in use, and it is assumed that deterioration will progress depending on the storage condition. Therefore, as a secondary user, it is necessary to understand the remaining capacity SOC and volumetric rate SOH of the battery at that moment, and the real-time performance of the battery diagnosis is important.

[0082] As described above, the battery monitoring device 20 of this embodiment can obtain the remaining capacity SOC and the volume 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 or not 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 secondary reuse is possible 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 secondary reuse is not possible if the volumetric capacity SOH is less than the predetermined value. Note that the performance determination unit 61 may be configured to determine whether or not 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 an abnormality in the battery based on the volumetric capacity SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20, and sets the remaining value of the battery if there is an abnormality in the battery. For example, the value setting unit 62 estimates a low remaining value of the battery as the volumetric capacity SOH decreases. Note that the value setting unit 62 may be configured to set the remaining value of the battery based on a battery condition other than the volumetric capacity 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, when 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 that fact. Also, for example, when 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] According to the battery monitoring device 20 and the battery monitoring method described above, it is possible to implement effective measures against abnormal heat generation, effective detection of the amount of lithium deposition, and effective estimation of the volume rate SOH.

[0089] [Measures against abnormal heat generation] The battery monitoring device 20 and the battery monitoring method monitor factors that lead to abnormal heat generation phenomena, and prevent the occurrence of abnormal heat generation phenomena based on the monitoring results of the factors. In addition, the battery monitoring device 20 and the battery monitoring method detect an abnormal state occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implement measures against the abnormal heat generation phenomenon based on the detection result of the abnormal state. This makes it possible to implement effective heat countermeasures, such as preventing the occurrence of abnormal heat generation phenomena, and implementing measures from the early stage of the occurrence, 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 states in parallel. In other words, the monitoring module 50 detects abnormal battery states regardless of the results of monitoring factors that lead to abnormal heat generation. This allows the abnormal state to be detected earlier than when the abnormal state is detected after monitoring factors that lead to abnormal heat generation, for example, and therefore allows measures to be taken against the abnormal heat generation to be implemented earlier.

[0092] (2) Measures 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 by at least one of temperature adjustment control and charging / discharging control of the battery. When the measures taken against the abnormal heat generation phenomenon include an external notification process, in addition to measures that the battery monitoring device 20 itself can take, measures by devices external to the battery monitoring device 20 or measures in cooperation with external devices can be easily implemented. Furthermore, when the measures taken against the abnormal heat generation phenomenon include a 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 monitoring result of the factors that lead to the abnormal heat generation phenomenon. In this way, by performing a process to extend the battery life in accordance with the monitoring result of the factors that lead to the abnormal heat generation phenomenon, 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 internal resistance of the battery. Lithium deposition inside a lithium-ion battery and an increase in internal resistance can lead to abnormal heat generation in the battery. Therefore, by monitoring lithium deposition and internal resistance, it becomes easier to prevent abnormal heat generation in the battery.

[0095] (5) The monitoring module 50 identifies an abnormal one of 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 multiple battery cells C. In this way, if the configuration is capable of identifying an abnormal cell 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 phenomenon or to slow the progression of the abnormal heat phenomenon.

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

[0097] (7) The battery monitoring device 20 includes an ASIC circuit having an algorithm that performs at least some of the monitoring of factors that may lead to abnormal heat generation and the detection of abnormal states of the battery. This makes it possible to monitor factors that may lead to abnormal heat generation and detect abnormal states with a simple configuration.

[0098] (8) The monitoring module 50 is configured to determine the degree of battery deterioration based on the results of monitoring factors that lead to abnormal heat generation, and to be able to notify an external device of the deterioration degree determination result or the time to replace the battery estimated from the determination result. In this way, if the degree of battery deterioration is determined from the results of monitoring factors that lead to abnormal heat generation, a dedicated device for determining the degree of battery deterioration 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 board FPC on which a part of the sensor unit 30 is mounted. In this way, by mounting a part of the sensor unit 30 on the flexible board FPC that constitutes the connection member 21, factors that lead to abnormal heat generation in the battery can be monitored in 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 shorted by the short circuit 371. The deposition amount detection unit 37 then corrects the estimate of the amount of lithium deposition with the battery temperature. This reduces the effect of the battery temperature included in 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 lithium deposition 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 lithium deposition, improving the detection accuracy of the amount of lithium deposition, and therefore ensures 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 effects 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 obtained by connecting the short circuit 371 to a calibration device CD having a known impedance Z before connecting the short circuit 371 to the lithium ion battery. This makes it possible to obtain the parasitic resistance value of the deposition amount detection unit 37 with high accuracy. This contributes greatly to improving the detection accuracy of the amount of lithium deposition.

[0104] (3) The battery monitoring device 20 includes a diagnosis 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. Since the diagnosis unit 541 can diagnose the accuracy of the deposition amount detection unit 37, the reliability of the deposition amount detection unit 37 can be ensured.

[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. In addition, 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 is more highly correlated with battery capacity degradation than the battery voltage and current, and estimates the battery volume ratio SOH based on the physical quantity. In this way, if the volume ratio SOH is estimated using a physical quantity that is more highly correlated with battery capacity degradation, there is less need to avoid the influence of errors compared to when the volume ratio SOH is calculated from the battery current and voltage, so the volume ratio SOH can 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 precipitation and the thickness of the SEI layer are physical quantities that directly affect the capacity degradation of the battery. Therefore, by detecting the amount of lithium precipitation and the thickness of the SEI layer and calculating the volumetric rate SOH based on the amount of lithium precipitation and the thickness of the SEI layer, real-time performance 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, even if the volumetric rate SOH is calculated based on not only the amount of lithium precipitation and the thickness of the SEI layer but also the degree of cracking of the positive electrode active material, the detection accuracy of the volumetric rate SOH can be improved. 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 the lithium ion battery are short-circuited, or the sensor output of a strain sensor or an 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 with the battery temperature. This reduces the influence of the battery temperature on the estimated amount of lithium precipitation and the thickness of the SEI layer, thereby improving the detection accuracy of the amount of lithium precipitation and the thickness of the SEI layer.

[0110] (4) The battery management system BMS determines whether or not 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 the battery. This contributes greatly to the construction of a battery ecosystem that is suited to a recycling-oriented society.

[0111] (5) The battery management system BMS determines whether or not 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 putting batteries to secondary use, thereby contributing to the construction 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 range of the volumetric capacity SOH 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, which greatly contributes 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 configure a battery side device that monitors the battery state including the amount of lithium deposition in the lithium ion battery.

[0117] The battery module BM is connected to the power control unit PCU and the motor generator MG of the vehicle via a switch SW2 such as a system main relay. For example, when the start switch of the vehicle 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 and enters a state in which it can be charged and discharged.

[0118] The battery monitoring device 20 and the battery ECU 100 are basically configured in the same manner as described above. The battery ECU 100 is capable of communicating with the charger 120 via the communication device 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. Furthermore, the battery ECU 100 sets a CC charging current, which is a target current amount during charging with a constant current, and a CV charging voltage, which is a target voltage during charging with a constant voltage, and notifies the charger 120 of these set values. The communication between the communication device CE and the charger 120 is performed via a communication line included in the CAN and 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 a device that complies with charging standards such as CHAdeMO, CCS, and GB / T. A switch SW1 that turns on and off an 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, and the like.

[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. For this reason, the information acquisition unit 121 of this embodiment is configured to notify the battery information including the information indicating the amount of lithium deposition to the outside by the notification device ND. The notification device ND is composed of devices such as a display, a speaker, and a lamp.

[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 charging control unit 123 charges the battery module BM based on the determination result of the charging determination unit 122. The charging control unit 123 charges the battery module BM when the determination result of the charging 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 by a CCCV charging method in which charging is performed at a constant current and then at a constant voltage. In the following, 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 necessary charging time required for charging based on the battery state acquired by the information acquisition unit 121, and notifies the outside with information indicating the estimated necessary charging time by the notification device ND. The charging time calculation unit 124 can be configured to estimate the necessary charging time by using, for example, a control map that specifies the relationship between the remaining capacity of the battery module BM and the necessary charging time. When notifying the outside with the notification device ND of the necessary charging time, the charger 120 is preferably configured to notify the outside with information on how much the current quick charging has been shortened compared to normal charging. In addition, the charger 120 is preferably configured to notify the remaining time until charging is completed to an information terminal owned by the user.

[0128] There is a demand for a charging system BCS configured as described above that is capable of charging at a higher energy density and at a higher speed. 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 may significantly reduce the battery's lifespan and safety.

[0130] To avoid this, a charging profile can be devised that prevents deterioration or unsafe conditions 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, when preliminary charging is performed for safety reasons, the charging time is increased accordingly, which may cause inconvenience to the user. Furthermore, the user may feel anxious or irritated if the charging time is longer than expected.

[0132] Taking these factors 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] Hereinafter, the control process on the battery ECU 100 side when charging of the battery module BM starts will be described with reference to Fig. 16. This control process is performed periodically or irregularly by the battery ECU 100. 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 judges whether the battery module BM is in a chargeable state. For example, the battery ECU 100 judges that charging is possible if the amount of lithium deposition is within a predetermined value, and judges that charging is not possible if the amount of lithium deposition exceeds the predetermined value. Note that the battery ECU 100 may also be configured to judge that charging is not possible even if the battery module 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 obtains the charge amount to the battery module BM based on, for example, the remaining capacity SOC and the volume ratio SOH of the battery module BM. Furthermore, the battery ECU 100 sets a CV charging voltage in step S240. The battery ECU 100 sets, for example, a voltage value recommended as the charging voltage of the battery module BM as the CV charging voltage. Furthermore, the battery ECU 100 sets a CC charging current in step S250. The battery ECU 100 sets, for example, a current value recommended as the charging current of the battery module BM as the CC charging current. Then, the battery ECU 100 notifies the charger 120 of various settings including battery information indicating the battery state including the amount of lithium deposition, the CV charging voltage, and the CC charging current, and exits this control process.

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

[0139] Next, the control process on the charger 120 side during charging of the battery module BM will be described with reference to Fig. 17. This control process is performed periodically or irregularly by the charger 120. 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, in step S320, the charger 120 notifies the outside via the notification device ND 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 with 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 or not the voltage of the battery module BM has reached a predetermined voltage. This determination process is to determine whether or not 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] Here, the battery ECU 100 periodically or irregularly executes the setting update process shown in FIG. 18 during CC charging. Specifically, as shown in FIG. 18, the battery ECU 100 determines whether the amount of lithium deposition is greater than a predetermined threshold in step S500. This threshold is set to a value that assumes the amount of lithium deposition that will be deposited when the battery is abnormal. 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 from the setting update process, and 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 be smaller than the current current value. For example, the battery ECU 100 resets the CC charging current to a current value before the amount of lithium deposition exceeds the predetermined threshold. Then, in step S520, the battery ECU 100 notifies the charger 120 of the setting update of the CC charging current.

[0146] 17, when the charger 120 receives a notification from the battery ECU 100 to update the setting of the CC charging current, in step S360, the charger 120 updates the CC charging current to the current amount notified by the battery ECU 100. That is, when the amount of lithium deposition increases beyond a predetermined threshold during CC charging, the charger 120 reduces the amount of constant current. Note that the process 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] Next, in step S330, the charger 120 determines whether or not the current flowing through the battery module BM is equal to or lower than a predetermined value, or whether or not the elapsed time since the start of charging the battery module BM is equal to or longer than a predetermined time.

[0149] If the current flowing through the battery module BM is greater than a predetermined value and the elapsed time from 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 a predetermined value or the elapsed time from the start of charging exceeds a predetermined time, the charger 120 executes a charging end process in step S390 and then exits this control process. In the charging end process, for example, the user is notified of charging completion, the charge amount, the battery state, etc. by the notification device ND.

[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 a 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 case in which the charger 120 determines whether or not the battery module BM can be charged by performing preliminary charging.

[0151] Moreover, the charging system BCS of this embodiment has the following features.

[0152] (1) The charge control unit 123 of the charger 120 is configured to charge the battery module BM by a CCCV charging method in which charging is performed at a constant current followed by charging at a constant voltage. Then, the charge control unit 123 reduces the amount of constant current when the amount of lithium deposition during CC charging increases beyond a predetermined threshold, for example, as shown in Fig. 19. This suppresses the amount of lithium deposition during CC charging, and therefore makes it possible to suppress an increase in the charging time of the battery module BM while ensuring the safety of the battery module BM.

[0153] (2) When charging by the charger 120 is started, the battery-side device periodically determines whether the amount of lithium deposition has increased beyond a threshold. When the amount of lithium deposition has increased beyond the threshold, the battery-side device sets the target current amount for charging at a constant current 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 suitable for charging at a constant current based on the monitoring result, it is possible to control the charging rate to be maximized so that lithium deposition does not occur. This makes it possible to appropriately shorten the waiting time for the user due to charging time.

[0154] (3) The charger 120 estimates the charging time required for charging based on the battery state, and notifies the outside of the information indicating the estimated charging time by 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 of the information indicating the amount of lithium deposition by the notification device ND. In this way, if it is possible to provide the user with not only the information indicating the required charging time but also the information indicating the amount of lithium deposition, the user can understand the safety of the lithium ion battery, and it is possible to reduce the user's anxiety about lithium ion batteries.

[0156] [Modification of the charging system BCS] The charging system BCS 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 may be applied to devices and systems other than in-vehicle devices.

[0157] [Battery evaluation system BRS and battery evaluation method] Lithium ion batteries may experience lithium precipitation when charged at low temperatures or at high speeds. If lithium precipitation progresses, it may cause an internal short circuit, which may lead to fire or smoke. Therefore, when reusing storage batteries, including lithium ion batteries, it is advisable to understand the safety of the batteries by taking into account not only the degree of deterioration but also the state of lithium precipitation.

[0158] Taking this into consideration, the battery evaluation system BRS and the battery evaluation method of the present embodiment are adapted to determine the safety of the storage battery based on the amount of lithium deposition. Also, the battery evaluation system BRS functions as a support system for supporting the reuse and rebuilding of the battery module BM. Hereinafter, the battery evaluation system BRS and the battery evaluation method will be described with reference to Figs. 20 to 22.

[0159] As shown in FIG. 20, the battery evaluation system BRS includes a battery monitoring device 20 serving 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 capable of calculating 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 result 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 includes battery form 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 capable of outputting the battery state information, etc., to the outside by 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 of 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 state information from the battery monitoring device 20, and evaluates the battery module BM based on the battery state 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 precipitation in the lithium ion batteries included in the battery module BM. The safety determination unit 131 determines that the smaller the amount of lithium precipitation, the higher the safety, and determines that the larger the amount of lithium precipitation, the lower the safety. If the battery module BM includes even one unsafe lithium battery, the safety of the battery module BM is compromised. For this reason, the safety determination unit 131 is capable of ranking the safety of each of the multiple lithium ion batteries included in the battery module BM based on the amount of lithium precipitation.

[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 regarding a battery module BM with high safety as being more expensive than a battery module BM with low safety.

[0164] 21, the value calculation unit 132 acquires the degradation state based on the volumetric capacity SOH, the safety based on the amount of lithium deposition, battery form information including applications, and usage history from the battery monitoring device 20, and also acquires market buying and selling information of 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 form 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 form information, usage history, market buying and selling information, and the purchase price of the battery module BM, for example, 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. The value calculation unit 132 may 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 consideration 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 constituting 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 precipitation is equal to or less than a predetermined value, and determines that the lithium ion batteries cannot be reused if the amount of lithium precipitation exceeds the predetermined value.

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

[0168] Here, the optimal combination of lithium ion batteries may differ depending on the usage of the rebuilt battery. For this reason, it is desirable that the information output unit 135 is configured to output a combination according to the usage of the rebuilt battery to the rebuild system RS that manufactures the rebuilt battery. For example, when the usage of the rebuilt battery is for a long period of time, such as a stationary type, the information output unit 135 outputs a combination that provides a long life and high safety as rebuild information. Also, for example, when the rebuilt battery is for a short period of time, the information output unit 135 outputs a combination that prioritizes factors other than the life as rebuild information.

[0169] The battery evaluation system BRS and the 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 monitoring result of the battery state. The battery monitoring device 20 calculates the amount of lithium precipitation in the lithium ion battery as an index indicating the battery state. The evaluation device 130 judges the safety of the battery module BM based on the amount of lithium precipitation. In this way, since an index related to the safety of the battery module BM, such as the lithium precipitation state, is judged, it becomes possible to appropriately perform evaluation including whether or not the safety requirements are met.

[0170] Moreover, the battery evaluation system BRS and the battery evaluation method of the present embodiment 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 judgment result of the safety 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 of 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 of 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 proper state of the lithium ion batteries constituting 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 reusing reusable lithium-ion batteries 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 application of the other battery as rebuild information. This makes it easier to build and reuse another storage battery 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. In addition, the above technical matters 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 Fig. 23 to Fig. 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 the vehicle through a manufacturing process of the battery cells C → a manufacturing process of the battery module BM → a manufacturing process of the battery pack 1 → a process of assembling the battery pack to the vehicle.

[0180] The manufacturing process for the battery cell C involves the formation of the electrode body, cell assembly, electrolyte injection, initial charge / discharge, and performance testing in this order. In the performance testing, for example, inspection equipment is used to perform an appearance inspection of the battery cell C alone, a foreign object inspection, and a battery characteristic inspection.

[0181] Here, in lithium ion batteries, lithium ions may be reduced and precipitated at the negative electrode. In particular, when charging with a large current or at a low temperature, or when metal foreign matter is mixed into the battery and the current density is concentrated, the lithium ions released from the positive electrode active material do not enter the negative electrode active material and tend to precipitate on the negative electrode surface. When lithium precipitates on the negative electrode, the amount of lithium ions contributing to the battery reaction decreases, which may lead to a decrease in capacity or an internal short circuit.

[0182] For this reason, in the manufacturing process of battery cell C, the current and temperature conditions under which lithium precipitation does not occur are calculated and mapped, and manufacturing measures and inspections are implemented to prevent metallic foreign matter from being mixed into battery cell C. In the manufacturing process of battery cell C, for example, whether or not lithium has precipitated is inspected by shining light on the electrode surface of battery cell C, and the ease of lithium precipitation 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 next manufacturing process of the battery pack 1, pack assembly is performed in which the assembled battery modules BM are housed in a sealed container 11. In this process, inspections such as checking electrical continuity are appropriately performed.

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

[0186] Incidentally, while it is possible to disassemble the battery cell C and inspect the amount of lithium deposition, such an inspection method is difficult to implement on a battery cell C that is 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, is equipped with 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, etc., 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, etc., 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 in the lithium ion battery based on the usage history stored in the storage unit 51 and the manufacturing history stored in the storage 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 when the abnormality occurred. For example, as shown in FIG. 25, the abnormality identification unit 544 identifies the timing when the amount of lithium deposition increases as the time when the abnormality occurred in the lithium ion battery.

[0190] The rest is the same as in the first embodiment. The battery monitoring device 20 of the present embodiment can obtain the same effects as in the first embodiment, which are achieved by a configuration common to the first embodiment or an equivalent configuration.

[0191] Moreover, the battery monitoring device 20 of this embodiment 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 precipitation over time as one of the usage or manufacturing histories of the lithium ion battery. This allows the amount of lithium precipitation to be detected nondestructively and appropriately in a short time, and allows the lithium precipitation state to be inspected. In particular, since a sensor for detecting lithium precipitation is installed in the battery module BM, it is possible to detect the lithium precipitation state regardless of time or place. Furthermore, by storing the change in the amount of lithium precipitation over time in the memory unit 51 as one of the usage or manufacturing histories of the lithium ion battery, it is possible to clearly grasp when lithium was precipitated. This has the advantage of making it clear who is responsible for lithium precipitation.

[0193] (2) Furthermore, the battery monitoring device 20 includes an abnormality identification unit 544 that, when an abnormality occurs in the lithium-ion battery, identifies the cause of the abnormality in the lithium-ion battery based on the usage history and the manufacturing history of the lithium-ion battery. In this way, if the cause of the abnormality in the lithium-ion battery is identified based on history information including not only the usage history but also the manufacturing history, the cause of the abnormality can be traced back not only to the usage stage but also to the manufacturing stage. This contributes greatly 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. In addition, 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 electricity storage system BSS includes a storage container SC, a plurality of battery modules BM, a blower device CM, a heater device 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 may be configured 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 of the battery module BM and includes a heating element that generates heat when current is applied. 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 blower device 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 the 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 performs charging control of the multiple battery modules BM based on the battery state 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 the like or power during a time period when electricity rates are low.

[0203] Further, 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 through the notification device ND.

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

[0205] Furthermore, once a battery breaks down, it may not be possible to store the generated energy until it becomes widespread, which may cause significant damage to users and businesses. Therefore, in order 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 early signs of battery failure, such as internal short circuits, 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 possible 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 method is a control method that focuses only on the battery temperature, and depending on the charge / discharge rate of the battery, it may not be necessary to heat the battery. Also, if the focus is only on the battery temperature, the battery temperature may be controlled excessively, resulting in excessive use of the power stored in the battery. In addition, in the case of a large-scale energy storage facility such as a large-capacity energy storage system BSS, the temperature distribution of the battery becomes complex, making it difficult to properly grasp the battery temperature. Also, it is difficult to detect battery failures such as internal short circuits early with only the temperature information of the lithium-ion battery, and the system may break down before the operator has time to secure the appropriate maintenance man-hours, which may result in a significant amount of downtime. The charge / discharge rate is the speed of charging and discharging.

[0208] Taking these into consideration, the battery control device 140 is configured to heat the lithium ion battery in accordance with the amount of lithium deposition during charging control. Note that lithium deposition may occur during times other than charging control. For this reason, it is desirable for the battery control device 140 to heat the lithium ion battery in accordance with the amount of lithium deposition, not limited to charging control.

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

[0210] As described above, lithium precipitation occurs not only during low-temperature charging, but also during high-capacity charging, overcharging, etc. In such situations as high-capacity charging and overcharging, the battery temperature of the battery module BM may be high to a certain extent.

[0211] For this reason, the battery control device 140 may be configured to heat the lithium ion battery in accordance with the amount of lithium precipitation 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 precipitation increases beyond a first precipitation 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 a battery abnormality using the alarm device ND.

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

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

[0215] The rest is the same as in the first embodiment. The battery management unit BMU of this embodiment can obtain the same effects as in the first embodiment, which are achieved by a configuration common to the first embodiment or an equivalent configuration.

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

[0217] (1) When the amount of lithium precipitation increases beyond a predetermined threshold, the battery management unit BMU heats the battery module BM using the heater device HM that heats the battery module BM. By heating the lithium ion battery at the timing when the amount of lithium precipitation increases, the increase in the amount of lithium precipitation is appropriately suppressed, so that the lithium ion battery can be used in a safe and highly efficient manner. In particular, the battery management unit of the present invention is suitable for a large-scale power storage facility where the temperature distribution is likely to expand.

[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 by the heater device HM when the amount of lithium deposition increases beyond a predetermined threshold and the battery temperature falls to or below a predetermined low temperature threshold. This also allows the lithium ion battery to be used in a safe and highly efficient manner.

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

[0221] In the third embodiment, the heating element is configured by the heater device HM, but the present invention is not limited to this, and the heating element may be configured by a load device around the battery. Also, the heating element may be heated by power supply 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 to 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. For this reason, the deposition amount detection unit 37 may calculate the amount of lithium deposition by referring to a control map that specifies the correlation between the amount of lithium deposition, the charge rate, and the battery temperature, as shown in FIG. 33, for example. This also applies to other embodiments.

[0223] (Fourth embodiment) Next, a fourth embodiment will be described with reference to Fig. 34 and Fig. 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 need to be transported safely. For example, international regulations stipulate packaging standards for transportation by aircraft according to the lithium content. Batteries used in electric vehicles contain a large amount of lithium, so transportation by aircraft is difficult due to regulations, and ocean transport by ship is common. Compared to air transport, ocean transport takes a long time. For example, in summer, the transport takes a long time in high temperature and high humidity conditions, and in winter, the transport takes a long time in low temperature conditions. Under such stressful conditions, once a lithium-ion battery transitions to an unsafe state, it becomes difficult to control the lithium-ion battery, and there is a risk of damage to other cargo and passengers, so it is important to monitor the safety state of the lithium-ion battery.

[0225] In response to this, it is conceivable that lithium-ion batteries could be transported using a transport container made of non-flammable materials and equipped with a cooling mechanism, and if a battery unsafe event is detected using gas sensor 35, the lithium-ion battery could be inactivated using 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, and when the gas sensor 35 is used to detect an unsafe event in the battery as in the above-mentioned method, the chain reaction has already started when gas is released from the lithium-ion battery. Since the chain reaction progresses rapidly, it is difficult to inactivate the lithium-ion battery at such a time. In addition, 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 an abnormal heat generation phenomenon in which the battery temperature continues to rise unintentionally, and to detect an abnormal condition that occurs in the battery at an early stage of the occurrence 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, the gas sensor 35, and the 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 in the storage container SC to detect vibrations and impacts applied to the storage container SC. 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. 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 the abnormal heat generation phenomenon based on the monitoring result of factors that lead to the abnormal heat generation phenomenon, detects an abnormal state occurring in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the detection result of the abnormal state. The abnormality detection unit 150 is configured in the same manner 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] In order to prevent and detect abnormal heat generation at an early stage, the abnormality detection unit 150 executes the control process shown in Fig. 12 described in the first embodiment. In addition, the abnormality detection unit 150 executes the external notification process and the battery protection process described in the first embodiment as measures against the abnormal heat generation.

[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 at least one of the sensor outputs of the temperature sensor 31, the humidity sensor HS, and the acceleration sensor GS, and the location information of the battery module BM where the abnormal heat generation phenomenon occurred. This is because it becomes easier to clarify the location of responsibility 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] The rest is the same as in the first embodiment. The battery transport device BSC of this embodiment can obtain the same effects as in the first embodiment that are achieved by a configuration common to the first embodiment or an equivalent configuration.

[0235] Moreover, the battery transport device BSC of this embodiment 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 an abnormal heat generation phenomenon in which the temperature of the battery continues to rise unintentionally, and an abnormality detection unit 150 that detects abnormalities in the battery. The abnormality detection unit 150 suppresses the occurrence of the abnormal heat generation phenomenon based on the monitoring results of the factor monitoring unit, detects an abnormal state that occurs in the battery at an early stage of the occurrence of the abnormal heat generation phenomenon, and implements measures against the abnormal heat generation phenomenon based on the detection result of the abnormal state. This makes it possible to implement effective heat countermeasures when transporting the battery, such as preventing the occurrence of the abnormal heat generation phenomenon, and implementing measures from the early stage of the occurrence, even if the abnormal heat generation phenomenon 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 is not the same as 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 described below.

[0239] In the above-described battery evaluation system BRS and battery evaluation method, the safety evaluation of the battery module BM based on the amount of lithium deposition is essential, but measures against abnormal heat generation in the battery, for example, are not essential.

[0240] The battery evaluation system BRS and the battery evaluation method need only be capable of performing at least an evaluation of safety based on the amount of lithium deposition, and are not required to perform calculations of value, proposals of uses, safety rankings, whether or not the battery can be reused, and determination of the optimal combination according to the use.

[0241] Furthermore, the battery state information only needs to include information on at least the amount of lithium deposition, and does not need to include deterioration information such as the volume ratio SOH, the use of the battery module BM, or the usage history of the battery module BM.

[0242] The evaluation target of the above-mentioned battery evaluation system BRS and the battery evaluation method is not limited to an on-board battery mounted on a vehicle. The battery evaluation system BRS and the battery evaluation method can also be used to evaluate, for example, a stationary storage battery or a portable storage battery.

[0243] The battery monitoring device 20 described above includes a flexible substrate FPC and an ASIC circuit, but is not limited to this. The flexible substrate FPC and the ASIC circuit are not essential components of the battery monitoring device 20.

[0244] As in the above 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.

[0245] As in the above-described embodiment, it is desirable for the battery monitoring device 20 to compare a predetermined battery state estimated from the amount of lithium deposition with a predetermined battery state estimated from other elements to diagnose the suitability of the deposition amount detection unit 37, but this is not essential.

[0246] In the above embodiment, the volumetric rate SOH is estimated based on the amount of lithium precipitation and the thickness of the SEI layer of the battery, but the volumetric rate SOH may be estimated based on other physical quantities. The battery monitoring device 20 may detect a deterioration state of the battery, including cracks in the positive electrode, and calculate the volumetric rate SOH based on the deterioration state.

[0247] As in the above embodiment, it is preferable 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 essential. 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.

[0248] 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.

[0249] The battery monitoring device 20 basically monitors lithium ion batteries, but is not limited to this and can monitor any battery that may have similar issues to lithium ion batteries. Note that the battery monitored by the battery monitoring device 20 does not have to be one in which multiple battery cells C are modularized.

[0250] 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.

[0251] In the above-described embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential, except in cases where it is particularly expressly stated that they are essential or where they are clearly considered to be essential in principle.

[0252] 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 it is specifically stated as required or unless it is clearly limited to a specific number in principle.

[0253] In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., there is no limitation to those shapes, positional relationships, etc., unless specifically stated or in principle limited to a specific shape, positional relationship, etc.

[0254] The control unit and the method of the present disclosure may be implemented in a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. The control unit and the method of the present disclosure may be implemented in a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. The control unit and the method of the present disclosure may be implemented in one or more special-purpose computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. The computer program may also be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer.

[0255] [Features of this disclosure] The present disclosure has the following features.

[0256] [Disclosure 1] A battery evaluation system for evaluating a storage battery (BM) including a lithium ion battery, a battery monitoring unit (20) that monitors a battery state of the storage battery; an evaluation device (130) that acquires battery state information including a monitoring result of the battery state from the battery monitoring unit and evaluates the storage battery based on the battery state information; the battery monitoring unit is configured to be able to calculate an amount of lithium deposition in the lithium ion battery as an index indicating the battery state, The evaluation device determines the safety of the storage battery based on the amount of lithium deposition.

[0257] [Disclosure 2] The battery evaluation system according to Disclosure 1, wherein the evaluation device includes a value calculation unit (132) that calculates a value of the storage battery by taking into account a result of the judgment on the safety of the storage battery.

[0258] [Disclosure 3] The battery evaluation system according to Disclosure 1 or 2, wherein the evaluation device includes an application suggestion unit (133) that suggests an application of the storage battery when it is reused, taking into account the judgment result of the safety of the storage battery.

[0259] [Disclosure 4] The battery evaluation system according to any one of Disclosures 1 to 3, wherein the evaluation device ranks the safety of each of the plurality of lithium ion batteries included in the storage battery based on the amount of lithium deposition.

[0260] [Disclosure 5] The battery evaluation system according to any one of Disclosures 1 to 4, wherein the evaluation device includes a reuse determination unit (134) that determines whether the lithium ion batteries can be reused, taking into account the safety of each of the plurality of lithium ion batteries.

[0261] [Disclosure 6] The battery evaluation system according to any one of Disclosures 1 to 5, wherein, when the reusable lithium-ion batteries are rearranged to rebuild a different battery, the evaluation device is provided with an information output unit (135) that outputs a combination of the lithium-ion batteries suitable for an application of the different battery as rebuild information, taking into account the safety of the lithium-ion batteries.

[0262] [Disclosure 7] The battery evaluation system according to any one of Disclosures 1 to 6, wherein the battery state information includes at least one of the purpose, usage history, and degradation state of the lithium ion battery in addition to the amount of lithium deposition.

[0263] [Disclosure 8] A battery evaluation method for evaluating a storage battery (BM) including a lithium ion battery, comprising: monitoring a battery state of the storage battery; acquiring battery state information including a result of monitoring the battery state, and evaluating the storage battery based on the battery state information; In the monitoring of the battery state, an amount of lithium deposition in the lithium ion battery is calculated as an index indicating the battery state; The battery evaluation method includes evaluating the storage battery, and determining safety of the storage battery based on the amount of lithium deposition. [Explanation of symbols]

[0264] 20 Battery monitoring device (battery monitoring section) 130 Evaluation device BRS Battery Rating System BM Battery Module (Storage Battery)

Claims

1. A battery evaluation system for evaluating a storage battery (BM) including a lithium ion battery, A battery monitoring unit (20) for monitoring a battery state of the storage battery; an evaluation device (130) that acquires battery state information including a monitoring result of the battery state from the battery monitoring unit and evaluates the storage battery based on the battery state information; the battery monitoring unit is configured to be able to calculate the amount of lithium deposition in the lithium ion battery as one index showing the battery state, and includes a diagnosis unit (541) that compares the battery state estimated from the amount of lithium deposition with the battery state estimated from factors other than the amount of lithium deposition to diagnose the suitability of a configuration for detecting the amount of lithium deposition, The evaluation device determines the safety of the storage battery based on the amount of lithium deposition.

2. The battery evaluation system according to claim 1 , wherein the evaluation device includes a value calculation unit (132) that calculates a value of the storage battery by taking into account a result of a safety assessment of the storage battery.

3. The battery evaluation system according to claim 1 , wherein the evaluation device includes an application suggestion unit (133) that suggests an application for the storage battery when it is reused, taking into account a result of the safety assessment of the storage battery.

4. The battery evaluation system according to claim 1 , wherein the evaluation device ranks the safety of each of the lithium ion batteries included in the storage battery based on the amount of lithium deposition.

5. The battery evaluation system according to claim 4 , wherein the evaluation device includes a reuse determination unit (134) that determines whether or not the lithium ion battery can be reused, taking into account the safety of each of the plurality of lithium ion batteries.

6. 6. The battery evaluation system according to claim 5, wherein, when the reusable lithium ion batteries are rearranged to rebuild a different battery, the evaluation device includes an information output unit (135) that outputs a combination of the lithium ion batteries suitable for an application of the different battery as rebuild information, taking into account the safety of the lithium ion batteries.

7. 7. The battery evaluation system according to claim 1, wherein the battery state information includes at least one of an intended use, a usage history, and a deterioration state of the lithium ion battery in addition to the amount of lithium deposition.

8. A battery evaluation method for evaluating a storage battery (BM) including a lithium ion battery, comprising: monitoring a battery state of the storage battery; acquiring battery state information including a result of monitoring the battery state, and evaluating the storage battery based on the battery state information; In the monitoring of the battery state, the amount of lithium deposition in the lithium ion battery is calculated as one index showing the battery state, and the battery state estimated from the amount of lithium deposition is compared with the battery state estimated from factors other than the amount of lithium deposition to diagnose the suitability of a configuration for detecting the amount of lithium deposition; The battery evaluation method includes evaluating the storage battery, and determining safety of the storage battery based on the amount of lithium deposition.

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