Charging system and charger

Abstract

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

Description

[0001] Cross-references of related applications

[0002] This application is based on Japanese Patent Application No. 2022-104710 filed on June 29, 2022, the contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a charging system for a secondary battery including a lithium-ion battery and a charger. Background Art

[0004] Conventionally, as a charger for a battery pack including lithium-ion batteries, there is known a charger that performs preliminary charging at a current value lower than a normal charging current for a certain period after charging of the battery pack is started, and determines the charger by overdischarging (for example, see Patent Document 1).

[0005] Prior art literature

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent No. 5400333 Summary of the invention

[0008] However, if the battery is configured to be charged after starting to charge and then determining whether it is chargeable or not as in Patent Document 1, the time required for charging by the charger (i.e., charging time) becomes longer. This is not preferable because the battery cannot be used for a longer period of time or the user's waiting time increases.

[0009] An object of the present disclosure is to provide a charging system and a charger that can suppress an increase in charging time.

[0010] According to one viewpoint of the present disclosure,

[0011] A charging system comprising:

[0012] Chargers for batteries containing lithium-ion cells; and

[0013] Battery-side equipment that monitors battery status including the amount of lithium deposition in lithium-ion batteries,

[0014] The charger includes:

[0015] an information acquisition unit, which acquires battery information including the battery status from a battery-side device;

[0016] a charging determination unit that determines whether the storage battery is chargeable based on the battery information; and

[0017] The charging control unit charges the storage battery based on the determination result of the charging determination unit.

[0018] According to another aspect of the present disclosure,

[0019] A charger is a charger for a storage battery including a lithium-ion battery, comprising:

[0020] an information acquisition unit that acquires battery information including a battery status from a battery-side device that monitors a battery status including an amount of lithium deposition in a lithium-ion battery;

[0021] a charge determination unit that determines whether the storage battery can be charged based on the battery information; and

[0022] The charging control unit charges the storage battery based on the determination result of the charging determination unit.

[0023] If the charger determines whether the storage battery can be charged based on the battery information obtained from the battery-side device, the charging time of the storage battery can be shortened compared to determining whether the storage battery can be charged by performing preliminary charging.

[0024] In addition, the reference symbols in parentheses attached to each component etc. are used to show an example of the correspondence relationship between the component etc. and the specific component etc. described in the embodiment described later. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. 1 is a schematic diagram showing a battery pack to which the battery monitoring device according to the first embodiment is applied.

[0026] Figure 2 This is an explanatory diagram for explaining a lithium-ion battery.

[0027] Figure 3 This is a schematic diagram of the structure of a battery management unit including a battery monitoring device.

[0028] Figure 4 This is an explanatory diagram for explaining a battery monitoring device.

[0029] Figure 5 This is an explanatory diagram for explaining a deposition amount detection unit included in the battery monitoring device.

[0030] Figure 6 This is an explanatory diagram for explaining a method for calculating the amount of lithium deposition.

[0031] Figure 7 This is an explanatory diagram for explaining how to calculate the parasitic resistance value.

[0032] Figure 8 It is an explanatory diagram for explaining the flow of calculation of the amount of lithium deposition.

[0033] Fig. 9 This is an explanatory diagram for explaining the diagnosis of the deposition amount detection unit by the diagnosis unit.

[0034] Fig.10 It is an explanatory diagram for explaining a method of calculating the volumetric specific energy (SOH) of a battery.

[0035] Fig.11 This is a timing chart showing the output changes of various sensors before and after the occurrence of abnormal heating phenomenon.

[0036] Fig.12 This is a description for explaining the flow of control processing executed by the battery monitoring device.

[0037] Fig.13 This is a schematic diagram of the structure of a battery management system including a battery monitoring device.

[0038] Fig.14 This is a schematic diagram of the configuration of a charging system including a battery monitoring device.

[0039] Fig.15 It is an explanatory diagram for explaining the current and voltage during charging of a battery module in a charging system as a comparative example of the first embodiment.

[0040] Fig.16 This is an explanatory diagram for explaining the flow of a control process executed by the battery monitoring device when charging of a battery module is started.

[0041] Fig.17 It is an explanatory diagram for explaining the flow of control processing executed by the charger.

[0042] Fig.18 This is an explanatory diagram for explaining the flow of control processing executed by the battery monitoring device during charging of a battery module.

[0043] Fig.19 It is an explanatory diagram for explaining the current and voltage during charging of the battery module in the charging system according to the first embodiment.

[0044] Fig. 20 This is a schematic diagram of the battery evaluation system.

[0045] Fig.21 This is a schematic block diagram for explaining the value estimation and usage recommendation of battery modules by the battery evaluation system.

[0046] Fig. 22 This is an explanatory diagram for explaining reconstruction information generated by the battery evaluation system.

[0047] Fig.23 This is an explanatory diagram for explaining the manufacturing process until the battery pack is mounted on a vehicle.

[0048] Fig.24This is an explanatory diagram for explaining a part of the functions of the battery monitoring device according to the second embodiment.

[0049] Fig.25 This is an explanatory diagram for explaining the phase of lithium deposition in a lithium-ion battery.

[0050] Fig.26 It is a schematic configuration diagram of a large-capacity power storage system according to a third embodiment.

[0051] Fig. 27 This is an explanatory diagram for explaining the internal structure of the large-capacity power storage system.

[0052] Fig.28 This is a schematic system configuration diagram of a large-capacity power storage system.

[0053] Fig.29 It is an explanatory diagram for explaining temperature control of a large-capacity power storage system as a comparative example of the third embodiment.

[0054] Fig.30 It is an explanatory diagram for explaining temperature control of the large-capacity power storage system according to the third embodiment.

[0055] Fig.31 It is an explanatory diagram for explaining a modified example of temperature control.

[0056] Fig.32 This is an explanatory diagram for explaining the appropriate time to replace the battery.

[0057] Fig.33 This is an explanatory diagram for explaining the relationship between the charging rate and temperature and the amount of lithium deposition.

[0058] Fig.34 It is a schematic configuration diagram of battery transport equipment according to a fourth embodiment.

[0059] Fig.35 This is a schematic system structure diagram of a battery transport facility. DETAILED DESCRIPTION

[0060] Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. In addition, in the following embodiments, the same reference symbols are sometimes added to the parts that are the same or equivalent to the matters described in the previous embodiments, and their descriptions are omitted. In addition, in the embodiments, when only a part of the structural elements is described, the structural elements described in the previous embodiments can be applied to the other parts of the structural elements. In the following embodiments, as long as there is no particular obstacle in the combination, the embodiments can be partially combined with each other even if it is not particularly stated.

[0061] (First Embodiment)

[0062] In the present embodiment, first, regarding an example in which the battery monitoring device 20 and the battery monitoring method of the present disclosure are applied to a battery management unit (hereinafter also referred to as BMU) of a vehicle equipped with a battery pack 1 as a high-voltage battery, refer to Figures 1 to 13 Next, in the present embodiment, a charging system BCS and a battery evaluation system BRS including the battery monitoring device 20 will be described.

[0063] BMU has Figure 1 The battery pack 1 shown in the figure. The battery pack 1 has a sealed container 11 constituting an outer shell, and a plurality of battery modules BM, a battery monitoring device 20, and a battery ECU 100 are accommodated inside the sealed container 11. A high pressure protection valve HPV is provided in the sealed container 11 for discharging the gas existing inside to the outside when the pressure inside the sealed container becomes high. For the battery pack 1, each battery module BM is adjusted to an appropriate temperature by a temperature control device not shown in the figure.

[0064] A plurality of battery modules BM are power sources that are connected to electrical equipment such as a motor for driving a vehicle not shown in the figure and supply electric power to the electrical equipment. The plurality of battery modules BM are electrically connected in series. In addition, the plurality of battery modules BM is a battery pack in which a plurality of battery cells C are electrically connected in series. In addition, in the present embodiment, a battery pack 1 having three battery modules BM is illustrated, but the number of battery modules BM is not limited thereto and can be set to any number. The number of battery cells C constituting the battery module BM can also be set to any number. In addition, the battery modules BM can also be partially electrically connected in parallel. Hereinafter, the battery cells C and the battery modules BM are sometimes referred to simply as batteries. In addition, the battery module BM of the present embodiment is a storage battery including a lithium-ion battery.

[0065] The battery cell C is a secondary battery that can be charged and discharged. The battery cell C is composed of a lithium ion battery. For example, a lithium ion battery Figure 2 As shown in the figure, the battery is composed of lithium iron phosphate LFP, nickel / manganese / cobalt NMC as the positive electrode agent, and graphite as the negative electrode agent. In addition, in the lithium ion battery, for example, the positive electrode side collector is composed of aluminum, and the negative electrode side collector is composed of copper. The lithium ion battery thus constructed has the following characteristics: it has excellent charge and discharge cycle characteristics, and on the other hand, the electrode potential is very close to the lithium precipitation potential, and lithium is easily precipitated in the charged state.

[0066] like Figure 3As shown, the battery monitoring device 20 is electrically connected to each battery module BM via a connecting member 21. The connecting member 21 includes a flexible substrate FPC printed with a wiring pattern. The battery monitoring device 20 includes the same number of sensor units 30A, 30B, 30C as the number of battery modules BM and the same number of monitoring modules 50A, 50B, 50C as the number of battery modules BM. The basic structures of the sensor units 30A, 30B, 30C are the same, so they are not described individually, but are described collectively as the sensor unit 30. In addition, the basic structures of the monitoring modules 50A, 50B, 50C are the same, so they are not described individually, but are described collectively as the monitoring module 50.

[0067] The sensor unit 30 detects the battery state of each battery module BM. Figure 4 As shown, 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 precipitation amount detection unit 37, and a coating detection unit 38. At least a part of the various sensors constituting the sensor unit 30 is mounted on the flexible substrate FPC. In addition, it is not necessary for all the various sensors constituting the sensor unit 30 to be mounted on the flexible substrate FPC. However, the temperature sensor 31, the strain sensor 34, and the gas sensor 35 are preferably near the battery cell C, so it is desirable to mount them on the flexible substrate FPC.

[0068] The temperature sensor 31 is a sensor for detecting the battery temperature of the lithium-ion battery. Figure 1 As shown in FIG. 1 , a plurality of temperature sensors 31 are mounted on the flexible substrate FPC. The same number of temperature sensors 31 as the number of battery cells C or a slightly smaller number than the number of battery cells C are mounted on the flexible substrate FPC so that the battery temperature of all lithium-ion batteries constituting the battery module BM can be grasped. In addition, the battery temperature can also be estimated based on the measurement result of the internal impedance of the battery cell C. In this case, the unit for estimating the battery temperature functions as the temperature sensor 31.

[0069] 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, it is sufficient for the battery pack 1 to have only one current sensor 32 .

[0070] The voltage sensor 33 can detect the voltage of the battery module BM as the block voltage in addition to the detection function of the cell voltage of each battery cell C. The voltage sensor 33 can be composed of, for example, a flying capacitor type circuit that sequentially charges the cell voltage of each battery cell C to a capacitor and detects the voltage between the terminals of the capacitor as the cell voltage.

[0071] The strain sensor 34 is a sensor that detects strain of each battery cell C caused by gas generation inside each battery cell C. The strain of the battery cell C may be detected by another sensor such as an ultrasonic sensor instead of the strain sensor 34 .

[0072] The gas sensor 35 is a sensor for detecting gas leakage from each battery cell C. The gas sensor 35 is configured to detect at least one of hydrogen, carbon monoxide, carbon dioxide, and hydrogen fluoride generated when an abnormality occurs in the lithium ion battery, for example.

[0073] 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 composed of, for example, an atmospheric pressure range type pressure sensor using atmospheric pressure as a reference.

[0074] The deposition amount detection unit 37 detects lithium deposition in the lithium ion battery and estimates the lithium deposition amount based on the correlation between the amount of lithium deposition in the lithium ion battery and the behavior of the current and voltage when both ends of the lithium ion battery are short-circuited.

[0075] like Figure 5 As shown, the precipitation amount detection unit 37 includes: a short circuit 371 that temporarily short-circuits both ends of the lithium-ion battery to discharge; and a calculation unit 372 that estimates the lithium precipitation amount based on the behavior of the current and voltage when the lithium-ion battery is short-circuited by the short circuit 371. The short circuit 371 is installed on the flexible substrate FPC. In addition, the calculation unit 372 is installed on the monitoring module 50.

[0076] Although not shown, the short-circuit circuit 371 includes a short-circuit switch for short-circuiting both ends of the lithium-ion battery, a coil, and a capacitor. The internal resistance of the lithium-ion battery, the coil of the short-circuit circuit 371, and the capacitor constitute a self-resonant circuit.

[0077] The operator 372 extracts a resistance change component correlated with the amount of lithium deposition contained in a signal waveform of at least one of the current and voltage flowing through the short-circuit circuit 371 when both ends of the lithium-ion battery are short-circuited, and calculates an estimated value of the amount of lithium deposition based on the extracted component.

[0078] The above-described estimation method has a very simple configuration, and is a very useful method in that it can detect a specific battery degradation pattern by adjusting the frequency of discharge from the lithium-ion battery.

[0079] On the other hand, it is known that the internal resistance of lithium-ion batteries is several mΩ to several hundred mΩ, and is sometimes easily affected by interference such as temperature and parasitic impedance, and it is difficult to accurately calculate the amount of lithium deposition using the above estimation method. This is the result of in-depth research conducted by the inventors.

[0080] Taking this into consideration, the calculation unit 372 of the precipitation amount detection unit 37 is as follows: Figure 6 As shown, the estimated value is corrected using both the battery temperature detected by the temperature sensor 31 and the parasitic resistance value pre-stored in the storage unit 51 of the monitoring module 50 to calculate the amount of lithium deposition.

[0081] The parasitic resistance value is a part of the parasitic impedance generated between the lithium-ion battery and the short-circuit circuit 371. The parasitic resistance value changes according to the battery temperature. Therefore, the operator 372 corrects the parasitic resistance value stored in the storage unit 51 according to the battery temperature, and calculates the lithium deposition amount using the corrected parasitic resistance value. In addition, the operator 372 has the function of a calibration unit for correcting the estimated value of the lithium deposition amount in addition to the function of the estimation unit of the lithium deposition amount.

[0082] Here, regarding the parasitic resistance value, such as Figure 7 As shown in FIG. 1 , the precipitation amount detection unit 37 is connected to a calibration device CD having a known impedance Z before being connected to the lithium-ion battery to obtain the impedance. Specifically, Figure 8 As shown, the 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 storage unit 51 of the monitoring module 50. Next, the short circuit 371 is connected to the battery module BM, and the lithium deposition amount is calculated in this state.

[0083] The deposition amount detection unit 37 configured in this way can ensure robustness against parasitic impedance and temperature changes. This is very effective in detecting the amount of lithium deposition with high accuracy.

[0084] The short circuit 371 of this embodiment includes a coil, which is larger in size, so it is necessary to consider the carrying property and appropriately seek miniaturization. Miniaturization can be achieved, for example, by increasing the saturation magnetic flux density of the coil. As a specific method of miniaturization, for example, a coil made of a material with high magnetic flux density or a gap is provided to increase the saturation magnetic flux density can be cited.

[0085] The coating detection unit 38 detects the thickness of a coating formed at the interface between the negative electrode and the electrolyte when the lithium ion battery is charged. This coating is also called an SEI layer. SEI is the abbreviation of Solid Electrolyte Interphase.

[0086] The thickness of the SEI layer is correlated with the behavior of the current and voltage when the two ends of the lithium-ion battery are short-circuited by the short-circuit circuit 371. The coating detection unit 38 estimates the thickness of the SEI layer based on the behavior of the current and voltage when the two ends of the lithium-ion battery are short-circuited by the short-circuit circuit 371. Specifically, the coating detection unit 38 extracts a component that is correlated with the thickness of the SEI layer contained in the signal waveform of at least one of the current and voltage flowing through the short-circuit circuit 371 when the two ends of the battery are short-circuited by the short-circuit circuit 371, and estimates the thickness of the SEI layer based on the extracted component. In addition, when detecting the thickness of the SEI layer, it is desirable to perform correction using the battery temperature in the same manner as the detection of the amount of lithium deposition.

[0087] Here, the amount of lithium precipitation and the thickness of the SEI layer are physical quantities that are highly correlated with the capacity degradation of the battery compared to the voltage and current of the battery. In the present embodiment, the precipitation detection unit 37 and the coating detection unit 38 constitute a "deterioration detection unit" that detects a physical quantity that is highly correlated with the capacity degradation of the battery compared to the voltage and current of the battery. In addition, the amount of lithium precipitation is one of the factors that cause the abnormal heating phenomenon in which the temperature of the battery continues to rise unintentionally. Therefore, the precipitation detection unit 37 constitutes a "factor monitoring unit" that monitors the factors that cause the abnormal heating phenomenon.

[0088] like Figure 4 As shown, a battery state detection unit 39 for detecting the battery state is installed in the flexible substrate FPC. The battery state detection unit 39 detects the battery state of excessive temperature rise, overcharge, and a battery state of a large change in internal resistance based on the sensor outputs of the temperature sensor 31, the current sensor 32, and the voltage sensor 33, for example.

[0089] Next, the monitoring module 50 will be described. The monitoring module 50 is an auxiliary module directly mounted on the battery module BM. The monitoring module 50 is a device located on the high voltage side in the BMU. The monitoring module 50 constitutes an "abnormality detection unit" that is electrically connected to the battery to detect abnormalities in the battery.

[0090] 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, monitoring results of the battery module BM, and the aforementioned parasitic resistance value. The storage unit 51 is composed of a non-transitory physical storage medium.

[0091] The wireless communication unit 52 is a communication device for enabling bidirectional communication with the battery ECU 100. The monitoring module 50 receives various signals from the battery ECU 100 and transmits monitoring results and the like of the monitoring module 50 to the battery ECU 100.

[0092] 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. In addition, the change in the internal resistance of the battery is one of the factors that cause abnormal heating. Therefore, the internal resistance detection unit 53 constitutes a "factor monitoring unit" that monitors the factors that cause abnormal heating.

[0093] The monitoring IC 54 is electrically connected to the battery to detect abnormalities of the battery. The monitoring IC 54 suppresses the occurrence of abnormal heating phenomena based on the monitoring results of factors causing abnormal heating phenomena, detects abnormal conditions generated in the battery at the initial stage of the occurrence of abnormal heating phenomena, and implements countermeasures against the abnormal heating phenomena based on the detection results of the abnormal conditions.

[0094] The monitoring IC 54 includes an ASIC circuit having an algorithm for monitoring factors that cause abnormal heating and detecting at least a part of an abnormal state generated in the battery at the initial stage of the abnormal heating. Specifically, the monitoring IC 54 is configured to include a diagnosis unit 541, an SOH estimation unit 542, and a monitoring control unit 543 as functional units that perform various controls.

[0095] The lithium deposition amount is a parameter that largely affects the residual value of the battery, so the verification of the reliability of this parameter is also important. The diagnosis unit 541 compares the battery state estimated based on the lithium deposition amount with the battery state estimated based on other factors other than the lithium deposition amount to diagnose the suitability of the deposition amount detection unit 37.

[0096] The diagnosis unit 541 is, for example, Fig. 9 As shown, the battery volume rate SOH is estimated based on the lithium deposition amount detected by the deposition amount detection unit 37. In addition, the diagnosis unit 541 estimates the battery volume rate SOH based on the sensor outputs of the temperature sensor 31, the current sensor 32, and the voltage sensor 33. In addition, SOH is an abbreviation for State of Health.

[0097] Next, the diagnosis unit 541 compares the volume ratio SOH estimated based on the amount of lithium deposition with the volume ratio SOH estimated based on the temperature, current, and voltage of the battery using a state comparator to diagnose whether the deposition amount detection unit 37 is appropriate or not. For example, if the deviation between the volume ratio SOH estimated based on the amount of lithium deposition and the volume ratio SOH estimated based on the temperature, current, and voltage of the battery is within a prescribed range, the diagnosis unit 541 diagnoses that the deposition amount detection unit 37 is appropriate. On the other hand, if the deviation between the volume ratio SOH estimated based on the amount of lithium deposition and the volume ratio SOH estimated based on the temperature, current, and voltage of the battery exceeds a prescribed range, the diagnosis unit 541 diagnoses that the deposition amount detection unit 37 is inappropriate. When the deposition amount detection unit 37 is diagnosed as inappropriate, the monitoring IC 54 prohibits the detection of the amount of lithium deposition and the control process using the amount of lithium deposition, or sends a signal indicating a failure of the deposition amount detection unit 37 to the battery ECU 100 via the wireless communication unit 52. In the present embodiment, the battery volume ratio SOH is exemplified as the battery state estimated by the diagnosis unit 541 , but the diagnosis unit 541 may estimate a battery state other than the volume ratio.

[0098] Here, a method for calculating the full charge capacity of a battery is disclosed in Japanese Patent Gazette No. 2014-102076. In this calculation method, first, the change in charge and discharge capacity between a first time point and a second time point is calculated by time-integrating the current value of the output current of the battery. Then, the OCV at the first time point and the second time point is measured, and the remaining capacity SOC at the first time point and the second time point is calculated using the SOC-OCV curve to calculate the change ΔSOC calculated as the deviation of the remaining capacity SOC at each time point. Next, the full charge capacity of the battery is calculated by dividing the change in charge and discharge capacity by the change ΔSOC of the remaining capacity SOC. In addition, the volumetric rate SOH of the battery is obtained by dividing the full charge capacity of the above-mentioned battery by the initial value of the full charge capacity.

[0099] However, in the above-mentioned calculation method of the remaining capacity SOC and the volume rate SOH, in order to avoid the influence of the error of the current sensor 32 and the voltage sensor 33, the charge and discharge amount of the battery cannot be calculated unless a certain degree of charge and discharge amount is generated, which lacks real-time performance and has problems in practicality. In addition, there is also the following problem: when calculating the charge and discharge amount, due to the offset error of the current sensor 32, the calculation error of the volume rate SOH is amplified over time.

[0100] Taking this into consideration, SOH estimation unit 542 estimates the volume fraction SOH of the battery based on a physical quantity that has a higher correlation with battery capacity degradation than the battery voltage and current. SOH estimation unit 542 constitutes a "volume fraction estimation unit."

[0101] One of the main causes of battery degradation is the increase in the internal resistance of the battery. The internal resistance of the battery has a strong correlation with physical quantities such as the amount of lithium precipitation and the internal resistance of the battery. In addition, the internal resistance of the battery is temperature-dependent and affects the current and voltage of the battery.

[0102] Taking these into consideration, the SOH estimation unit 542 of this embodiment is as follows Fig.10 The volumetric rate SOH is estimated 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. 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. In addition, the estimation model may also be a model obtained by deep learning, reinforcement learning, or deep reinforcement learning using a neural network, for example.

[0103] This makes it possible to perform real-time battery state diagnosis, which is difficult to perform by estimating the volume ratio SOH based on the charge and discharge amount. In addition, by accurately measuring the temperature, the temperature influence of the internal resistance of the battery can be eliminated and the degradation information can be appropriately extracted, thereby improving the accuracy.

[0104] The monitoring control unit 543 suppresses the occurrence of abnormal heating phenomenon based on the monitoring result of the factors causing the abnormal heating phenomenon, detects the abnormal state generated in the battery at the initial stage of the occurrence of the abnormal heating phenomenon, and implements countermeasures against the abnormal heating phenomenon based on the detection result of the abnormal state. In addition, although not shown in the figure, the monitoring IC 54 controls the circuit that equalizes the voltage of the plurality of battery cells C, etc.

[0105] Next, the battery ECU 100 will be described. The battery ECU 100 is a main module in the BMU, and performs charge and discharge control of each battery module BM. The battery ECU 100 is a device located on the low voltage side in the BMU.

[0106] Specifically, the battery ECU 100 is composed of a microcomputer having 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 monitoring module 50A, 50B, and 50C via the wireless communication device 110. In addition, the battery ECU 100 is connected to various ECUs via a communication path such as CAN. As various ECUs, there can be mentioned an ECU for thermal management of a temperature control device for controlling a battery, an ECU of an HMI device mounted on a vehicle, etc. The battery ECU 100 can notify various battery states to the outside via the HMI device, etc.

[0107] The battery pack 1 thus constructed includes a battery that can be charged and discharged, such as a lithium-ion battery. In such a battery, a specific component inside the battery generates heat for some reason, and the heat further causes the heat of other components, and an abnormal heating phenomenon may occur in which the temperature of the battery continues to rise unintentionally. If such an abnormal heating phenomenon occurs, the thermal reliability of the battery is significantly reduced, which is not ideal. Therefore, in lithium-ion batteries, it is important to detect whether the battery has abnormal heating phenomenon to ensure thermal reliability.

[0108] Here, for the output changes of various sensors before and after the abnormal heating phenomenon, refer to Fig.11 Provide explanation. Fig.11 An example of the results of verification by the inventors of the present invention on the output changes of various sensors before and after the abnormal heating phenomenon is shown.

[0109] like Fig.11 As shown, at the stage before the abnormal heating phenomenon occurs, first, as a sign of battery abnormality, the gas pressure inside the battery cell increases and the volume of the battery begins to change. As a result, the output of the strain sensor 34 shows an increasing trend.

[0110] After that, when the volume change of the battery becomes larger, the battery is damaged and the gas inside the battery cell begins to leak. As a result, the output of the gas sensor 35 shows an increasing trend. In addition, when the battery is damaged, the gas pressure inside the battery decreases, and the output of the strain sensor 34 shows a decreasing trend.

[0111] In addition, although Fig.11 Although not shown, when the degradation of the battery progresses, lithium precipitation occurs inside the battery or the thickness of the SEI layer increases, so that the internal resistance of the battery increases.

[0112] When abnormal heating occurs, the battery temperature and the pressure inside the battery pack 1 (i.e., the pack internal pressure) rise sharply, and the battery voltage drops sharply. Furthermore, the output of the gas sensor 35 shows an increasing trend. These signs become prominent at the initial stage of abnormal heating.

[0113] Taking these into consideration, the battery monitoring device 20 executes a control process for preventing abnormal heating phenomena before they occur and detecting them at an early stage. Fig.12 Provide explanation.

[0114] Fig.12The control processing shown is performed periodically or irregularly by the battery monitoring device 20, for example, during the start of the vehicle and before a predetermined time has passed since the vehicle stopped. In addition, each process shown in this flowchart is implemented by each functional unit of the battery monitoring device 20. In addition, each step of implementing this process is also understood as each step of implementing the battery monitoring method.

[0115] like Fig.12 As shown, the battery monitoring device 20 reads various signals from the sensor unit 30 and the like in step S100. Then, the battery monitoring device 20 determines whether an abnormal heating phenomenon occurs in step S105. As described above, at the initial stage of the occurrence of the abnormal heating phenomenon, the battery temperature, the pack internal pressure, and the output of the gas sensor 35 rise sharply, and the battery voltage drops sharply. In view of this, the battery monitoring device 20 determines whether an abnormal heating phenomenon occurs based on the output of at least a part of the temperature sensor 31, the voltage sensor 33, the gas sensor 35, and the pack internal pressure sensor 36.

[0116] When abnormal heating is detected, the battery monitoring device 20 moves to step S110 to implement countermeasures against the abnormal heating, including external notification of the occurrence of abnormal heating and battery protection based on at least one of battery cooling and charge / discharge control.

[0117] In the external notification process, for example, a signal indicating the occurrence of abnormal heating is output to the battery ECU 100, and a device having a notification function such as an HMI device is activated via the battery ECU 100 to notify the user or battery manager of the occurrence of abnormal heating.

[0118] In the battery protection process, for example, a signal instructing battery cooling is output to the battery ECU 100, and the battery temperature control device is operated via the battery ECU 100 to cool the battery. By such battery cooling, the progress of abnormal heating of the battery can be delayed. In addition, in the battery protection process, for example, a signal instructing battery charging and discharging restriction is output to the battery ECU 100, and the battery self-heating is suppressed by restricting the operation of the battery. By such charge and discharge control, the progress of abnormal heating of the battery can also be delayed. The battery protection process constitutes an extension process for extending the life of the battery.

[0119] In addition, as one of the countermeasures for the abnormal heating phenomenon, the battery monitoring device 20 identifies an abnormal battery cell among the plurality of battery cells C as an abnormal cell based on at least one of the monitoring results of each of the plurality of battery cells C and the detection result of the abnormal state of the battery. In this way, the use of the abnormal cell can be restricted to delay the progress of the abnormal heating phenomenon.

[0120] In addition, the countermeasure against the abnormal heating phenomenon is not limited to the above-mentioned processing, and can also be implemented by processing other than the above-mentioned processing. The countermeasure against the abnormal heating phenomenon may be, for example, a countermeasure such as lighting a warning lamp or sounding an alarm.

[0121] On the other hand, when the occurrence of abnormal heating phenomenon is not detected, the battery monitoring device 20 transfers to the processing after step S115. In addition, the processing after step S115 is a processing for preventing the occurrence of abnormal heating phenomenon in advance.

[0122] The battery monitoring device 20 determines whether overcharge of the battery is detected in step S115. Overcharge of the battery can be detected by, for example, monitoring the sensor output of the voltage sensor 33. When overcharge of the battery is detected, the battery monitoring device 20 performs a charge suppression process in step S120 and returns to step S115. In the charge suppression process, charging of the battery is suppressed or discharging of the battery is performed.

[0123] If overcharge of the battery is not detected, the battery monitoring device 20 determines in step S125 whether excessive temperature rise of the battery is detected. Excessive temperature rise of the battery can be detected, for example, by monitoring the sensor output of the temperature sensor 31. If excessive temperature rise of the battery is detected, the battery monitoring device 20 implements output restriction and cooling control in step S130 and returns to step S115. In output restriction, for example, charging and discharging of the battery is suppressed. In cooling control, for example, the battery is cooled by a temperature control device of the battery.

[0124] If the excessive temperature rise of the battery is not detected, the battery monitoring device 20 determines whether lithium deposition is newly detected in step S135. Lithium deposition can be detected by monitoring the increase in the amount of lithium deposition detected by the deposition amount detection unit 37, for example.

[0125] When 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 / regeneration control, for example, the charging of the battery is suppressed. In heating control, for example, the battery is heated by a temperature control device of the battery. In addition, each process performed when lithium deposition is detected constitutes an extension process for extending the life of the battery.

[0126] If lithium deposition is not newly detected, the battery monitoring device 20 determines in step S145 whether a change in the internal resistance of the battery is detected. The internal resistance of the battery can be detected by, for example, monitoring the increase in the internal resistance detected by the internal resistance detection unit 53 .

[0127] When a change in the internal resistance of the battery is detected, the battery monitoring device 20 implements output limitation, temperature control, and notification of the degree of degradation of the battery 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 temperature of the battery is adjusted by the temperature control device so that the battery temperature is maintained in an appropriate range. In the notification of the degree of degradation, the degree of degradation of the battery is determined based on the internal resistance of the battery, and the determination result of the degree of degradation or the estimated replacement period of the battery based on the determination result is notified to the outside. In addition, each process implemented when a change in the internal resistance is detected constitutes an extension process for extending the life of the battery.

[0128] If the change in the internal resistance of the battery is not detected, the battery monitoring device 20 determines whether the deformation of the battery is detected in step S155 . The deformation of the battery can be detected by monitoring the sensor output of the strain sensor 34 .

[0129] When the deformation of the battery is detected, the battery monitoring device 20 limits the output of the battery in step S160 and returns to step S115. In the output control, for example, the charge and discharge of the battery are suppressed.

[0130] If no deformation of the battery is detected, it is considered that no sign of abnormal heating has been confirmed and the battery monitoring device 20 is in a normal state. Fig.12 The control process shown.

[0131] In addition, the electrification of vehicles is developing rapidly, and a large number of used batteries are expected to be generated in the near future. In order to manufacture batteries, a large amount of CO2 is discharged and rare metals are used. For used batteries, the remaining capacity SOC / volume ratio SOH of the battery is selected for reuse, reconstruction, and recycling, thereby expecting to build a battery ecosystem that is suitable for a recycling society. In order to build such a battery ecosystem, it is important to accurately diagnose the value of the battery such as the remaining capacity SOC / volume ratio SOH. In addition, it is envisaged that the battery is stored after the on-vehicle use ends until the secondary use destination is determined, but it is also envisaged that the battery continues to discharge when not in use, and deteriorates according to the storage status. Therefore, as a secondary user, it is necessary to grasp the remaining capacity SOC / volume ratio SOH of the battery at the moment, and the real-time performance of battery diagnosis becomes important.

[0132] As described above, the battery monitoring device 20 of this embodiment can calculate the remaining capacity SOC / volume rate SOH in real time. Considering this, it is expected that the battery module BM and the battery monitoring device 20 are circulated in the market as a battery unit UT. In addition, it is expected that, for example, Fig.13 The shown battery management system BMS manages the battery modules BM.

[0133] The battery management system BMS includes a battery monitoring device 20 mounted on 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.

[0134] The performance determination unit 61 determines whether the battery can be reused based on the volume ratio SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20. For example, the performance determination unit 61 determines that the battery can be reused if the volume ratio SOH estimated by the SOH estimation unit 542 is greater than a predetermined value, and determines that the battery cannot be reused if the volume ratio SOH estimated by the SOH estimation unit 542 is less than the predetermined value. In addition, the performance determination unit 61 may determine whether the battery can be reused based on a battery state other than the volume ratio SOH.

[0135] The value setting unit 62 determines whether the battery is abnormal based on the volumetric rate SOH estimated by the SOH estimating unit 542 of the battery monitoring device 20, and sets the residual value of the battery if the battery is abnormal. For example, the value setting unit 62 estimates the residual value of the battery to be lower as the volumetric rate SOH decreases. In addition, the value setting unit 62 may set the residual value of the battery based on a battery state other than the volumetric rate SOH.

[0136] The performance notification unit 63 determines whether the volume ratio SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20 is within the permissible range of the volume ratio SOH indicated in the specification data of the battery, and outputs the determination result to the outside.

[0137] The performance notification unit 63 acquires the specification data of the battery provided by the manufacturer of the battery, etc. and stores it in the memory. Then, for example, when the volume ratio SOH estimated by the SOH estimation unit 542 is within the allowable range shown in the specification data, the performance notification unit 63 notifies the seller, secondary user, etc. of the battery to that effect. In addition, for example, when the volume ratio SOH estimated by the SOH estimation unit 542 is outside the allowable range shown in the specification data, the performance notification unit 63 notifies the seller, secondary user, etc. of the battery that the secondary use of the battery is difficult.

[0138] According to the battery monitoring device 20 and the battery monitoring method described above, it is possible to implement effective countermeasures against abnormal heat generation, effective detection of the amount of lithium deposition, and effective estimation of the volume fraction SOH.

[0139] [Abnormal fever countermeasures]

[0140] The battery monitoring device 20 and the battery monitoring method monitor factors that cause abnormal heating phenomena, and based on the monitoring results of the factors, the occurrence of abnormal heating phenomena is suppressed before it occurs. In addition, the battery monitoring device 20 and the battery monitoring method detect abnormal conditions generated in the battery at the initial stage of the occurrence of abnormal heating phenomena, and implement countermeasures against the abnormal heating phenomena based on the detection results of the abnormal conditions. According to this, the occurrence of abnormal heating phenomena can be prevented before it occurs, and even if abnormal heating phenomena occur, effective thermal countermeasures can be implemented from the initial stage of its occurrence.

[0141] In addition, the battery monitoring device 20 can obtain the following effects.

[0142] (1) The monitoring module 50 of the battery monitoring device 20 performs monitoring of factors causing abnormal heating and detection of abnormal conditions of the battery in parallel. In other words, the monitoring module 50 performs detection of abnormal conditions of the battery independently of the monitoring result of factors causing abnormal heating. Thus, for example, compared with the case where abnormal conditions are detected after monitoring of factors causing abnormal heating, abnormal conditions can be detected earlier, and thus countermeasures against abnormal heating can be implemented earlier.

[0143] (2) The countermeasures for abnormal heating phenomenon include external notification processing to notify the outside of the occurrence of abnormal heating phenomenon, or battery protection processing based on at least one of battery temperature adjustment control and charge and discharge control. When the countermeasures for abnormal heating phenomenon include external notification processing, in addition to the countermeasures that can be taken by the battery monitoring device 20 itself, it is also easy to implement countermeasures performed by external devices of the battery monitoring device 20 and countermeasures in cooperation with external devices. In addition, when the countermeasures for abnormal heating phenomenon include battery protection processing, the battery can be appropriately protected.

[0144] (3) The monitoring module 50 performs a battery life extension process based on the monitoring result of the factor causing the abnormal heating phenomenon. If the battery life extension process is performed based on the monitoring result of the factor causing the abnormal heating phenomenon, the battery life can be appropriately extended.

[0145] (4) Factors causing abnormal heating include at least one of lithium deposition inside the battery and internal resistance of the battery. Lithium deposition inside the lithium-ion battery and an increase in internal resistance are the main causes of abnormal heating of the battery. Therefore, if lithium deposition and internal resistance are monitored, it is easy to suppress the occurrence of abnormal heating of the battery.

[0146] (5) The monitoring module 50 identifies an abnormal battery cell among the plurality of battery cells C as an abnormal cell based on at least one of the monitoring results of each of the plurality of battery cells C and the detection results of the abnormal state of the plurality of battery cells C. If the structure is such that the abnormal cell can be identified from the plurality of battery cells C, for example, the use of the abnormal cell can be restricted to suppress the occurrence of abnormal heating phenomenon before it occurs or to delay the progress of the abnormal heating phenomenon.

[0147] (6) The monitoring module 50 is configured to detect at least one of the abnormal internal pressure of the sealed container 11, the abnormal temperature of the battery, the abnormal voltage of the battery, and the abnormal gas in the sealed container 11 as an abnormal state of the battery. At the initial stage of the occurrence of the abnormal heating phenomenon, the internal pressure of the sealed container 11 that accommodates the battery, the temperature of the battery, the voltage of the battery, and the gas state in the sealed container 11 become abnormal. Therefore, if the monitoring module 50 is configured to detect at least one of the abnormal internal pressure of the sealed container 11, the abnormal temperature of the battery, the abnormal voltage of the battery, and the abnormal gas in the sealed container 11, it is easy to detect the abnormal heating phenomenon at the initial stage of occurrence.

[0148] (7) The battery monitoring device 20 includes an ASIC circuit having an algorithm for performing at least a part of monitoring factors causing abnormal heating and detecting abnormal conditions of the battery. Thus, monitoring factors causing abnormal heating and detecting abnormal conditions can be realized with a simple structure.

[0149] (8) The monitoring module 50 is configured to determine the degree of battery degradation based on the monitoring result of the factor causing abnormal heating phenomenon, and to notify the outside of the determination result of the degree of degradation or the replacement period of the battery estimated based on the determination result. If the configuration is set to determine the degree of battery degradation based on the monitoring result of the factor causing abnormal heating phenomenon, a dedicated device for determining the degree of battery degradation is not required. This contributes to the simplification of the battery monitoring device 20.

[0150] (9) The connection member 21 connecting the battery and the monitoring module 50 includes a flexible substrate FPC on which a part of the sensor unit 30 is mounted. If a part of the sensor unit 30 is mounted on the flexible substrate FPC constituting the connection member 21, the factors causing abnormal heating of the battery can be monitored at a position close to the battery.

[0151] [Detection of lithium precipitation amount]

[0152] The precipitation amount detection unit 37 of the battery monitoring device 20 calculates the estimated value of the lithium precipitation amount based on the change of at least one of the current and voltage when the two ends of the lithium ion battery are short-circuited by the short-circuit circuit 371. Then, the precipitation amount detection unit 37 corrects the estimated value of the lithium precipitation amount with the battery temperature. Accordingly, the influence of the battery temperature included in the estimated value of the lithium precipitation amount can be reduced to improve the detection accuracy of the lithium precipitation amount, so the reliability of the precipitation amount detection unit 37 can be ensured.

[0153] In addition, the deposition amount detection unit 37 corrects the estimated value of the lithium deposition amount using the parasitic resistance value stored in the storage unit 51. This can reduce the influence of the parasitic impedance included in the estimated value of the lithium deposition amount, improve the detection accuracy of the lithium deposition amount, and thus ensure the reliability of the deposition amount detection unit 37.

[0154] (1) Specifically, the deposition amount detection unit 37 corrects the parasitic resistance value stored in the storage unit 51 according to the battery temperature, and calculates the lithium deposition amount using the corrected parasitic resistance value. This can reduce the influence of the battery temperature and parasitic impedance included in the estimated value of the lithium deposition amount, thereby improving the detection accuracy of the lithium deposition amount.

[0155] (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 allows the parasitic resistance value of the deposition amount detection unit 37 to be obtained with high accuracy. This greatly contributes to improving the detection accuracy of the lithium deposition amount.

[0156] (3) The battery monitoring device 20 includes a diagnostic unit 541 that compares a predetermined battery state estimated based on the amount of lithium deposition with a predetermined battery state estimated based on other factors other than the amount of lithium deposition to diagnose the suitability of the deposition amount detection unit 37. Thus, the diagnostic unit 541 can diagnose the reliability of the deposition amount detection unit 37, thereby ensuring the reliability of the deposition amount detection unit 37.

[0157] [Modification of Battery Monitoring Device 20]

[0158] The battery monitoring device 20 may not be the same as the above-mentioned battery monitoring device, but may be partially different from the above-mentioned battery monitoring device. In addition, the above-mentioned technical matters can also be applied to devices and systems other than vehicle-mounted devices.

[0159] [Estimate of SOH]

[0160] The battery monitoring device 20 detects a physical quantity that is highly correlated with the capacity degradation of the battery compared to the voltage and current of the battery, and estimates the volumetric rate SOH of the battery based on the physical quantity. If the structure is set to estimate the volumetric rate SOH based on the physical quantity that is highly correlated with the capacity degradation of the battery, it is less necessary to avoid the influence of errors than in the case of calculating the volumetric rate SOH based on the current and voltage of the battery, so the volumetric rate SOH can be estimated in a short time. Therefore, according to the battery monitoring device 20 of the present case, the battery state can be grasped in a practical manner.

[0161] (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 rupture of the positive electrode active material inside the battery is a physical quantity that directly affects the capacity degradation of the battery. Therefore, by setting a structure that calculates the volumetric rate SOH not only based on the amount of lithium precipitation and the thickness of the SEI layer, but also based on the degree of rupture of the positive electrode active material, the detection accuracy of the volumetric rate SOH can also be improved. In addition, the degree of rupture of the positive electrode active material can be estimated based on the behavior of the current and voltage when the two ends of the lithium-ion battery are short-circuited, or the sensor output of the strain sensor or ultrasonic sensor.

[0162] (2) There is a correlation between the amount of lithium deposited in the lithium-ion battery, the thickness of the SEI layer, and the behavior of the current and voltage when the two 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 deposited and the thickness of the SEI layer based on the change in at least one of the current and voltage when the two ends of the lithium-ion battery are short-circuited by the short-circuit circuit 371.

[0163] (3) Specifically, the battery monitoring device 20 uses the battery temperature to correct at least one of the amount of lithium deposition and the thickness of the SEI layer. This can reduce the influence of the battery temperature included in the estimated value of the amount of lithium deposition and the thickness of the SEI layer, thereby improving the detection accuracy of the amount of lithium deposition and the thickness of the SEI layer.

[0164] (4) The battery management system BMS determines whether the battery can be reused based on the volume ratio SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20. Based on this, it is easy to determine whether to choose to reuse, rebuild, or recycle the battery when reusing it. This greatly contributes to the construction of a battery ecosystem that is suitable for a recycling-oriented society.

[0165] (5) The battery management system BMS determines whether the battery is abnormal based on the volume ratio SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20, and sets the residual value of the battery if the battery is abnormal. This makes it easy to determine whether to select reuse, reconstruction, or recycling when reusing the battery, thus contributing to the construction of a battery ecosystem that is suitable for a recycling-oriented society.

[0166] (6) The battery management system BMS determines whether the volumetric rate SOH estimated by the SOH estimation unit 542 of the battery monitoring device 20 is within the permissible range of the volumetric rate SOH indicated in the battery specification data, and outputs the result of the determination to the outside. This makes it easy to determine which of reuse, reconstruction, and recycling should be selected when the battery is reused, thus greatly contributing to the construction of a battery ecosystem that is suitable for a recycling-oriented society.

[0167] [Variation of Battery Management System BMS]

[0168] The battery management system BMS may not be the same as the above-mentioned battery management system, and a part of it may be different from the above-mentioned battery management system. In addition, the above-mentioned technical matters may also be applied to devices and systems other than vehicle-mounted devices.

[0169] The above is the description about the BMU etc. Next, the charging system BCS and the battery evaluation system BRS will be described.

[0170] [BCS Charging System]

[0171] For the following information about the BCS charging system, refer to Figures 14 to 19 The charging system BCS is a system for charging the battery modules BM included in the battery pack 1. The charging system BCS is applied to, for example, a charging station for a vehicle.

[0172] like Fig.14 As shown, the charging system BCS includes a battery monitoring device 20, a battery ECU 100, a charger 120, and a charging cable CC. In this embodiment, the battery monitoring device 20 and the battery ECU 100 included in the battery pack 1 constitute a battery-side device that monitors the battery state including the amount of lithium deposition in the lithium-ion battery.

[0173] The battery module BM is connected to the vehicle power control unit PCU and the motor generator MG via a switch SW2 such as a system main relay. When the vehicle start switch is turned on, for example, 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 to be chargeable and dischargeable.

[0174] The battery monitoring device 20 and the battery ECU 100 are basically configured in the same manner as in the case described above. The battery ECU 100 can communicate with the charger 120 via the communication device CE. When the battery ECU 100 becomes a state in which communication with the charger 120 is possible, the battery information including the battery state such as the amount of lithium deposition and the remaining capacity SOC is notified to the charger 120. In addition, the battery ECU 100 determines whether it is in a chargeable state, and notifies the charger 120 of the determination result as one of the battery information. In addition, the battery ECU 100 sets the target current amount during the charging period under constant current, that is, the CC charging current, and the target voltage during the charging period under constant voltage, that is, the CV charging voltage, and notifies the charger 120 of these setting values. In addition, the communication between the communication device CE and the charger 120 is performed via the CAN and the communication line included in the charging cable CC.

[0175] The charging cable CC is used to electrically connect 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.

[0176] The charger 120 is a device for charging the battery module BM. The charger 120 is composed of a device in accordance with charging standards such as CHAdeMO, CCS, GB / T, etc. A switch SW1 is provided between the charger 120 and the battery module BM to connect and disconnect the electrical connection between the charger 120 and the battery module BM. The switch SW1 can be provided on the charger 120 side or on the vehicle side.

[0177] The charger 120 includes an information acquisition unit 121, a charge determination unit 122, a charge control unit 123, and a charge time calculation unit 124. The information acquisition unit 121, the charge determination unit 122, the charge control unit 123, and the charge time calculation unit 124 are constituted by, for example, a microcomputer having a processor, a memory, an I / O, and the like.

[0178] The information acquisition unit 121 acquires battery information including battery status such as lithium deposition amount and remaining capacity SOC from the battery monitoring device 20 and the battery ECU 100 during charging of the battery module BM. The information acquisition unit 121 also acquires CC charging current and CV charging voltage from the battery ECU 100.

[0179] Here, the amount of lithium deposition is important information indicating the safety of the battery module BM. Therefore, the information acquisition unit 121 of this embodiment notifies the outside of the battery information including the information indicating the amount of lithium deposition through the notification device ND. The notification device ND includes, for example, a display, a speaker, a lamp, and other equipment.

[0180] The charge determination unit 122 determines whether the battery module BM is chargeable based on the battery information acquired by the information acquisition unit 121. For example, the charge determination unit 122 determines whether the battery module BM is chargeable based on the result of the determination of whether the battery module BM is in a chargeable state performed by the battery ECU 100. In addition, the charge determination unit 122 may determine whether the battery module BM is chargeable based on the amount of lithium deposition acquired by the information acquisition unit 121.

[0181] 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 the battery module BM can be charged, and does not charge the battery module BM when the determination result indicates that the battery module BM cannot be charged.

[0182] The charge 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 voltage after charging at a constant current. In the following description, charging at a constant current is sometimes referred to as CC charging, and charging at a constant voltage is sometimes referred to as CV charging.

[0183] The charging time calculation unit 124 estimates the required charging time required for charging based on the battery state acquired by the information acquisition unit 121, and notifies the information indicating the estimated required charging time to the outside through the notification device ND. The charging time calculation unit 124 can be configured to estimate the required charging time using a control map that specifies the relationship between the remaining amount of the battery module BM and the required charging time, for example. It is desirable that the charger 120, when notifying the required charging time to the outside through the notification device ND, includes the amount of time that can be shortened by this fast charging compared to the normal charging. In addition, it is desirable that the charger 120 notify the information terminal held by the user of the remaining time until the charging is completed.

[0184] The charging system BCS configured as described above is required to be able to charge at a higher speed with a higher energy density. Recently, the charger 120 has attempted to shorten the charging time of the battery module BM by supporting 50 kW in the CHAdeMO1.0 standard, 400 kW in the CHAdeMO2.0 standard, and 900 kW in the CHAdeMO3.0 standard.

[0185] The charging time can be shortened by increasing the charging output, but the increased charging current due to high-output charging accelerates the deposition of lithium at the negative electrode of the battery, which may significantly impair the life and safety of the battery.

[0186] To avoid this, consider adopting Fig.15As shown, the charging curve is a charging curve that avoids a deteriorated or unsafe state by performing preliminary charging with a small current before CC charging to detect abnormalities such as deep discharge of the battery.

[0187] However, if the pre-charging is performed for safety reasons, the charging time will be correspondingly longer, so the user may feel uncomfortable. In addition, if the charging time is longer than the user expected, the user may feel uneasy and anxious.

[0188] Taking these into consideration, the charging system BCS of the present embodiment is configured such that the charger 120 determines whether or not the battery module BM is chargeable based on the battery information acquired from the battery monitoring device 20 and the battery ECU 100 .

[0189] For the control process of the battery ECU 100 when charging of the battery module BM is started, refer to Fig.16 This control process is performed periodically or irregularly by the battery ECU 100. Fig.16 Each control step of the control process shown constitutes a function implementation unit that implements various functions executed by the battery ECU 100 .

[0190] like Fig.16 As shown, the battery ECU 100 determines in step S200 whether 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.

[0191] The battery ECU 100 executes an initial process in step S210. The battery ECU 100 initializes flags and the like, or acquires monitoring results of the battery monitoring device 20 in the initial process.

[0192] Next, the battery ECU 100 determines whether the battery module BM is in a chargeable state. For example, the battery ECU 100 determines that the battery module BM is chargeable if the amount of lithium deposition is within a specified value, and determines that the battery module BM is not chargeable if the amount of lithium deposition exceeds the specified value. In addition, the battery ECU 100 may also determine that the battery module BM is not chargeable in an overcharged state or a deep discharge state.

[0193] When the battery module BM can be charged, the battery ECU 100 sets the charge amount of the battery module BM in step S230. The battery ECU 100 obtains the charge amount of the battery module BM based on, for example, the remaining capacity SOC and the volume ratio SOH of the battery module BM. In addition, the battery ECU 100 sets the CV charging voltage in step S240. The battery ECU 100 sets, for example, the voltage value recommended as the charging voltage of the battery module BM as the CV charging voltage. And, the battery ECU 100 sets the CC charging current in step S250. The battery ECU 100 sets, for example, the 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 the battery information indicating the battery state including the amount of lithium deposition and various settings including the CV charging voltage and the CC charging current, and exits the present control process.

[0194] On the other hand, when the battery module BM cannot be charged, the battery ECU 100 notifies the charger 120 that the battery module BM cannot be charged in step S270, and exits the present control process.

[0195] Next, regarding the control process of the charger 120 when charging the battery module BM, refer to Fig.17 This control process is performed periodically or irregularly by the charger 120. Fig.17 Each control step of the control process shown constitutes a function implementation unit that implements various functions executed by charger 120 .

[0196] like Fig.17 As shown, the charger 120 determines in step S300 whether a notification from the battery ECU 100 is 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 moves to step S310. The charger 120 determines in step S310 whether the battery module BM can be charged based on the notification from the battery ECU 100. In addition, the process of step S310 is implemented by the charge determination unit 122 of the charger 120.

[0197] When the notification from the battery ECU 100 indicates that charging is not possible, the charger 120 notifies the outside of information indicating that the battery module BM cannot be charged and information indicating the amount of lithium deposition through the notification device ND in step S320, and does not charge the battery module BM.

[0198] On the other hand, when 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.

[0199] Next, the charger 120 determines in step S340 whether the voltage of the battery module BM has reached a predetermined voltage. This determination process is for determining whether it is a timing to switch from CC charging to CV charging. The predetermined voltage is set to, for example, a CV charging voltage.

[0200] When 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 setting update of the CC charging current has been received from the battery ECU 100 .

[0201] Here, the battery ECU 100 periodically or irregularly executes the following operations during CC charging: Fig.18 Specifically, Fig.18 As shown, the battery ECU 100 determines in step S500 whether the amount of lithium deposition is greater than a predetermined threshold value. The threshold value is set to a value that assumes the amount of lithium deposition that is deposited when the battery is abnormal. When the amount of lithium deposition is below the predetermined threshold value, the battery ECU 100 skips the subsequent steps and exits the setting update process, and transfers to step S510 when the amount of lithium deposition is greater than the predetermined threshold value. In step S510, the battery ECU 100 resets the CC charging current to be smaller than the current current. For example, the battery ECU 100 resets the current value before the amount of lithium deposition exceeds the predetermined threshold value as the CC charging current. Then, in step S520, the battery ECU 100 notifies the charger 120 of the setting update of the CC charging current.

[0202] Back to Fig.17 When the charger 120 receives the notification of the setting update of the CC charging current from the battery ECU 100, it updates the CC charging current to the current amount notified from the battery ECU 100 in step S360. That is, when the lithium deposition amount increases exceeding the predetermined threshold value during CC charging, the charger 120 reduces the current amount of the constant current. In addition, the processing of step S360 is implemented by the charging control unit 123 of the charger 120.

[0203] When the voltage of the battery module BM reaches a predetermined voltage, the charger 120 proceeds to step S370 to start CV charging. The charger 120 charges the battery module BM using the CV charging voltage set by the battery ECU 100 as a target voltage.

[0204] Next, in step S330 , the charger 120 determines whether the current flowing through the battery module BM is less than or equal to a predetermined value, or whether the elapsed time from the start of charging of the battery module BM is greater than or equal to a predetermined time.

[0205] When the current flowing through the battery module BM is greater than the specified value and the time elapsed from the start of charging is within the specified time, the charger 120 continues the CV charging. In addition, when the current flowing through the battery module BM is less than the specified value or the time elapsed from the start of charging exceeds the specified time, the charger 120 executes the charging end processing in step S390 and then exits the present control processing. In the charging end processing, for example, the user is notified of the completion of charging, the charge amount, the battery status, etc. through the notification device ND.

[0206] The charging system BCS described above includes a charger 120 including 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 charge determination unit 122 that determines whether the battery module BM can be charged based on the battery information, and a charge control unit 123 that charges the battery module BM based on the determination result of the charge determination unit 122. If the charger 120 determines whether 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 configuration in which the battery module BM can be charged by performing preliminary charging.

[0207] Furthermore, the charging system BCS of the present embodiment has the following features.

[0208] (1) The charging 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 voltage after charging at a constant current. Fig.19 As shown, when the amount of lithium deposition during CC charging increases beyond a predetermined threshold, the amount of constant current is reduced. This suppresses the amount of lithium deposition during CC charging, thereby ensuring the safety of the battery module BM and suppressing an increase in the charging time of the battery module BM.

[0209] (2) When charging using the charger 120 starts, the battery side device periodically determines whether the amount of lithium deposition increases by more than a threshold value. Then, when the amount of lithium deposition increases by more than a threshold value, the battery side device sets the target current amount during charging under 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 obtains the target current amount from the battery side device during CC charging, it adjusts the current amount of the constant current based on the target current amount. If a structure is formed in which the battery side device periodically monitors the amount of lithium deposition and adjusts the current amount suitable for charging under a constant current on the charger 120 side based on the monitoring result, the charging rate can be controlled to be maximized in a manner that does not cause lithium deposition. As a result, the waiting time of the user caused by the charging time can be appropriately shortened.

[0210] (3) The charger 120 estimates the required charging time based on the battery state and notifies the outside of information indicating the estimated required charging time via the notification device ND. This allows the user to understand the approximate waiting time, thereby reducing the user's psychological burden when charging the battery module BM.

[0211] (4) The charger 120 notifies the outside of the information indicating the amount of lithium deposition through the notification device ND. If not only the information indicating the required charging time but also the information indicating the amount of lithium deposition is provided to the user side, the user can also understand the safety of the lithium-ion battery, and the user's anxiety about the lithium-ion battery can be reduced.

[0212] [Modification of charging system BCS]

[0213] The charging system BCS may not be the same as the above-mentioned charging system, but may be partially different from the above-mentioned charging system. In addition, the above-mentioned technical matters can also be applied to equipment and systems other than vehicle-mounted equipment.

[0214] [Battery Rating System BRS and Battery Rating Method]

[0215] Lithium ion batteries sometimes precipitate lithium due to charging at low temperatures or high-speed charging. When lithium precipitation progresses, internal short circuits occur, which may cause fire / smoke. Therefore, when reusing storage batteries including lithium ion batteries, it is desirable to grasp not only the degree of deterioration but also the safety taking into account the degree of lithium precipitation.

[0216] Taking this into consideration, the battery evaluation system BRS and the battery evaluation method of the present embodiment determine the safety of the storage battery based on the amount of lithium precipitation. In addition, the battery evaluation system BRS functions as an auxiliary system for assisting the reuse and reconstruction of the battery module BM. Figure 20 to Figure 22 Provide explanation.

[0217] like Fig. 20 As shown, the battery evaluation system BRS includes a battery monitoring device 20 as a battery monitoring unit that monitors the battery state of the battery module BM and an evaluation device 130 that evaluates the battery module BM.

[0218] The battery monitoring device 20 is basically configured in the same manner as described above. The battery monitoring device 20 is configured to be able to calculate the amount of lithium precipitation in the lithium-ion battery included in the battery module BM as an indicator of the battery state. The battery monitoring device 20 can output battery state information including the monitoring results of the battery state including the amount of lithium precipitation to the outside by using the wireless communication unit 52 of the monitoring module 50. In addition to the amount of lithium precipitation, the battery state information also includes battery form information indicating the purpose of the battery module BM, the usage history of the battery module BM, etc. In addition, the battery monitoring device 20 can also be configured to be able to output the battery state information to the outside through a communication device other than the wireless communication unit 52 of the monitoring module 50.

[0219] The evaluation device 130 is configured to be able to communicate with the battery monitoring device 20, a data center storing market trading information of recycled batteries, and information terminals UA, UB, UC, etc. owned by users, sellers, secondary users, etc. via a wired or wireless communication network. The evaluation device 130 obtains battery status information from the battery monitoring device 20 and evaluates the battery module BM based on the battery status information. The evaluation device 130 of this embodiment includes a safety determination unit 131, a value estimation unit 132, a use suggestion unit 133, a reuse determination unit 134, and an information output unit 135.

[0220] The safety determination unit 131 determines the safety of the battery module BM based on the lithium deposition amount of the lithium ion batteries included in the battery module BM. The safety determination unit 131 determines that the safety is higher when the lithium deposition amount is smaller, and the safety determination unit 131 determines that the safety is lower when the lithium deposition amount is larger. If the battery module BM includes even one lithium battery that lacks safety, the safety of the battery module BM will be impaired. Therefore, the safety determination unit 131 can implement the classification of the safety of each of the plurality of lithium ion batteries included in the battery module BM based on the lithium deposition amount.

[0221] The value estimating unit 132 estimates the value of the battery module BM by taking into account the determination result of the safety of the battery module BM. For example, the value estimating unit 132 calculates the value by assuming that a battery module BM with high safety is more expensive than a battery module BM with low safety.

[0222] The value estimation unit 132 may be, for example, Fig.21As shown, the degradation state based on the volume ratio SOH, the safety based on the amount of lithium precipitation, the battery form information including the purpose, and the usage history are obtained from the battery monitoring device 20, and the market trading information of the recycled battery is obtained from the data center. Then, the value estimation unit 132 calculates the purchase price of the battery module BM based on the degradation state, safety, battery form information, usage history, and market trading information. The value estimation unit 132 calculates the purchase price of the battery module BM based on the information obtained from the battery monitoring device 20 and the data center, for example, with reference to a mapping diagram that associates the degradation state, safety, battery form information, usage history, market trading information, and the purchase price of the battery module BM. In addition, the value estimation unit 132 can also calculate the sales price of the battery module BM.

[0223] The use suggestion unit 133 takes into account the determination result of the safety of the battery module BM and suggests a transition use of the battery module BM during the reuse. Fig.21 As shown in the figure, the recommended use of the battery module BM when being reused is suggested based on the degradation state, safety, battery form information, and usage history. The use suggestion unit 133 refers to a map that associates the degradation state, safety, battery form information, usage history, and the use when being reused, and finds the recommended use of the battery module BM when being reused based on the information obtained from the battery monitoring device 20.

[0224] The reuse determination unit 134 determines whether the lithium-ion batteries can be reused, taking into account the safety of each of the plurality of 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 deposition is less than a predetermined value, and determines that the lithium-ion batteries cannot be reused if the amount of lithium deposition exceeds the predetermined value.

[0225] When the information output unit 135 reassembles the reusable lithium-ion battery to rebuild a different battery, such as Fig. 22 As shown, the safety of lithium-ion batteries is taken into consideration, and combinations of lithium-ion batteries suitable for different battery applications are output as reconstruction information.

[0226] Here, the optimal combination of lithium-ion batteries may differ depending on how the rebuilt battery is used. Therefore, it is desirable that the information output unit 135 outputs a combination corresponding to how the rebuilt battery is used to the rebuilding system RS that manufactures the rebuilt battery. For example, when the rebuilt battery is used for a long time such as a stationary type, the information output unit 135 outputs a combination with a long life and high safety as the rebuilding information. In addition, when the rebuilt battery is used for a short period of time, the information output unit 135 outputs a combination that emphasizes matters other than life as the rebuilding information.

[0227] 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 the 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 determines the safety of the battery module BM based on the amount of lithium precipitation. Based on this, the index related to the safety of the battery module BM such as the lithium precipitation state is determined, so that the evaluation including whether the safety requirements are met can be appropriately performed.

[0228] Furthermore, the battery evaluation system BRS and the battery evaluation method of the present embodiment have the following features.

[0229] (1) The evaluation device 130 includes a value estimating unit 132 that estimates the value of the battery module BM in consideration of the determination result of the safety of the battery module BM. This allows the user to be provided with an appropriate value of the battery module BM as information.

[0230] (2) The evaluation device 130 includes a usage suggestion unit 133 that suggests a usage of the battery module BM when recycling the battery module BM in consideration of the determination result of the safety of the battery module BM. This allows the user to be provided with appropriate usage of the battery module BM as information.

[0231] (3) The evaluation device 130 performs safety classification of each of the plurality of lithium-ion batteries included in the battery module BM based on the amount of lithium deposition. This allows the user to be provided with appropriate status information of the plurality of lithium-ion batteries constituting the battery module BM.

[0232] (4) The evaluation device 130 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. This makes it easier to reuse safe lithium-ion batteries in the battery module BM even when the entire battery module BM cannot be reused.

[0233] (5) When reusing lithium-ion batteries to rebuild a battery different from the battery module BM, the evaluation device 130 takes the safety of the lithium-ion batteries into consideration and outputs a combination of lithium-ion batteries suitable for different battery uses as reconstruction information. Thus, even when the entire battery module BM cannot be reused, it is easy to construct a different storage battery for reuse using the safe lithium-ion batteries in the battery module BM.

[0234] (6) 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. If the battery module BM is evaluated using various information in this way, the battery module BM can be evaluated in many aspects.

[0235] [Variation of Battery Evaluation System BRS and Battery Evaluation Method]

[0236] The battery evaluation system BRS and the battery evaluation method may not be the same as the above-mentioned system and method, but may be partially different from the above-mentioned system and method. In addition, the above-mentioned technical matters may also be applied to devices and systems other than vehicle-mounted devices.

[0237] (Second Embodiment)

[0238] Next, regarding the second embodiment, refer to Figure 23 to Figure 25 In the present embodiment, an example is described in which a cause of occurrence of an abnormality in the battery module BM is identified based on the usage history and manufacturing history of the battery module BM.

[0239] First, regarding the manufacturing process before the battery pack 1 is mounted on the vehicle, refer to Fig.23 For explanation. Fig.23 As shown, 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 1 into the vehicle.

[0240] In the manufacturing process of the battery cell C, electrode body formation, cell assembly, electrolyte injection, initial charge and discharge, and performance inspection are performed in this order. In the performance inspection, for example, the appearance inspection, foreign matter inspection, and battery characteristic inspection of the battery cell C are performed by inspection equipment.

[0241] Here, lithium ions are sometimes reduced and precipitated at the negative electrode of a lithium-ion battery. In particular, when charging is performed with a large current or in a low-temperature region, 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 completely enter the negative electrode active material and are easily precipitated on the negative electrode surface. If lithium is precipitated at the negative electrode, the amount of lithium ions that contribute to the battery reaction is reduced, which may cause a decrease in capacity or an internal short circuit.

[0242] Therefore, in the manufacturing process of the battery cell C, the current and temperature conditions that do not cause lithium precipitation are calculated and mapped, or manufacturing design and inspection are performed to prevent metal foreign matter from being mixed into the battery cell C. In the manufacturing process of the battery cell C, for example, whether lithium is precipitated is checked by irradiating light on the electrode surface of the battery cell C, or the resistance distribution on the surface of the negative electrode active material is measured to check the ease of lithium precipitation.

[0243] In the subsequent manufacturing process of the battery module BM, module assembly is performed to assemble the battery cells C and sensor assembly is performed to assemble the sensor unit 30 and the like to the assembled body of the battery cells C. In the manufacturing process of the battery module BM, the battery monitoring device 20 is mounted on the battery module BM. Thus, in the manufacturing stage of the battery module BM, the battery monitoring device 20 is capable of monitoring the amount of lithium deposition and the like.

[0244] In the next manufacturing process of the battery pack 1, pack assembly is performed in which the battery modules BM are assembled and housed in the sealed container 11. In this process, inspections such as conduction confirmation are appropriately performed.

[0245] In the next vehicle assembly process, the battery pack 1 is assembled to the vehicle and the vehicle is inspected. During the vehicle inspection, the continuity of the vehicle-mounted devices is checked, etc. After that, the vehicle equipped with the battery pack 1 is shipped from the factory to the user.

[0246] Alternatively, it is possible to disassemble the battery cell C to inspect the amount of lithium deposition, but this inspection method is difficult to implement on battery cells C that are actually used or on battery cells C that are in the manufacturing process, not to mention the development stage.

[0247] In this regard, Fig.24 As shown, the battery monitoring device 20 includes a deposition amount detection unit 37 for calculating the amount of lithium deposition using the output of a sensor provided in the battery module BM, and a storage unit 51 for storing the temporal change of the amount of lithium deposition as one of the battery usage histories.

[0248] The battery monitoring device 20 stores the amount of lithium deposition, etc., as one of the usage records when the user's vehicle is running, in the storage unit 51 as a storage medium. In addition, the battery monitoring device 20 stores the manufacturing process of the battery module BM, the manufacturing process of the battery pack 1, the amount of lithium deposition in the vehicle assembly process, etc., as one of the manufacturing records, in the storage unit 51 or an external storage device.

[0249] In addition, the battery monitoring device 20 includes an abnormality determination unit 544. When an abnormality occurs in the lithium-ion battery, the abnormality determination unit 544 determines the main cause of the abnormality of 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 determination unit 544 determines the time when the abnormality of the lithium-ion battery occurs by comparing the manufacturing history with the usage history as reference data, and determines the main cause of the abnormality of the lithium-ion battery by verifying the battery status before and after the occurrence time. The abnormality determination unit 544, for example, Fig.25 As shown, the timing when the amount of lithium deposition increases is identified as the time when abnormality of the lithium ion battery occurs.

[0250] The other parts are the same as those of the first embodiment. The battery monitoring device 20 of the present embodiment can obtain the effects achieved by the structure common to or equivalent to that of the first embodiment, as in the first embodiment.

[0251] Furthermore, the battery monitoring device 20 of the present embodiment has the following features.

[0252] (1) The battery monitoring device 20 includes a storage unit 51, which stores the temporal change of the amount of lithium precipitation as one of the usage history or manufacturing history of the lithium-ion battery. In this way, the lithium precipitation state can be checked by appropriately detecting the amount of lithium precipitation in a non-destructive manner and in a short time. In particular, a sensor for detecting lithium precipitation is provided to the battery module BM, so that the lithium precipitation state can be detected regardless of time and place. In addition, by storing the temporal change of the amount of lithium precipitation as one of the usage history or manufacturing history of the lithium-ion battery in the storage unit 51 in advance, it is possible to clearly understand when the lithium was precipitated. This has the advantage of being able to clearly identify the responsibility for lithium precipitation.

[0253] (2) In addition, the battery monitoring device 20 includes an abnormality determination unit 544, which determines the main cause of the abnormality of the lithium-ion battery based on the usage history and the manufacturing history of the lithium-ion battery when an abnormality occurs in the lithium-ion battery. If the main cause of the abnormality of the lithium-ion battery is determined based on the history information including not only the usage history but also the manufacturing history, it is possible to not only find the main cause of the abnormality at the usage stage but also trace it back to the manufacturing stage. This greatly contributes to clarifying the responsibility.

[0254] (Variation of the Second Embodiment)

[0255] The battery monitoring device 20 of the second embodiment may not be the same as the above-mentioned battery monitoring device, but may be partially different from the above-mentioned battery monitoring device. In addition, the technical matters described in the second embodiment can also be applied to devices and systems other than vehicle-mounted devices.

[0256] (Third Embodiment)

[0257] Next, regarding the third embodiment, refer to Figure 26 to Figure 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 is described.

[0258] like Fig.26 , Fig. 27 , Fig.28As shown, the large-capacity power storage system BSS includes a storage container SC, a plurality of battery modules BM, an air blowing device CM, a heater device HM, a battery management unit BMU, and the like.

[0259] The plurality of battery modules BM are storage batteries each including a lithium-ion battery. A sensor unit 30 is provided in each of the plurality of battery modules BM. The sensor unit 30 is configured similarly to the device described in the first embodiment.

[0260] The storage container SC is a container for storing a plurality of battery modules BM. The storage container SC is appropriately provided with openings for ensuring ventilation. The storage container SC is provided with a blower device CM and a heater device HM.

[0261] The air supply device CM is a cooling element of the battery module BM, and is used to generate airflow inside the storage container SC. The air supply device CM can be configured as a type of device that sucks air into the inside of the storage container SC, or as a type of device that presses air into the inside of the storage container SC. The air supply device CM is controlled to operate according to a control signal from the battery control device 140 described later.

[0262] The heater device HM is a heating element for the battery module BM, and is configured to include a heating element that generates heat by being energized. The heater device HM may be configured to heat the battery module BM directly or indirectly. The air supply device CM is controlled to operate according to a control signal from a battery control device 140 described later.

[0263] The battery management unit BMU manages the plurality of battery modules BM and includes a sensor unit 30 for monitoring the battery state including the amount of lithium deposition in the lithium-ion battery and a battery control device 140 for controlling the charging of the plurality of battery modules BM.

[0264] The battery control device 140 controls the charging of the plurality of battery modules BM based on the battery state monitored by the sensor unit 30. The battery control device 140 charges the plurality of battery modules BM using power obtained by solar power generation or power in a time period when electricity rates are low, for example.

[0265] Furthermore, a notification device ND is connected to the battery control device 140. The battery control device 140 notifies the outside of the battery state and the like monitored by the sensor unit 30 via the notification device ND.

[0266] Here, since the electrode potential of a lithium-ion battery drops to near the redox potential of lithium during charging, lithium is easily precipitated under conditions such as low-temperature charging, high-capacity charging, and overcharging. Lithium precipitation reduces the available lithium ions in the battery, causing a rapid decrease in battery capacity. In addition, if lithium precipitation continues, an internal short circuit is caused, and in the worst case, thermal runaway of the battery may develop.

[0267] In addition, once a battery fails, it may not be possible to store the energy generated before it is widely used, and there are cases where users and operators suffer great damage. Therefore, in order to continue to use the battery safely and securely, in addition to properly managing the temperature of the lithium-ion battery while charging and discharging, it is also required to detect signs of battery failure such as internal short circuits early to minimize downtime.

[0268] For example, consider Fig.29 As shown, when the temperature of the lithium ion battery becomes lower than a predetermined low temperature threshold, the battery temperature is increased by a heating element such as the heater device HM using the electric power stored in the battery as a power source.

[0269] However, the above method is a control method that focuses only on the battery temperature. Depending on the battery charge and discharge rate, it is not always necessary to raise the battery temperature. In addition, if only the battery temperature is focused on, the battery temperature will be excessively controlled, resulting in the possibility of excessive use of the power stored in the battery. In addition, in the case of large-scale storage equipment such as a large-capacity storage system BSS, the temperature distribution of the battery becomes complicated, making it difficult to properly grasp the battery temperature. In addition, it is difficult to detect battery failures such as internal short circuits at an early stage only through the temperature information of lithium-ion batteries. The system fails before the operator has time to secure appropriate maintenance hours, which may cause a lot of downtime. In addition, the charge and discharge rate is the speed of charging and discharging.

[0270] Considering these, the battery control device 140 heats the lithium-ion battery according to the amount of lithium precipitation during charge control. In addition, lithium precipitation may also occur outside of charge control. Therefore, it is desirable that the battery control device 140 is not limited to charge control, but heats the lithium-ion battery according to the amount of lithium precipitation.

[0271] The battery control device 140 is, for example, Fig.30 As shown in FIG. 1 , when the amount of lithium deposition increases beyond the first deposition threshold value Hi, the heater device HM starts to be energized to heat the battery module BM. The amount of lithium deposition decreases by heating the battery module BM. Furthermore, when the amount of lithium deposition falls below a second deposition threshold value Lo that is smaller than the first deposition threshold value Hi, the battery control device 140 stops energizing the heater device HM to stop heating the battery module BM.

[0272] Here, as described above, lithium deposition occurs not only during low-temperature charging but also during high-capacity charging or overcharging. In such conditions, the battery temperature of the battery module BM may rise to some extent.

[0273] Therefore, the battery control device 140 may also heat the lithium-ion battery according to the amount of lithium precipitation and the temperature of the battery module BM. Fig.31 As shown, when the amount of lithium deposition increases to exceed the first deposition threshold value Hi and the battery temperature of the battery module BM is equal to or lower than a predetermined low temperature threshold value, the heater device HM is energized to heat the battery module BM.

[0274] When the lithium deposition amount exceeds the first deposition threshold Hi while the battery temperature of the battery module BM exceeds the low temperature threshold, the battery control device 140 restricts the charge and discharge of the battery module BM or notifies the outside of the battery abnormality through the notification device ND.

[0275] Here, in order to suppress downtime, it is desirable to Fig.32 As shown, battery replacement is performed after the volumetric specific SOH of the battery decreases to a certain extent due to deterioration and before the amount of lithium deposition reaches an amount that causes an internal short circuit in the battery.

[0276] Taking this into consideration, the battery control device 140 of the present embodiment estimates the expected battery replacement period based on the change in the volume ratio SOH and the change in the lithium deposition amount output by the sensor unit 30, and notifies the battery replacement period to the outside as a recommended period through the notification device ND. Accordingly, operators and the like can know the recommended battery replacement period, thereby suppressing downtime caused by system failures including maintenance and battery failures.

[0277] The rest is the same as that of the first embodiment. The battery management unit BMU of this embodiment can obtain the effects achieved by the structure common to or equivalent to that of the first embodiment, as in the first embodiment.

[0278] In addition, the battery management unit BMU of this embodiment has the following features.

[0279] (1) When the amount of lithium deposition increases beyond a predetermined threshold, the battery module BM is heated by the heater device HM that raises the temperature of the battery module BM. Thus, the lithium-ion battery is heated at the time when the amount of lithium deposition increases, and the increase in the amount of lithium deposition is appropriately suppressed, so that the lithium-ion battery can be used in a safe and efficient manner. In particular, the battery management unit of this case is suitable for large-scale power storage devices where the temperature distribution is easily expanded.

[0280] (2) The sensor unit 30 includes a temperature sensor 31 for detecting the battery temperature of the lithium-ion battery. The battery control device 140 may heat the battery module BM by the heater device HM when the amount of lithium deposition increases beyond a predetermined threshold value and the battery temperature is below a predetermined low temperature threshold value. In this way, the lithium-ion battery can be used in a safe and efficient manner.

[0281] (Variation of the Third Embodiment)

[0282] In the third embodiment, the battery management unit BMU of the large-capacity power storage system BSS has been described in detail. However, the battery management unit BMU may not be the same as the above-mentioned battery management unit, but may be partially different from the above-mentioned battery management unit.

[0283] The technical matters described in the third embodiment can also be applied to devices and systems other than the large-capacity power storage system BSS. The battery management unit BMU can be applied to power supply management of a mobile object such as a vehicle, for example.

[0284] In the third embodiment, the heating element is constituted by the heater device HM, but the present invention is not limited thereto and the heating element may be constituted by a load device located around the battery. In addition, the heating element may be heated by power supplied from outside the battery module BM.

[0285] Here, the amount of lithium precipitation has the following trend: if the battery temperature is low and the charging rate is high, the amount of lithium precipitation increases, and if the battery temperature is high and the charging rate is low, the amount of lithium precipitation decreases. In this way, there is a certain correlation between the amount of lithium precipitation and the charging rate and the battery temperature. Therefore, the precipitation amount detection unit 37 can also refer to, for example, Fig.33 The amount of lithium deposition is calculated using a control map that defines the correlation between the amount of lithium deposition, the charging rate, and the battery temperature as shown in the figure. This also applies to embodiments other than this embodiment.

[0286] (Fourth Embodiment)

[0287] Next, regarding the fourth embodiment, refer to Fig.34 , Fig.35 In this embodiment, a battery transport device BSC that stores batteries in a storage container SC and transports the batteries will be described.

[0288] Lithium-ion batteries also contain toxic and flammable chemicals, so they need to be transported safely. For example, regarding transportation by aircraft, international regulations stipulate packaging standards based on the lithium content. Battery packs used in electric vehicles have a high lithium content, which makes it difficult to transport them by aircraft due to regulations. They are generally transported by sea by ship. Compared with air transport, sea transport requires long-term transportation. For example, in summer, it becomes a long-term transportation under high temperature / high humidity conditions, and in winter, it becomes a long-term transportation under low temperature conditions. Under such a stress environment, once the lithium-ion battery is transferred to an unsafe state, the lithium-ion battery becomes difficult to control and may cause damage to other cargo and passengers, so it is important to monitor the safety status of the lithium-ion battery.

[0289] In this regard, it is conceivable to transport the lithium ion battery using a transport container formed of a non-combustible material and having a cooling mechanism, and inactivate the lithium ion battery by the cooling mechanism when a battery unsafe event is detected using the gas sensor 35 .

[0290] However, the chemical reaction that causes the lithium-ion battery to reach an unsafe state is a chain reaction of exothermic reactions. When the gas sensor 35 is used to detect an unsafe event of the battery as in the above method, the chain reaction has already begun at the time when the gas is ejected 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 ejected gas is harmful, so it may cause damage to the loaded cargo and passengers.

[0291] Taking this into consideration, the battery transport equipment BSC of this embodiment is configured to monitor factors of abnormal heating phenomenon that causes the battery temperature to continue to rise unintentionally, and detect abnormal conditions occurring in the battery at the initial stage of the abnormal heating phenomenon based on the monitoring results.

[0292] like Fig.34 As shown, the battery transport equipment BSC includes a storage container SC for storing a plurality of battery modules BM, a sensor unit 30A for detecting the battery states of the plurality of battery modules BM, and an abnormality detection unit 150 .

[0293] like Fig.35 As shown, 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 precipitation amount detection unit 37 described in the first embodiment. The humidity sensor HS is provided inside the storage container SC to detect the humidity inside the storage container SC. The acceleration sensor GS is provided in the storage container SC to detect vibration and impact applied to the storage container SC. In addition, the sensor unit 30A may also include other sensors.

[0294] The sensor unit 30A of the present embodiment includes a wireless communication device (not shown) for wirelessly communicating with the abnormality detection unit 150. Alternatively, the sensor unit 30A may include a communication device for wirelessly communicating with the abnormality detection unit 150 via wire.

[0295] The abnormality detection unit 150 suppresses the occurrence of abnormal heating phenomenon based on the monitoring result of the factors causing the abnormal heating phenomenon, detects the abnormal state generated in the battery at the initial stage of the occurrence of the abnormal heating phenomenon, and implements countermeasures against the abnormal heating 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 storage unit 51, a wireless communication unit 52, an internal resistance detection unit 53, a monitoring IC 54, etc.

[0296] The abnormality detection unit 150 performs the operation described in the first embodiment to prevent abnormal heating and detect it at an early stage. Fig.12 In addition, the abnormality detection unit 150 implements the external notification process and the battery protection process described in the first embodiment as a countermeasure against the abnormal heating phenomenon.

[0297] In the external notification process, a signal indicating the occurrence of abnormal heating phenomenon is output to the notification device ND, and the occurrence of abnormal heating phenomenon is notified to the outside through the notification device ND. In the external notification process, it is desirable to notify the outside of at least one of the sensor output of the temperature sensor 31, the humidity sensor HS, and the acceleration sensor GS, and the position information of the battery module BM where the abnormal heating phenomenon has occurred. The reason for this is that it is easy to identify the responsibility related to the occurrence of the abnormal heating phenomenon. In addition, regarding the position information of the battery module BM, for example, information determined based on the radio wave strength of the signal emitted by the sensor unit 30A can be used.

[0298] The other parts are the same as those of the first embodiment. The battery transport equipment BSC of this embodiment can obtain the effects achieved by the common or equivalent structure to that of the first embodiment, as in the first embodiment.

[0299] Furthermore, the battery transport equipment BSC of the present embodiment has the following features.

[0300] (1) The battery transport equipment BSC includes: a storage container SC; a factor monitoring unit that monitors factors causing abnormal heating phenomena that cause the temperature of the battery to continue to rise unintentionally; and an abnormality detection unit 150 that detects abnormalities in the battery. In addition, the abnormality detection unit 150 suppresses the occurrence of abnormal heating phenomena based on the monitoring results of the factor monitoring unit, detects abnormal conditions generated in the battery at the initial stage of the occurrence of the abnormal heating phenomenon, and implements countermeasures against the abnormal heating phenomenon based on the detection results of the abnormal conditions. Accordingly, when transporting batteries, the occurrence of abnormal heating phenomena can be prevented in advance, and even if abnormal heating phenomena occur, effective thermal countermeasures such as implementing countermeasures from the initial stage of its occurrence can be implemented.

[0301] (Variation of the Fourth Embodiment)

[0302] In the fourth embodiment, the battery transport equipment BSC is described in detail, but the battery transport equipment BSC may not be the same as the above-mentioned battery transport equipment, and a part of it may be different from the above-mentioned battery transport equipment. In addition, the technical matters described in the fourth embodiment can also be applied to equipment and systems other than the battery transport equipment BSC.

[0303] (Other embodiments)

[0304] As mentioned above, although the typical embodiment of this disclosure was described, this disclosure is not limited to the above-mentioned embodiment, For example, various modifications are possible as follows.

[0305] The charging system BCS and the charger 120 described above must make a determination on whether or not the charging of the stored electricity is possible based on the battery information and control the charging and discharging based on the result of the determination, but measures for abnormal heating of the battery, etc., are not necessary. In addition, the battery information only needs to include information related to the amount of lithium deposition, and may not include the volume ratio SOH, etc.

[0306] The above-described charging system BCS and charger 120 are configured to charge the battery by the CCCV charging method, but may be configured to charge the battery by other charging methods.

[0307] The above-described charging system BCS and charger 120 are configured to charge the battery by the CCCV charging method, but may be configured to charge the battery by other charging methods.

[0308] In the above-mentioned embodiment, the updating method of the target current amount during charging is described in detail, but the updating method of the target current amount may also be different from the above-mentioned method. The charger 120 may, for example, maintain the target current amount constant when lithium precipitation is detected. In addition, the charger 120 may, for example, change the target current amount stepwise or continuously according to the lithium precipitation amount.

[0309] Although it is preferred that the charger 120 estimates the required charging time required for charging based on the battery state and notifies the information indicating the estimated required charging time to the outside through the notification device ND, this may not be the case. In addition, although it is preferred that the charger 120 notifies the information indicating the amount of lithium deposition to the outside through the notification device ND, this may not be the case.

[0310] The application of the charging system BCS and the charger 120 described above is not limited to the vehicle-mounted battery mounted on the vehicle. The charging system BCS and the charger 120 can also be applied to charging a fixed type battery or a portable battery, for example.

[0311] The battery monitoring device 20 described above includes the flexible printed circuit board FPC and the ASIC circuit, but is not limited thereto. The flexible printed circuit board FPC and the ASIC circuit are not essential components of the battery monitoring device 20.

[0312] As in the above-described embodiment, the battery monitoring device 20 desirably corrects the estimated value of the lithium deposition amount using the battery temperature or the parasitic resistance value, but this does not necessarily have to be the case.

[0313] As in the above-described embodiment, the battery monitoring device 20 desirably compares a predetermined battery state estimated from the lithium deposition amount with a predetermined battery state estimated from other factors to diagnose the suitability of the deposition amount detection unit 37 , but this does not necessarily have to be the case.

[0314] In the above embodiment, the volume fraction SOH is estimated based on the amount of lithium precipitation and the thickness of the SEI layer of the battery, but the volume fraction SOH may be estimated based on other physical quantities. The battery monitoring device 20 may also detect a degradation state including a rupture of the positive electrode of the battery, for example, and calculate the volume fraction SOH based on the degradation state.

[0315] As in the above-mentioned embodiment, it is desirable that the battery monitoring device 20 and the battery management device 60 together constitute a battery management system BMS for managing the battery module BM, but this is not necessarily the case. This also applies to the charging system BCS and the battery evaluation system BRS. In addition, the battery evaluation system BRS may also be configured as a functional unit in the battery management system BMS.

[0316] The monitoring target of the battery monitoring device 20 is not limited to the vehicle-mounted battery mounted on the vehicle. The battery monitoring device 20 can also be used as a device for monitoring a fixed type storage battery or a portable storage battery, for example.

[0317] The battery monitoring device 20 basically monitors lithium-ion batteries, but is not limited thereto. If the same problem as that of lithium-ion batteries may occur, such batteries can also be monitored. In addition, the battery that becomes the monitoring object of the battery monitoring device 20 does not have to be a battery formed by modularizing multiple battery cells C.

[0318] The battery monitoring device 20 may be connected to the battery ECU 100 by wire instead of by wireless. The battery monitoring device 20 is not limited to a device that is completely identical to the above-mentioned device, and may be partially different from the above-mentioned device.

[0319] In the above-described embodiment, the elements constituting the embodiment are of course not essential elements unless they are specifically stated to be essential or unless they are obviously essential in principle.

[0320] In the above-mentioned embodiments, when quantitative values ​​such as the number, numerical value, amount, range, etc. of the structural elements of the embodiments are mentioned, they are not limited to the specific number except for the cases where they are specifically stated to be required and the cases where they are obviously limited to a specific number in principle.

[0321] In the above-mentioned embodiments, when the shapes, positional relationships, etc. of components are mentioned, they are not limited to the shapes, positional relationships, etc. unless otherwise specified or when they are limited to specific shapes, positional relationships, etc. in principle.

[0322] The control unit and method of the present disclosure may also be implemented by a special-purpose computer provided by a processor and a memory programmed to perform one or more functions embodied by a computer program. The control unit and method of the present disclosure may also be implemented by a special-purpose computer provided by a processor composed of one or more special-purpose hardware logic circuits. The control unit and method of the present disclosure may also be implemented by one or more special-purpose computers composed of a combination of a processor and a memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. In addition, the computer program may also be stored in a computer-readable non-transitory tangible recording medium as an instruction executed by a computer.

[0323] [Features of the present disclosure]

[0324] The present disclosure has the following viewpoints.

[0325] [First point of view]

[0326] A battery charging system (BCS) comprising:

[0327] a charger (120) for a secondary battery (BM) comprising lithium-ion cells; and

[0328] A battery-side device (20, 100) monitors the battery state including the amount of lithium deposition in the lithium-ion battery.

[0329] The charger comprises:

[0330] An information acquisition unit (121) acquires battery information including the battery status from the battery-side device;

[0331] A charging determination unit (122) determines whether the storage battery can be charged based on the battery information; and

[0332] A charging control unit (123) charges the storage battery based on the determination result of the charging determination unit.

[0333] [Second point of view]

[0334] According to the charging system described in the first viewpoint, the charging control unit is configured to charge the battery by a CCCV charging method in which charging is performed at a constant voltage after charging at a constant current, and if the amount of lithium deposition increases by more than a prescribed threshold value during charging at the constant current, the current amount of the constant current is reduced.

[0335] [Third point of view]

[0336] According to the charging system described in the second aspect, the battery-side device,

[0337] When charging of the storage battery is started by the charging control unit, it is periodically determined whether the amount of lithium deposition increases to exceed the threshold value.

[0338] If the lithium deposition amount increases beyond the threshold value, the target current amount during the constant current charging is set to a value smaller than the current current amount, and the target current amount is notified to the charger,

[0339] The charging control unit adjusts the current amount of the constant current based on the target current amount when the target current amount is obtained from the battery-side device during the charging at the constant current.

[0340] [Fourth point of view]

[0341] According to the charging system described in any one of the eleventh to third aspects, the charger estimates a required charging time required for the charging based on the battery state, and notifies information indicating the estimated required charging time to the outside via a notification device (ND).

[0342] [Fifth Viewpoint]

[0343] According to the charging system described in any one of the first to fourth aspects, the charger notifies the outside of the information indicating the amount of lithium deposition via a notification device (ND).

[0344] [Sixth Viewpoint]

[0345] A charger, which is a charger for a secondary battery (BM) including a lithium-ion battery, comprising:

[0346] An information acquisition unit (121) acquires battery information including the battery status from a battery-side device (20, 100) that monitors the battery status including the amount of lithium deposition in the lithium-ion battery;

[0347] A charging determination unit (122) determines whether the storage battery can be charged based on the battery information; and

[0348] A charging control unit (123) charges the storage battery based on the determination result of the charging determination unit.

Claims

1. A battery charging system (BCS), comprising: a charger (120) for a secondary battery (BM) comprising lithium-ion cells; and A battery-side device (20, 100) monitors the battery state including the amount of lithium deposition in the lithium-ion battery. The charger comprises: An information acquisition unit (121) acquires battery information including the battery status from the battery-side device; A charging determination unit (122) determines whether the storage battery can be charged based on the battery information; and A charging control unit (123) charges the storage battery based on the determination result of the charging determination unit.

2. The charging system according to claim 1, characterized in that: The charging control unit is configured to charge the battery by a constant current constant voltage charging method, i.e., CCCV charging method, in which charging is performed at a constant current followed by charging at a constant voltage. If the amount of lithium deposition increases by more than a predetermined threshold value during charging at the constant current, the current amount of the constant current is reduced.

3. The charging system according to claim 2, characterized in that: The battery side device, When charging of the storage battery is started by the charging control unit, it is periodically determined whether the amount of lithium deposition increases to exceed the threshold value. If the lithium deposition amount increases beyond the threshold value, the target current amount during the constant current charging is set to a value smaller than the current current amount, and the target current amount is notified to the charger, The charging control unit adjusts the current amount of the constant current based on the target current amount when the target current amount is obtained from the battery-side device during the charging at the constant current.

4. The charging system according to any one of claims 1 to 3, characterized in that: The charger estimates a required charging time required for the charging based on the battery state, and notifies information indicating the estimated required charging time to the outside through a notification device (ND).

5. The charging system according to any one of claims 1 to 3, characterized in that: The charger notifies information indicating the amount of lithium deposition to the outside via a notification device (ND).

6. A charger for a secondary battery (BM) including a lithium-ion battery, comprising: An information acquisition unit (121) acquires battery information including the battery status from a battery-side device (20, 100) that monitors the battery status including the amount of lithium deposition in the lithium-ion battery; A charging determination unit (122) determines whether the storage battery can be charged based on the battery information; and A charging control unit (123) charges the storage battery based on the determination result of the charging determination unit.

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