Battery Capacity Recovery System

Abstract

To properly recover a secondary battery in a battery capacity recovery system.SOLUTION: A battery capacity recovery system 100 includes a battery system 56 including a second battery having a plurality of battery cells connected in series and a battery control device for controlling the plurality of battery cells, a charger 54 for charging the battery system 56, a processor 70 connected to a database part 80 for storing information on the battery system 56, and a communication device 52 connected to the battery system 56 or the charger 54 to input and output information to / from the processor 70. The processor 70 includes a data acquisition part 71 for acquiring an operation history, and a recovery capacity calculation part 72 for calculating a recovery capacity expectation value being an expectation value at which capacity can be recovered in the secondary battery 20 on the basis of the operation history.SELECTED DRAWING: Figure 3A

Description

[Technical field]

[0001] The present invention relates to a battery capacity recovery system. [Background technology]

[0002] As background art in this technical field, the abstract of the following Patent Document 1 states, "A capacity recovery system recovers the capacity of a battery pack of lithium ion secondary batteries mounted on a vehicle. The capacity recovery system includes a capacity recovery device 40, a communication device 340, and a server 300. The capacity recovery device 40 is configured to be able to execute a recovery process that recovers the capacity of the battery pack 10 by maintaining the SOC of the battery pack 10 below a reference value X2. The communication device 340 acquires recovery data P1, P2 including the SOC reference value X2 used in the recovery process and the capacity recovery rate R by the recovery process. The server 300 calculates the reference value X2 used in the recovery process for vehicle 1, which is a target vehicle, using the recovery data P1, P2." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-63906 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned technology, there is a demand for a method for more appropriately restoring the capacity of a secondary battery. The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a battery capacity recovery system that can appropriately recover the capacity of a secondary battery. [Means for solving the problem]

[0005] In order to solve the above problem, the battery capacity recovery system of the present invention comprises a battery system including a secondary battery having a plurality of battery cells connected in series and a battery control device controlling the plurality of battery cells, a charger for charging the battery system, a processing device connected to a database unit for storing information related to the battery system, and a communication device connected to the battery system or the charger and for inputting and outputting information between the battery system and the charger, wherein the processing device comprises: a data acquisition unit that acquires, from the communication device when the battery system and the charger are connected, an operation history including time series data of the cell voltage of the battery cell and time series data of the cell current which is the current flowing through the battery cell, based on the operation history; a recovery capacity calculation unit that calculates a recovery capacity expectation value which is an expected value for which capacity can be restored in the secondary battery based on the recovery capacity expectation value; a capacity recovery control unit that outputs a capacity recovery command to the secondary battery via the communication device to perform a capacity recovery process; and an alarm unit that transmits, to a specified terminal device, whether the capacity recovery process is being executed or not, or a schedule for the capacity recovery process. Effect of the Invention

[0006] According to the present invention, the capacity of a secondary battery can be appropriately restored. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a schematic cross-sectional view of a bipolar battery cell. [Diagram 2] FIG. 2 is a schematic side view of the electricity storage element. [Figure 3A] 1 is a block diagram of a battery capacity recovery system according to a first embodiment. [Figure 3B] FIG. 1 is a block diagram of a computer. [Figure 4] FIG. 2 is a block diagram of a battery pack. [Diagram 5] FIG. 1 is a diagram showing an overview of a material property database. [Figure 6] FIG. 2 is a diagram showing an overview of a deterioration prediction database. [Figure 7]FIG. 13 is a diagram showing an overview of a capacity recovery database. [Figure 8] FIG. 2 is a diagram showing an overview of a safety judgment database. [Figure 9] 13 is a flowchart of a diagnostic mode processing routine. [Figure 10] FIG. 4 is a diagram showing an example of potential curve data. [Figure 11] FIG. 4 is an enlarged view of a main portion of negative electrode potential curve data. [Figure 12] 2 is a block diagram showing the relationship between the main parts of a server machine and a database unit. [Figure 13] 4 is a flowchart (1 / 2) of a capacity recovery processing routine in the first embodiment. [Figure 14] 13 is a flowchart (2 / 2) of a capacity recovery processing routine in the first embodiment. [Figure 15] FIG. 11 is a diagram showing an example of a distribution state of discharge amount data during a capacity recovery process. [Figure 16] FIG. 13 is a diagram illustrating an example of a distribution state of recovery upper limit capacity data. [Figure 17] FIG. 5 is a block diagram of a battery capacity recovery system according to a second embodiment. [Figure 18] 10 is a flowchart of a diagnosis process in the second embodiment. [Figure 19] 13 is a flowchart of a capacity recovery processing routine in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Battery cell structure] First, with reference to Figs. 1 and 2, a structural example of a bipolar battery cell applicable to the embodiment will be described. FIG. 1 is a schematic cross-sectional view of a bipolar battery cell 10. In Fig. 1, a battery cell 10 is a lithium-ion battery cell, and includes an electricity storage element 1, a positive electrode terminal 2, a negative electrode terminal 3, and an exterior material 6. A separator 5 is included in the electricity storage element 1. The exterior material 6 is made of a laminate film or a similar material. The shape of the battery cell 10 is not limited to a rectangular shape as shown in Fig. 1, and may be a cylindrical shape (not shown).

[0009] FIG. 2 is a schematic side view of the electricity storage element 1. As shown in FIG. As shown in FIG. 2, in the electric storage element 1, a plurality of positive electrodes 12 and a plurality of negative electrodes 13 are alternately stacked with a separator 5 interposed therebetween. The electric storage element 1 shown in FIG. 1 corresponds to the area where the positive electrodes 12 and the negative electrodes 13 appear to overlap. The structure of the electric storage element 1 is not limited to the stacked type as shown in FIG. 2. That is, although not shown, the electric storage element 1 may be a wound type fabricated by stacking the positive electrodes 12 and the negative electrodes 13 so as to face each other with the separator 5 therebetween and then winding the stack. The electric storage element 1 further contains an electrolyte (not shown), and the electrolyte is impregnated into the micropores of the positive electrodes 12, the negative electrodes 13, the separator 5, and the like. For example, polypropylene can be used as the separator 5. However, in addition to polypropylene, a microporous film or nonwoven fabric made of polyolefin such as polyethylene can also be used as the separator 5.

[0010] The positive electrode 12 and the negative electrode 13 are each made by applying a mixture of an appropriate electrode active material, a conductive agent, a binder, etc., to a current collector foil of an appropriate metal. Metal tabs are connected to the current collector foils of the positive electrode 12 and the negative electrode 13. The exterior material 6 is sealed so that only the tabs are exposed to the outside of the exterior material 6. As a result, the tabs become the positive electrode terminal 2 and the negative electrode terminal 3 in FIG. 1. Hereinafter, the potentials of the positive electrode 12 and the negative electrode 13 are referred to as the positive electrode potential Ep and the negative electrode potential En. The difference between the two, i.e., "Ep-En", is the voltage between the positive electrode terminal 2 and the negative electrode terminal 3, and this is referred to as the cell voltage V.

[0011] The current collector foil of the positive electrode 12 may be made of aluminum foil having a thickness of 10 to 100 μm, aluminum perforated foil having a thickness of 10 to 100 μm and a pore size of 0.1 to 10 mm, expanded metal, foam metal plate, or the like. In addition to aluminum, stainless steel, titanium, or the like may also be used as the material of the current collector foil. In this embodiment, any current collector can be used without being limited by the material, shape, manufacturing method, or the like.

[0012] The electrode active material of the positive electrode 12 preferably contains a reactive species therein. The reactive species of a lithium ion battery is lithium ions. In this case, the electrode active material of the positive electrode 12 contains a lithium-containing compound capable of reversibly inserting and detaching lithium ions. The type of electrode active material of the positive electrode 12 is not particularly limited, and examples thereof include lithium transition metal phosphates such as lithium cobalt oxide, lithium manganese-substituted cobalt oxide, lithium manganate, lithium nickel oxide, and olivine-type lithium iron phosphate; Li w Ni x Co y Mn z O2 (wherein w, x, y, and z are 0 or positive values). The electrode active material of the positive electrode 12 may contain one or more of the above materials.

[0013] The current collector foil of the negative electrode 13 may be a copper foil having a thickness of 10 to 100 μm, a perforated copper foil having a thickness of 10 to 100 μm and a pore size of 0.1 to 10 mm, an expanded metal, a foamed metal plate, or the like. The material of the current collector foil may be, other than copper, stainless steel, titanium, or the like. In this embodiment, any current collector may be used without being limited by the material, shape, manufacturing method, or the like.

[0014] The electrode active material of the negative electrode 13 includes a material capable of reversibly inserting and detaching lithium ions. The type of electrode active material of the negative electrode 13 is not particularly limited, but may be, for example, natural graphite, a composite carbonaceous material in which a coating is formed on natural graphite by a dry CVD method or a wet spray method, artificial graphite produced by firing a resin material such as epoxy or phenol or a pitch-based material obtained from petroleum or coal, silicon (Si), graphite mixed with silicon, a non-graphitizable carbon material, lithium titanate Li4Ti5O 12 , niobium titanium oxide TiNb2O7, etc. The negative electrode active material may contain one or more of the above materials.

[0015] An electrolyte is impregnated in the electricity storage element 1. The electrolyte is not particularly limited, but in the case of a lithium ion battery, for example, an aprotic organic solvent such as ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), methyl propyl carbonate (MPC), or ethyl propyl carbonate (EPC) can be used.

[0016] The electrolyte may also be prepared by dissolving a lithium salt such as lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium iodide, lithium chloride, lithium bromide, LiB[OCOCF3]4, LiB[OCOCF2CF3]4, LiPF4(CF3)2, LiN(SO2CF3)2, LiN(SO2CF2CF3)2, or a mixed lithium salt of two or more of these in a solvent of a mixed organic compound of two or more of these.

[0017] A solid electrolyte may be used instead of the electrolytic solution. The solid electrolyte is not particularly limited, but examples thereof include ion-conductive polymers such as polyethylene oxide, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, polyhexafluoropropylene, and polyethylene oxide. When such a solid polymer electrolyte is used, the separator 5 can be omitted.

[0018] [First embodiment] Configuration of the First Embodiment FIG. 3A is a block diagram of a battery capacity recovery system 100 according to a first embodiment. The battery capacity recovery system 100 includes a communication module 52 (communication device), a charger 54, a battery system 56, a user terminal 60 (terminal device), a server machine 70 (processing device), and a database unit 80.

[0019] The user terminal 60 is, for example, a portable information terminal. The server machine 70 includes a data acquisition unit 71, a recovery upper limit capacity calculation unit 72 (recovery capacity calculation unit), a recoverable capacity calculation unit 74, an operation history / deterioration rate validity determination unit 75, a capacity recovery control unit 76, a notification unit 77, a capacity recovery evaluation unit 78, and a capacity recovery amount prediction correction unit 79.

[0020] The database unit 80 includes a material property database 82, a deterioration prediction database 84, a capacity recovery database 86, and a safety determination database 88 (relationship storage database). The database unit 80 in this embodiment does not simply store data, but also has a function of outputting predicted values ​​for data that has not been stored by executing machine learning, interpolation processing, and the like.

[0021] When the battery system 56 and the charger 54 are connected, the data acquisition unit 71 in the server machine 70 acquires operation history data including time series data of the cell voltage V and cell current I of each battery cell 10 from the communication module 52. Furthermore, the recovery upper limit capacity calculation unit 72 calculates recovery upper limit capacity expectation value data, which is an expectation value for which capacity can be restored in the battery pack 20 (secondary battery, see FIG. 4), based on the operation history data.

[0022] The function of the recoverable capacity calculation unit 74 will be described later. The operation history / deterioration rate validity determination unit 75 determines whether or not the operation history data Dn11 and deterioration rate data Dn12 of the target battery pack 20 have a predetermined validity. The capacity recovery control unit 76 outputs a capacity recovery command to the battery pack 20 via the communication module 52 based on the recovery upper limit capacity expectation value data, to instruct the battery pack 20 to execute a capacity recovery process (S22, S24 described later).

[0023] The notification unit 77 transmits information on whether or not the capacity recovery process (S22, S24 described later) is being executed, or a schedule for the capacity recovery process (S22, S24), to the user terminal 60. Furthermore, the notification unit 77 notifies the user terminal 60 of the recovery upper limit capacity expected value data, the capacity recovery actual value, and the next capacity recovery time.

[0024] The capacity recovery evaluation unit 78 determines whether the capacity recovery process (S22, S24) was successful or not based on the contents of the safety judgment database 88, the discharge amount data after executing the capacity recovery process (S22, S24), and the capacity recovery performance value data.

[0025] Fig. 3B is a block diagram of a computer 980. Each of the server machine 70, the charger 54, the user terminal 60 and the database unit 80 shown in Fig. 3A includes one or more computers 980 shown in Fig. 3B. 3B, a computer 980 includes a CPU 981, a storage unit 982, a communication I / F (interface) 983, an input / output I / F 984, and a media I / F 985. Here, the storage unit 982 includes a RAM 982a, a ROM 982b, and an HDD 982c.

[0026] The communication I / F 983 is connected to a communication circuit 986. The input / output I / F 984 is connected to an input / output device 987. The media I / F 985 reads and writes data from a recording medium 988. The ROM 982b stores control programs executed by the CPU, various data, etc. The CPU 981 executes application programs loaded into the RAM 982a to realize various functions. The interior of the server machine 70 shown in FIG. 3A above shows functions realized by application programs, etc., as blocks.

[0027] Fig. 4 is a block diagram of the battery pack 20. The battery system 56 shown in Fig. 3A includes this battery pack 20. In FIG. 4, the battery pack 20 includes a plurality of battery cells 10 connected in series, a plurality of cell controllers 22, a plurality of voltage detection lines 23, a plurality of thermocouples 24, a battery control device 25, communication lines 26, 28, and a current sensor 27.

[0028] The cell controller 22 is connected to the battery cells 10 via a voltage detection line 23, and detects the states of these battery cells 10, i.e., the cell voltage V (see FIG. 1) and temperature. The multiple cell controllers 22 are also connected to a battery control device 25 via a communication line 26. A current sensor 27 detects a cell current I flowing through the series-connected battery cells 10, and notifies the battery control device 25 of the cell current I. The battery control device 25 obtains the states of the multiple battery cells 10 from the multiple cell controllers 22.

[0029] The battery control device 25 calculates the SOC (state of charge) of the battery pack 20 and other data based on the cell current I obtained from the current sensor 27 and the states of the multiple battery cells 10 obtained from the cell controller 22. The battery control device 25 then communicates the calculated SOC and other data to a higher-level device (for example, the charger 54 or server machine 70 in FIG. 3A) via the communication line 28.

[0030] FIG. 5 is a diagram showing an overview of the material property database 82. As shown in FIG. 5, the material property database 82 stores deterioration state data D10 and potential curve data D50 in association with each other. Here, the deterioration state data D10 includes operation history data D11 (operation history) and deterioration rate data D12 (deterioration rate).

[0031] The operation history data D11 is time-series data of the SOC, temperature, cell voltage V, cell current I, voltage drop rate, etc. of each battery cell 10. The deterioration rate data D12 includes a capacity deterioration rate SOHQ of the battery pack 20, a resistance deterioration rate SOHR of the battery pack 20, a capacity deterioration rate SOHQ of each battery cell 10, and a resistance deterioration rate SOHR of each battery cell 10.

[0032] The potential curve data D50 also includes positive electrode potential curve data D54 and negative electrode potential curve data D56. Here, the positive electrode potential curve data D54 indicates the characteristics of the positive electrode potential Ep (see FIG. 1) relative to the discharge amount or charge amount of the battery cell 10. Moreover, the negative electrode potential curve data D56 indicates the characteristics of the negative electrode potential En (see FIG. 1) relative to the discharge amount or charge amount of the battery cell 10.

[0033] FIG. 6 is a diagram showing an overview of the deterioration prediction database 84. As shown in FIG. 6, the deterioration prediction database 84 stores the above-mentioned operation history data D11 and the above-mentioned deterioration rate data D12 in association with each other for various battery packs 20 (see FIG. 4).

[0034] FIG. 7 is a diagram showing an overview of the capacity recovery database 86. As shown in FIG. 7, the capacity recovery database 86 stores, in association with each other, degradation state data D10, recovery upper limit capacity data D20, and capacity recovery performance value data D24. Here, the recovery upper limit capacity data D20 is data indicating the upper limit of the capacity that can be recovered by the capacity recovery process in the battery pack 20 (see FIG. 4).

[0035] The capacity recovery rate data D22 is a result of dividing the capacity recovery result value data D24 by the recovery upper limit capacity data D20. Here, the capacity recovery result value data D24 is data indicating the result value of the capacity recovered by the capacity recovery process. The capacity recovery database 86 also does not include data in the case where the determination result in the capacity recovery evaluation unit 78 described above is negative, that is, where the capacity recovery process has failed.

[0036] FIG. 8 is a diagram showing an overview of the safety determination database 88. As shown in FIG. 8, the safety determination database 88 stores discharge amount data D30, capacity recovery result value data D24, and safety determination data D32 in association with each other. Here, the discharge amount data D30 is data indicating the discharge amount in the capacity recovery process.

[0037] The safety determination data D32 is data indicating the degree of safety when the capacity recovery process is executed under the conditions for the corresponding discharge amount data D30 and capacity recovery result value data D24. The safety determination database 88 also does not include data when the determination result in the capacity recovery evaluation unit 78 is negative, that is, when the capacity recovery process fails.

[0038] Operation of the First Embodiment Next, the operation of this embodiment will be described. FIG. 9 is a flowchart of the diagnostic mode processing routine. This routine is started when a command to execute a diagnostic mode process is output from the user terminal 60 (see FIG. 3A). First, when the process proceeds to step S2 in the charger 54, the charger 54 executes a charging process. The charging process in step S2 is an intermittent charging process or a charging process at a low current. In other words, it is preferable that the charging process includes a timing at which the cell voltage V is considered to be equal to OCV (Open Circuit Voltage).

[0039] Next, when the process proceeds to step S4 in the charger 54, the charger 54 transmits the operation history data Dn11 obtained in the previous step S2 to the server machine 70. Here, the operation history data Dn11 includes data such as the cell current I (see FIG. 5), the cell voltage V (see FIG. 1), the voltage drop rate, and the temperature, similar to the operation history data D11 (see FIG. 6). However, the operation history data Dn11 was obtained in the previous step S2, and is generally not yet included in the deterioration prediction database 84.

[0040] Meanwhile, in step S8, the server machine 70 receives the operation history data Dn11 from the charger 54. Next, when the process in the server machine 70 proceeds to step S10, the recovery upper limit capacity calculation unit 72 of the server machine 70 refers to the material property database 82 and the deterioration prediction database 84. That is, the recovery upper limit capacity calculation unit 72 reads out, from the deterioration prediction database 84, the operation history data D11 adjacent to the operation history data Dn11 currently acquired from the charger 54 and the corresponding deterioration rate data D12.

[0041] Then, the recovery upper limit capacity calculation unit 72 performs an interpolation process on the read data to calculate deterioration rate data Dn12 (not shown) corresponding to the current operation history data Dn11. This results in deterioration state data Dn10 (not shown) that combines the operation history data Dn11 and the deterioration rate data Dn12. Next, the recovery upper limit capacity calculation unit 72 refers to the material property database 82 and acquires potential curve data Dn50 corresponding to the deterioration state data Dn10.

[0042] First, FIG. 10 is a diagram showing an example of the potential curve data Dn50. In Fig. 10, the potential curve data Dn50 includes corrected positive electrode potential curve data Dn54 and corrected negative electrode potential curve data Dn56 (negative electrode potential curve data). The voltage curve data Vx in the figure is the result of subtracting the corrected negative electrode potential curve data Dn56 from the corrected positive electrode potential curve data Dn54. The vertical axis in Fig. 10 represents voltage and potential. The horizontal axis represents discharge capacity [Ah], with a value of "0" representing a fully charged state and a negative value representing an overcharged state.

[0043] The recovery upper limit capacity calculation unit 72 acquires the potential curve data Dn50 as follows. First, the material property database 82 stores the positive electrode potential curve data D54 and the negative electrode potential curve data D56. These have shapes that are similar to the corrected positive electrode potential curve data Dn54 and the corrected negative electrode potential curve data Dn56 shown in Fig. 10. Also, the difference between the positive electrode potential curve data D54 and the negative electrode potential curve data D56 provides a virtual characteristic of the cell voltage V (see Fig. 1).

[0044] This hypothetical characteristic has a shape similar to the voltage curve data Vx shown in Fig. 10, but generally deviates from the voltage curve data Vx. Therefore, the recovery upper limit capacity calculation unit 72 shifts and expands the positive electrode potential curve data D54 and the negative electrode potential curve data D56 in the horizontal axis direction to obtain the shift amount and expansion / contraction rate at which the hypothetical characteristic of the cell voltage V (see Fig. 1) most closely resembles the voltage curve data Vx.

[0045] Then, the positive electrode potential curve data D54 and the negative electrode potential curve data D56 are modified based on the determined shift amount and expansion / contraction rate to become the corrected positive electrode potential curve data Dn54 and the corrected negative electrode potential curve data Dn56 shown in FIG.

[0046] 9, when the process proceeds to step S12, the recovery upper limit capacity calculation unit 72 calculates the recovery upper limit capacity expectation value data Dn20 based on the potential curve data Dn50. Details of the process in step S12 will be described with reference to FIGS. 10 and 11 again.

[0047] 10, the negative electrode potential En when the SOC is 0% can be obtained based on the corrected negative electrode potential curve data Dn56. The negative electrode potential En at this time is called En0 (charging information). FIG. 11 is an enlarged view of a main portion of the corrected negative electrode potential curve data Dn56 shown in FIG. The discharge capacity at the discharge end in the corrected negative electrode potential curve data Dn56 is denoted as Qe. Then, the difference between the discharge capacity at the negative electrode potential En0 (charging information), i.e., the discharge capacity at SOC=0%, and the discharge capacity Qe corresponds to the upper limit recoverable capacity and becomes the recovery upper limit capacity expected value data Dn20 for the battery cell 10.

[0048] Returning to FIG. 9, when the process proceeds to step S14, the recoverable capacity calculation unit 74 refers to the capacity recovery database 86. As shown in FIG. 7, the capacity restoration database 86 stores degradation state data D10, restoration upper limit capacity data D20, and capacity restoration result value data D24 in association with each other. Therefore, the capacity recovery database 86 outputs the capacity recovery expectation value data Dn24 corresponding to the current recovery upper limit capacity expectation value data Dn20 (see FIG. 11) and the current degradation state data Dn10.

[0049] Next, when the process proceeds to step S16, the recoverable capacity calculation unit 74 calculates the capacity recovery rate expectation value data Dn22 by dividing the capacity recovery expectation value data Dn24 by the recovery upper limit capacity expectation value data Dn20.

[0050] Next, when the process proceeds to step S18, the recoverable capacity calculation unit 74 transmits the calculated capacity recovery rate expected value data Dn22 and capacity recovery expected value data Dn24 to the user terminal 60 (see FIG. 3A). This allows the user to know what level of capacity recovery rate can be expected if the capacity recovery process is performed on the battery system 56 (see FIG. 1). Of the above-mentioned processes, the processes from steps S2 to S16 are referred to as "diagnosis mode process S100."

[0051] FIG. 12 is a block diagram showing the relationship between the main parts of the server machine 70 and the database unit 80. As shown in FIG. The material property database 82 outputs potential curve data Dn50 based on the degradation state data Dn10, i.e., the operation history data Dn11 and the degradation rate data Dn12. The recovery upper limit capacity calculation unit 72 outputs recovery upper limit capacity expectation value data Dn20 based on the potential curve data Dn50, the cell voltage V, and the cell current I. The capacity recovery database 86 outputs capacity recovery expectation value data Dn24 based on the degradation state data Dn10 and the recovery upper limit capacity expectation value data Dn20. In addition, the recoverable capacity calculation unit 74 outputs capacity recovery rate expectation value data Dn22 by dividing the capacity recovery expectation value data Dn24 by the recovery upper limit capacity expectation value data Dn20.

[0052] 13 and 14 are flowcharts of a capacity recovery processing routine. This routine is started when a command to execute capacity recovery processing is output from the user terminal 60. First, in step S21 of Fig. 13, when the charger 54 is connected to the battery system 56, the charger 54 notifies the server machine 70 of this fact. Next, the charger 54 and the server machine 70 execute the contents of the diagnosis mode process S100 (see Fig. 9).

[0053] When the diagnosis mode process S100 ends, the recoverable capacity calculation unit 74 determines whether or not all of the capacity recovery conditions C1, C2, and C3 listed below are satisfied. C1: The recovery upper limit capacity expected value data Dn20 is equal to or greater than a predetermined value. C2: The capacity deterioration rate SOHQ of each battery cell 10 included in the deterioration rate data D12 is equal to or less than a predetermined value. · C3: No abnormal changes were found in the operation history data Dn11. To further explain the capacity recovery condition C3, the deterioration prediction database 84 (see FIG. 6) records past operation history data D11 and deterioration rate data D12 for each battery cell 10. It is advisable to statistically compare these contents with the currently acquired operation history data Dn11 and deterioration rate data Dn12 to determine whether any abnormal changes have been observed.

[0054] If the determination in step S32 is "No," the process proceeds to step S36 in the server machine 70. The recoverable capacity calculation unit 74 transmits a message to the user terminal 60 indicating that "capacity recovery processing is not possible," and the process of this routine ends. On the other hand, if the determination in step S32 is "Yes," the process proceeds to step S34 in the server machine 70, and the capacity recovery control unit 76 outputs a capacity recovery command SC2 to the charger 54 via the communication module 52.

[0055] When the charger 54 receives the capacity recovery command SC2, the process proceeds to step S22 (capacity recovery process). Here, for the capacity recovery process, the charger 54 executes a CCCV discharge (constant current constant voltage discharge) process until the cell voltage V reaches a predetermined value. Next, when the process proceeds to step S24 in the charger 54, the charger 54 executes intermittent charging or small current charging of the battery pack 20. Next, when the process proceeds to step S24, the charger 54 outputs charging result report data SC4 to the server machine 70, and the process in the charger 54 ends. Here, the charging result report data SC4 is time-series data of the cell voltage V, cell current I, temperature, etc. in the discharging process in step S22 and the charging process in step S24.

[0056] When the server machine 70 receives the charging result report data SC4, the process proceeds to step S38 (see FIG. 14) in the server machine 70. Here, the capacity recovery evaluation unit 78 calculates the recovery upper limit capacity expectation value data Dn20, the discharge amount data Dn30, and the capacity recovery actual value data Dc24 based on the charging result report data SC4.

[0057] Next, when the process proceeds to step S40, the capacity recovery evaluation unit 78 reads out the capacity recovery database 86 (see FIG. 7). That is, the capacity recovery evaluation unit 78 acquires the past recovery upper limit capacity data D20 and the capacity recovery result value data D24 stored in the capacity recovery database 86.

[0058] Next, when the process proceeds to step S42, the capacity recovery evaluation unit 78 performs a statistical comparison process. That is, the capacity recovery evaluation unit 78 performs a statistical comparison process between the currently acquired recovery upper limit capacity expectation value data Dn20 and the past recovery upper limit capacity data D20, and performs a statistical comparison process between the currently acquired capacity recovery actual value data Dc24 and the past capacity recovery actual value data D24. For example, the capacity recovery evaluation unit 78 calculates an average value and a standard deviation of the past recovery upper limit capacity data D20, and compares the calculated average value with the recovery upper limit capacity expectation value data Dn20. Furthermore, the capacity recovery evaluation unit 78 may calculate an average value and a standard deviation of the past capacity recovery actual value data D24, and compare the calculated average value with the capacity recovery actual value data Dc24.

[0059] Next, when the process proceeds to step S44, it is determined whether or not both the recovery upper capacity expectation data Dn20 and the capacity recovery actual value data Dc24 are valid as a result of the statistical comparison process (step S42). For example, when the average value of the recovery upper capacity data D20 is Qa and the standard deviation is σa, if the recovery upper capacity expectation data Dn20 is in the range of "Qa±3σa", it can be determined that the recovery upper capacity expectation data Dn20 is valid, and in other cases, it is not valid. Similarly, when the average value of the capacity recovery actual value data D24 is Qb and the standard deviation is σb, if the capacity recovery actual value data Dc24 is in the range of "Qb±3σb", it can be determined that the capacity recovery actual value data Dc24 is valid, and in other cases, it is not valid.

[0060] If the recovery upper limit capacity expected value data Dn20 or the capacity recovery actual value data Dc24 is invalid, the result in step S44 is determined as "No" and the process proceeds to step S50. Here, the capacity recovery evaluation unit 78 notifies the user terminal 60 of the abnormality, and the process of this routine ends. For example, the capacity recovery evaluation unit 78 may notify the user terminal 60 that "the battery system 56 is abnormal" and that "it is recommended to stop using the battery system 56." The notified content is also displayed on the user terminal 60.

[0061] On the other hand, if both the recovery upper limit capacity expectation value data Dn20 and the capacity recovery actual value data Dc24 are valid, the result of step S44 is determined as "Yes" and the process proceeds to step S46. Here, the capacity recovery evaluation unit 78 updates the contents of the capacity recovery database 86 (see FIG. 7) and the safety judgment database 88 (see FIG. 8) so as to add the recovery upper limit capacity expectation value data Dn20 and the capacity recovery actual value data Dc24.

[0062] Next, when the process proceeds to step S48, the capacity recovery evaluation unit 78 transmits to the user terminal 60 a message indicating that the capacity recovery has been completed and the capacity recovery performance value data Dc24, and the process of this routine ends. In addition, the notified content is displayed on the user terminal 60.

[0063] FIG. 15 is a diagram showing an example of a distribution state of the discharge amount data D30 during the capacity recovery process. In Fig. 15, the horizontal axis represents the discharge amount data D30 during the capacity recovery process, and the vertical axis represents the number of capacity recovery results, i.e., the number of results of capacity recovery. When the standard deviation of the discharge amount data D30 is σc, most of the discharge amount data D30 during the capacity recovery process falls within a range of "±3σb" from its average value (variance = 0). Therefore, if the discharge amount data Dn30 calculated in step S38 (see Fig. 14) exceeds the range of "±3σb", the discharge amount data Dn30 is considered to be invalid.

[0064] FIG. 16 is a diagram showing an example of a distribution state of the recovery upper limit capacity data D20. In Fig. 16, the horizontal axis is the recovery upper limit capacity data D20, and the vertical axis is the number of capacity recovery results, i.e., the number of results of capacity recovery. When the standard deviation of the recovery upper limit capacity data D20 is σa, most of the recovery upper limit capacity data D20 falls within a range of "±3σa" from its average value (variance = 0). Therefore, if the recovery upper limit capacity expectation value data Dn20 calculated in step S38 (see Fig. 14) exceeds the range of "±3σa", the recovery upper limit capacity expectation value data Dn20 is considered to be invalid.

[0065] [Second embodiment] 17 is a block diagram of a battery capacity recovery system 120 according to the second embodiment. In the following description, parts corresponding to those in the first embodiment described above are given the same reference numerals, and the description thereof may be omitted. The configuration of the battery capacity recovery system 120 is similar to that of the battery capacity recovery system 100 of the first embodiment described above (see FIG. 3A), but in this embodiment, a charger 58 is provided instead of the charger 54 of the first embodiment. The charger 58 charges the battery system 56 as necessary, and can operate without being controlled by the server machine 70. For example, when the battery system 56 is applied to a hybrid vehicle, the engine and generator of the hybrid vehicle can be considered to be the charger 58. The configuration of the second embodiment other than that described above is similar to that of the first embodiment.

[0066] FIG. 18 is a flowchart of the diagnosis process in this embodiment. First, unlike the communication module 52 of the first embodiment (see FIG. 9), the communication module 52 attached to the battery system 56 repeatedly executes the process of step S6 during operation of the battery system 56. Then, in step S6, the communication module 52 acquires the state of the battery system 56 and transmits the resulting operation history data Dn11 to the server machine 70.

[0067] In this embodiment, the server machine 70 also refers to the material property database 82 and the deterioration prediction database 84 in step S8 to acquire the potential curve data Dn50. There are various known methods for acquiring the potential curve data Dn50 based on the operation history data Dn11 during normal operation of the battery system 56. In this embodiment, any of these methods may be applied to acquire the potential curve data Dn50. Otherwise, the process contents of steps S8 to S18 in the server machine 70 are the same as those in the first embodiment (see FIG. 9). Of the above-mentioned processes, the processes of steps S6 and S8 to S16 are referred to as "operational diagnosis process S120."

[0068] FIG. 19 is a flowchart of a capacity recovery processing routine in this embodiment. In Fig. 19, the charger 54 and the server machine 70 execute the contents of the operation diagnostic process S120 (see Fig. 18). The process after the operation diagnostic process S120 is similar to that in the first embodiment (see Figs. 13 and 14). That is, after the process of step S34 is completed, when the server machine 70 receives the charging result report data SC4, the process of step S38 (see Fig. 14) and thereafter is executed in the server machine 70.

[0069] [Effects of the embodiment] As described above, according to the first embodiment, the battery capacity recovery system 100 includes a battery system 56 including a secondary battery (20) having a plurality of battery cells 10 connected in series and a battery control device 25 that controls the plurality of battery cells 10, chargers 54, 58 that charge the battery system 56, a processing device (70) connected to a database unit 80 that stores information related to the battery system 56, and a communication device (52) that is connected to the battery system 56 or the chargers 54, 58 and inputs and outputs information between the processing device (70), and when the battery system 56 and the chargers 54, 58 are connected, the processing device (70) receives time-series data of the cell voltage V of the battery cells 10 and The battery cell 10 includes a data acquisition unit 71 that acquires an operation history (Dn11) including time-series data of a cell current I that is a current flowing through the battery cell 10, a recovery capacity calculation unit (72) that calculates a recovery capacity expectation value (Dn20) that is an expectation value for capacity recovery in the secondary battery (20) based on the operation history (Dn11), a capacity recovery control unit 76 that outputs a capacity recovery command SC2 to the secondary battery (20) via the communication device (52) based on the recovery capacity expectation value (Dn20) to cause the secondary battery (20) to execute a capacity recovery process (S22, S24), and a notification unit 77 that transmits to a predetermined terminal device (60) whether the capacity recovery process (S22, S24) is being executed or a schedule for the capacity recovery process (S22, S24). As a result, the recovery capacity expectation value (Dn20), which is an expectation value for capacity recovery in the secondary battery (20), can be calculated and transmitted to the predetermined terminal device (60), so that the capacity of the secondary battery (20) can be appropriately restored.

[0070] According to the second embodiment described above, a battery system 56 including a secondary battery (20) having a plurality of battery cells 10 connected in series and a battery control device 25 that controls the plurality of battery cells 10, a processing device (70) connected to a database unit 80 that stores information related to the battery system 56, and a communication device (52) connected to the battery system 56 and inputting and outputting information between the processing device (70), the processing device (70) receives from the communication device (52) an operation history (Dn11) including time series data of the cell voltage V of the battery cells 10 and time series data of the cell current I, which is the current flowing through the battery cells 10. The system further includes a data acquisition unit 71 that acquires data on the operation history (Dn11), a recovery capacity calculation unit (72) that calculates a recovery capacity expectation value (Dn20) that is an expected value for capacity recovery in the secondary battery (20) based on the operation history (Dn11), a capacity recovery control unit 76 that outputs a capacity recovery command SC2 to the secondary battery (20) via the communication device (52) based on the recovery capacity expectation value (Dn20) to instruct the secondary battery (20) to execute a capacity recovery process (S22, S24), and a notification unit 77 that transmits to a predetermined terminal device (60) whether the capacity recovery process (S22, S24) is being executed or a schedule for the capacity recovery process (S22, S24). This also makes it possible to calculate the recovery capacity expectation value (Dn20), which is an expected value for capacity recovery in the secondary battery (20), and transmit it to the predetermined terminal device (60), thereby making it possible to appropriately recover the capacity of the secondary battery (20).

[0071] Moreover, the battery cell 10 includes a positive electrode 12 and a negative electrode 13, the recovered capacity calculation unit (72) further includes a function for calculating a recovered capacity expected value (Dn20) based on the charging information (En0), the deterioration rate (D12) of the battery cell 10, and the operation history (Dn11) of the battery cell 10, and more preferably further includes a capacity recovery amount prediction correction unit 79 that corrects a calculation algorithm for the recovered capacity expected value (Dn20) based on the charging information (En0), the deterioration rate (D12), the operation history (Dn11), and a capacity recovery actual value (Dc24) that is an actual capacity recovery amount in the secondary battery (20). In this way, the capacity recovery amount prediction correction unit 79 can correct the calculation algorithm for the recovered capacity expected value (Dn20) to an appropriate one.

[0072] Furthermore, it is more preferable that the charging information (En0) is a value correlated with the potential of the negative electrode 13 when the SOC of the battery cell 10 is 0%. This makes it possible to obtain the potential of the negative electrode 13 when the SOC of the battery cell 10 is 0% based on the charging information (En0).

[0073] Moreover, it is more preferable that the processing device (70) further includes an operation history / deterioration rate validity determination unit 75 that determines whether or not the operation history (Dn11) and the deterioration rate (Dn12) of the target secondary battery (20) have a predetermined validity based on a deterioration prediction database 84 that stores a correspondence relationship between the operation history (D11) and the deterioration rate (D12), and the capacity recovery control unit 76 prohibits the execution of the capacity recovery process (S22, S24) when the determination result of the operation history / deterioration rate validity determination unit 75 is negative. This makes it possible to prohibit the execution of the capacity recovery process (S22, S24) when the operation history (Dn11) or the deterioration rate (Dn12) does not have the predetermined validity.

[0074] Moreover, it is more preferable that the processing device (70) further includes a capacity recovery evaluation unit 78 that determines (S44) whether the capacity recovery process (S22, S24) has been successful or not based on the contents of a relationship storage database (88) that stores the relationship between the discharge amount data D30 and the capacity recovery result value data D24, and the relationship between the discharge amount data Dn30 after the capacity recovery process (S22, S24) has been executed and the capacity recovery result value (Dc24). This makes it possible to appropriately determine whether the capacity recovery process (S22, S24) has been successful or not.

[0075] It is more preferable that the relationship memory database (88) does not include data for which the determination result in the capacity recovery evaluation unit 78 is negative. This makes it possible to exclude data for which the determination result in the capacity recovery evaluation unit 78 is negative from the relationship memory database (88).

[0076] Furthermore, it is more preferable that the capacity recovery evaluation unit 78 further includes a function of referring to a capacity recovery database 86 that stores the relationship between the capacity recovery result value data D24 and the recovery upper limit capacity data D20, and judging (S44) whether the capacity recovery process (S22, S24) has been successful or not based on the relationship between the recovered capacity expectation value (Dn20) and the capacity recovery result value (Dc24) after the capacity recovery process (S22, S24) has been completed. This makes it possible to judge whether the capacity recovery process (S22, S24) has been successful or not based on the relationship between the recovered capacity expectation value (Dn20) and the capacity recovery result value (Dc24).

[0077] It is more preferable that the capacity recovery database 86 does not include data for which the determination result in the capacity recovery evaluation unit 78 is negative. This makes it possible to exclude data for which the determination result in the capacity recovery evaluation unit 78 is negative from the capacity recovery database 86.

[0078] More preferably, the notification unit 77 further has a function of notifying the terminal device 60 of the expected restored capacity (Dn20), the actual capacity recovery value (Dc24), and the next capacity recovery time. This enables the notification unit 77 to notify the terminal device 60 of the expected restored capacity (Dn20), the actual capacity recovery value (Dc24), and the next capacity recovery time.

[0079] [Variations] The present invention is not limited to the above-mentioned embodiment, and various modifications are possible. The above-mentioned embodiment is exemplified to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to delete a part of the configuration of each embodiment, or to add or replace other configurations. In addition, the control lines and information lines shown in the figure show those that are considered necessary for explanation, and do not necessarily show all the control lines and information lines necessary on the product. In reality, it may be considered that almost all the configurations are connected to each other. Possible modifications of the above-mentioned embodiment are, for example, as follows.

[0080] (1) The hardware of the user terminal 60, server machine 70, and database unit 80 in the above embodiment can be realized by a general-purpose computer, so programs for executing the various processes shown in the above-mentioned flowcharts, etc. may be stored on a storage medium or distributed via a transmission line.

[0081] (2) In the above embodiments, the processes shown in the flowcharts and the like have been described as software-based processes using a program. However, some or all of the processes may be replaced with hardware-based processes using an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array), etc. [Explanation of symbols]

[0082] 10 Battery Cells 12 Positive electrode 13 Negative electrode 20 Battery pack (secondary battery) 25 Battery control device 52 Communication module (communication device) 54,58 Charger 56 Battery System 60 User terminal (terminal device) 70 Server machine (processing device) 71 Data Acquisition Section 72 Recovery upper limit capacity calculation unit (recovery capacity calculation unit) 74 Recoverable capacity calculation section 75 Operation history and deterioration rate validity judgment section 76 Capacity recovery control section 77 Notification Department 78 Capacity Recovery Evaluation Unit 79 Capacity recovery amount prediction correction unit 80 Database Department 82 Material Properties Database 84 Deterioration Prediction Database 86 Capacity Recovery Database 88 Safety Judgment Database (Relational Memory Database) 100,120 Battery Capacity Recovery System I Cell current V Cell voltage D11 Operation history data (operation history) D12 Deterioration rate data (deterioration rate) D20 Recovery Capacity Data D24 Capacity recovery performance data D30 Discharge amount data En0 Negative electrode potential (charging information) SC2 capacity recovery command Dc24 Capacity recovery performance data (Capacity recovery performance) Dn11 Operation history data (operation history) Dn12 Deterioration rate data (deterioration rate) Dn20 Recovery Upper Capacity Expected Value Data (Recovery Capacity Expected Value) Dn30 discharge data Dn50 potential curve data Dn56 Corrected negative electrode potential curve data (negative electrode potential curve data) S22, S24 steps (capacity recovery process)

Claims

1. A battery system including a secondary battery having a plurality of battery cells connected in series and a battery control device that controls the plurality of battery cells; a charger for charging the battery system; A processing device connected to a database unit that stores information about the battery system; a communication device connected to the battery system or the charger for inputting and outputting information between the battery system and the processing device, The processing device includes: a data acquisition unit that acquires, from the communication device when the battery system and the charger are connected, an operation history including time series data of a cell voltage of the battery cell and time series data of a cell current that is a current flowing through the battery cell; a recovery capacity calculation unit that calculates a recovery capacity expectation value, which is an expectation value of capacity recovery in the secondary battery, based on the operation history; a capacity recovery control unit that outputs a capacity recovery command to the secondary battery via the communication device based on the recovery capacity expected value, the capacity recovery command instructing the secondary battery to execute a capacity recovery process; a notification unit that transmits to a predetermined terminal device whether the capacity recovery process is being executed or not, or a schedule of the capacity recovery process. A battery capacity recovery system comprising:

2. The battery cell includes a positive electrode and a negative electrode, The recovery capacity calculation unit further has a function of calculating the recovery capacity expectation value based on charging information, a deterioration rate of the battery cell, and the operation history of the battery cell, The battery further includes a capacity recovery amount prediction correction unit that corrects a calculation algorithm of the recovery capacity expectation value based on the charging information, the deterioration rate, the operation history, and a capacity recovery actual value that is an actual capacity recovery amount in the secondary battery.

2. The battery capacity recovery system according to claim 1 .

3. The charging information is a value correlated with the potential of the negative electrode when the SOC of the battery cell is 0%.

3. The battery capacity recovery system according to claim 2.

4. the processing device further includes an operation history / deterioration rate validity determination unit that determines whether the operation history and the deterioration rate of a target secondary battery have a predetermined validity based on a deterioration prediction database that stores a correspondence relationship between the operation history and the deterioration rate; The capacity recovery control unit prohibits the execution of the capacity recovery process when a result of the determination by the operation history / deterioration rate validity determination unit is negative.

4. The battery capacity recovery system according to claim 2 or 3.

5. The processing device further includes a capacity recovery evaluation unit that determines whether the capacity recovery process has been successful based on the contents of a relationship storage database that stores the relationship between the discharge amount data and the capacity recovery result value data, and the relationship between the discharge amount data after the capacity recovery process has been executed and the capacity recovery result value.

5. The battery capacity recovery system according to claim 2, wherein the battery capacity recovery system comprises:

6. The relational storage database does not include data in the case where the result of the determination in the capacity recovery evaluation unit is negative.

6. The battery capacity recovery system according to claim 5.

7. The capacity recovery evaluation unit is The capacity recovery database stores the relationship between the capacity recovery result value data and the recovery upper limit capacity data, and determines whether the capacity recovery process has been successful based on the relationship between the recovered capacity expectation value and the capacity recovery result value after the capacity recovery process is completed.

7. The battery capacity recovery system according to claim 5 or 6.

8. The capacity recovery database does not include data in cases where the result of the determination in the capacity recovery evaluation unit is negative.

8. The battery capacity recovery system according to claim 7.

9. A battery system including a secondary battery having a plurality of battery cells connected in series and a battery control device that controls the plurality of battery cells; A processing device connected to a database unit that stores information about the battery system; a communication device connected to the battery system for inputting and outputting information between the battery system and the processing device, The processing device includes a data acquisition unit that acquires an operation history including time series data of a cell voltage of the battery cell and time series data of a cell current that is a current flowing through the battery cell from the communication device; and a recovery capacity calculation unit that calculates a recovery capacity expectation value, which is an expectation value of capacity recovery in the secondary battery, based on the operation history; a capacity recovery control unit that outputs a capacity recovery command to the secondary battery via the communication device based on the recovery capacity expected value, the capacity recovery command instructing the secondary battery to execute a capacity recovery process; a notification unit that transmits to a predetermined terminal device whether the capacity recovery process is being executed or not, or a schedule of the capacity recovery process. A battery capacity recovery system comprising:

10. The notification unit further has a function of notifying the terminal device of the expected restored capacity value, the actual capacity restoration value, and the next capacity restoration time.

9. The battery capacity recovery system according to claim 2, wherein the battery capacity recovery system comprises:

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