JP2019200889A - Battery system - Google Patents

Abstract

To provide a battery system including a secondary battery comprising a CID, the battery system inhibiting the CID from being actuated before notifying a user of reaching a state in which the CID can be actuated.SOLUTION: An ECU calculates a conduction charge amount Q during a period in which a battery voltage VB exceeds a threshold voltage Va (S111). The ECU reads out a first map and collates the first map with the conduction charge amount Q calculated at S111 to estimate an addition agent decomposition amount A (S113). The ECU reads out a second map and collates the second map with the addition agent decomposition amount A calculated at S113 to calculate a threshold correction amount ΔDth (S115). The ECU corrects a threshold Dth using the correction amount ΔDth calculated at S115 (S117).SELECTED DRAWING: Figure 12

Description

  The present disclosure relates to a battery system including a secondary battery provided with a current interruption mechanism.

  Some secondary batteries mounted on electric vehicles and the like include a current interrupt device (CID) that interrupts electrical connection with the outside. The CID is configured to be activated when the internal pressure of the secondary battery becomes a predetermined value or more.

  Japanese Patent Laying-Open No. 2006-139484 (Patent Document 1) discloses a battery system including a secondary battery having a CID. This battery system has information that defines the usable time (threshold time) at the average temperature of the secondary battery, and the CID may be activated when the use time at the average temperature exceeds the threshold time. It is estimated that the error has been reached and notification is made. By notifying when it is estimated that the CID is likely to operate, the user can take measures such as replacing the secondary battery before the CID operates.

JP-A-2006-139484 JP 2014-203781 A

  It is known that secondary batteries gradually generate gas inside and increase the internal pressure when used. For this reason, the increase in internal pressure due to the use of the secondary battery may cause the CID to gradually accumulate and cause the CID to operate.

  In the battery system of Patent Document 1, the usage time of the secondary battery is based on the progress (accumulated amount of deterioration) of the CID when the secondary battery is used in a predetermined usage region. Notification is made when the threshold time is exceeded. Hereinafter, a predetermined use area is also referred to as a “normal use area”. Note that “normal” means, for example, that the secondary battery is not overcharged / overdischarged, and that the battery temperature is within a design guarantee value.

  However, for example, an abnormality (use outside the normal use region) may occur such that the secondary battery is overcharged or an instantaneous surge voltage is generated. In such a case, when the battery voltage exceeds a threshold voltage at which the electrolysis of the additive contained in the electrolyte of the secondary battery is started, gas is generated due to the electrolysis of the additive and the secondary battery is generated. An increase in the internal pressure of the battery can be promoted. Due to the increase in the internal pressure, the deterioration of CID is promoted and the time until the operating point where the CID operates can be shortened.

  In the battery system disclosed in Patent Document 1, the deterioration of CID accumulated due to the increase in internal pressure due to the use of the secondary battery outside the normal use range is not taken into consideration, and the battery system is used at a predetermined threshold time. Notification is given when the time is reached. Therefore, there is a concern that the CID will be activated before the threshold time for notification to the user comes.

  The present disclosure has been made in order to solve the above-described problem, and the purpose of the present disclosure is to inform a user that a state where the CID may operate is reached in a battery system including a secondary battery having the CID. This is to prevent the CID from operating before notification.

  A battery system according to the present disclosure detects a secondary battery having a current cutoff mechanism configured to cut off an electrical connection to the outside when an internal pressure increases, and battery information indicating a state of the secondary battery. A monitoring unit configured as described above, and a control device that performs notification when the usage time of the secondary battery reaches a threshold time for the amount of deterioration of the current interrupt mechanism to reach a threshold value. The control device stores in advance correlation information indicating the relationship between the usage time and the amount of deterioration of the current interrupt mechanism when the secondary battery is used within a predetermined usage region. Based on the correlation information, the control device performs notification when the usage time of the secondary battery reaches a threshold time. The control device estimates the amount of decomposition of the additive contained in the electrolyte of the secondary battery when the secondary battery is used outside the predetermined use area, using the battery information. The control device corrects the threshold value downward according to the estimated amount of decomposition.

  According to the above configuration, the control device includes the usage time of the secondary battery and the amount of deterioration of the current interruption mechanism (CID) when the secondary battery is used in a predetermined usage area (normal usage area). Correlation information indicating the relationship is prepared and stored in advance. Then, based on the correlation information, notification is given when the usage time of the secondary battery reaches the threshold time. The threshold time is the time for the CID degradation amount to reach the threshold in the correlation information.

  When the secondary battery is used outside the normal use area (for example, overcharge), gas is generated in the secondary battery and the internal pressure rises, so that the CID deteriorates more than the information defined by the correlation information. Thus, the time required to reach the CID operating point can be shortened. Therefore, since the amount of decomposition of the additive and the amount of gas generated are correlated, the control device uses the battery information acquired from the monitoring unit to add when the secondary battery is used outside the normal use area. The decomposition amount of the agent is calculated, and the threshold value is corrected according to the calculated decomposition amount. As the threshold is corrected, the threshold time correlated with the threshold is also corrected. As described above, even if the time until the operating point at which the CID is activated due to use outside the normal use area is earlier than the initial threshold time, the correlation information and the corrected threshold value are used. A new threshold time (corrected threshold time) can be set. That is, the threshold time is changed so as to be shortened as the threshold value is corrected downward. Therefore, it is possible to prevent the CID from operating before the user is notified.

  According to the present disclosure, in a battery system including a secondary battery having a CID, it is possible to suppress the CID from operating before notifying the user that the CID has reached a state where the CID may be activated. Can do.

1 is a diagram schematically showing an overall configuration of a vehicle equipped with a battery system according to an embodiment. It is a top view of the battery which concerns on embodiment. It is a schematic sectional drawing of the battery which concerns on embodiment. It is a figure which shows an example of correlation information in case a battery is used within a normal use area | region. It is a figure which shows the creep characteristic of CID. It is a figure which shows roughly the correlation information in case use of the battery out of a normal use area | region generate | occur | produces. It is a figure for demonstrating schematically an example when the use of the battery outside a normal use area | region generate | occur | produces. It is a temperature characteristic map which shows the relationship between battery temperature and a threshold voltage. It is a figure which shows an example of the 1st map which concerns on embodiment. It is a figure which shows an example of the 2nd map which concerns on embodiment. It is the figure which showed the correlation information which performed correction | amendment of the threshold value in embodiment. It is a flowchart which shows an example of the process of calculation of the correction value of a threshold value, and alerting | reporting which are performed in ECU which concerns on embodiment.

  Hereinafter, the present embodiment will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a diagram schematically showing an overall configuration of a vehicle 1 equipped with a battery system according to the present embodiment. The vehicle 1 is an electric vehicle such as an electric vehicle, a hybrid vehicle, a plug-in hybrid vehicle, and a fuel cell vehicle. In the present embodiment, an example in which the vehicle 1 is an electric vehicle will be described.

  The vehicle 1 includes a power storage device 10, a system main relay 20, a power control unit (hereinafter also referred to as “PCU (Power Control Unit)”) 40, a motor generator (MG) 50, Drive wheel 60, ECU (Electronic Control Unit) 100, monitoring unit 200, and notification device 400 are provided. The battery system includes a power storage device 10, an ECU 100, a monitoring unit 200, and a notification device 400.

  The power storage device 10 is configured by stacking a plurality of batteries 11 (see FIG. 2) in series. The battery 11 is a chargeable / dischargeable secondary battery. The battery 11 is, for example, a nickel metal hydride battery or a lithium ion battery. The battery 11 may be a battery having a liquid electrolyte between the positive electrode and the negative electrode, or may be a battery having a solid electrolyte (all solid battery). In the present embodiment, an example in which the battery 11 is a lithium ion battery will be described. Details of the battery 11 will be described with reference to FIGS. 2 and 3.

  FIG. 2 is a plan view of the battery 11 according to the present embodiment. FIG. 3 is a schematic cross-sectional view of the battery 11 according to the present embodiment.

  As shown in FIGS. 2 and 3, the battery 11 includes a battery case 110, an electrode body 123 as a battery element, a negative external terminal 116 and a current collector 128, and a positive external terminal 113 and a current collector 127. Is provided. The battery case 110 includes a bottomed rectangular tube-shaped storage portion 132 and a sealing body 131 that seals the opening of the storage portion 132. The battery case 110 accommodates the electrode body 123 and the nonaqueous electrolyte therein. The external terminals 113 and 116 are attached to the sealing body 131 of the battery case 110.

  The electrode body 123 includes a positive electrode core body, a negative electrode core body, and a separator (all not shown), and the positive electrode core body and the negative electrode core body are wound through the separator. A negative electrode core exposed portion 126 and a positive electrode core exposed portion 125 are provided at both ends of the electrode body 123, respectively.

  The negative electrode core exposed portion 126 is electrically connected to the external terminal 116 via the current collector 128. The positive electrode core exposed portion 125 is electrically connected to the external terminal 113 via a current collector 127 and a current interrupt mechanism (CID) 300.

  In addition, the battery case 110 is provided with an injection hole (not shown) through which a nonaqueous electrolyte is injected. The nonaqueous electrolyte includes a gas generating additive that generates gas by being electrolyzed at the positive electrode when a predetermined voltage or higher (hereinafter referred to as “threshold voltage Va”) is applied. For example, an aromatic compound is used as the gas generating additive.

  The CID 300 is, for example, a pressure-type current interruption mechanism, and interrupts electrical connection with the outside when the internal pressure of the battery 11 (battery case 110) increases. The CID 300 only needs to be configured to cut a conductive path from at least one of the external terminals 113 and 116 to the electrode body 123 when the pressure in the battery case 110 rises, and is limited to a specific shape. Is not to be done. In the present embodiment, as shown in FIG. 3, CID 300 is configured to cut a conductive path from external terminal 113 for the positive electrode to electrode body 123. The configuration of the CID 300 will be specifically described below.

  The CID 300 includes a reversing plate 310 and a metal plate 320. The reversing plate 310 has a shape in which the central portion 311 protrudes toward the metal plate 320, the central portion 311 is joined to the metal plate 320, and both are electrically connected. Further, the peripheral portion of the reversing plate 310 is electrically connected to the external terminal 113 via the lead terminal 330.

  Before the CID 300 operates, during discharging, current flows in the order of the current collector 127, the metal plate 320, the reversing plate 310, the lead terminal 330, and the external terminal 113 for positive electrode. Thereby, electric power is supplied from the battery 11 to the outside. When charging, a current flows in the opposite direction. Such a conductive path between the external terminal 113 for the positive electrode and the electrode body 123 is formed.

  The CID 300 further includes an insulating case 340 formed of plastic or the like. The insulating case 340 has an opening, and the central portion 311 of the reversing plate 310 is fitted into the opening. Thereby, a sealed space S is formed by the reversing plate 310 and the insulating case 340. A peripheral portion of the reversing plate 310 is fixed to the insulating case 340. A part of the lower surface of the reversing plate 310 (hereinafter also referred to as a “pressure operation unit”) is exposed to the inside of the battery case 110 from the opening and is pressed by the pressure in the battery case 110.

  When the internal pressure of the battery case 110 rises, the pressure operating part of the reversing plate 310 is pressed. In other words, the central portion 311 of the reversing plate 310 receives pressure in a direction away from the metal plate 320. The magnitude of the force with which the pressure operating portion of the reversing plate 310 is pressed increases as the internal pressure of the battery case 110 increases.

  When the internal pressure of the battery case 110 exceeds a certain level, the central portion 311 of the reversing plate 310 is reversed in a direction away from the metal plate 320, and the electrical connection between the reversing plate 310 and the metal plate 320 is interrupted. As a result, electrical conduction between the positive external terminal 113 and the electrode body 123 is interrupted.

  Returning to FIG. 1, the monitoring unit 200 includes, for example, a voltage sensor, a current sensor, a temperature sensor, and the like. The voltage sensor detects the voltage of each battery 11 included in power storage device 10 and outputs a signal VB indicating the detection result to ECU 100. The current sensor detects a current input / output to / from power storage device 10 and outputs a signal IB indicating the detection result to ECU 100. The temperature sensor detects the temperature of each battery 11 included in power storage device 10 and outputs a signal TB indicating the detection result to ECU 100.

  System main relay 20 has one end electrically connected to power storage device 10 and the other end electrically connected to PCU 40. The system main relay 20 is switched between open and closed states according to a control signal from the ECU 100.

  PCU 40 collectively represents a power conversion device for receiving electric power from power storage device 10 and driving motor generator 50. For example, PCU 40 includes an inverter for driving motor generator 50, a converter that boosts the power output from power storage device 10 and supplies the boosted power to the inverter.

  Motor generator 50 is an AC rotating electric machine, for example, a permanent magnet type synchronous motor including a rotor in which permanent magnets are embedded. The rotor of motor generator 50 is mechanically connected to drive wheel 60 via a power transmission gear (not shown). The motor generator 50 can generate electric power by the rotational force of the drive wheels 60 during the regenerative braking operation of the vehicle 1, and outputs the generated electric power to the PCU 40.

  The notification device 400 includes, for example, a display of a vehicle-mounted navigation system, a head-up display, and the like, and notifies various information according to a control signal from the ECU 100. For example, the notification device 400 may be notified by displaying characters on the display of the navigation system or may be notified by voice.

  The ECU 100 includes a CPU (Central Processing Unit) 100a, a memory (more specifically, a ROM (Read Only Memory) and a RAM (Random Access Memory)) 100b, and an input / output port (not shown) for inputting and outputting various signals. Z)). The ECU 100 controls each device based on signals from each sensor and device, a program stored in the memory 100b, and the like. Various controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuit).

  ECU 100 further includes a timer circuit 100c. The timer circuit 100 c measures the usage time of the battery 11. The usage time in the present embodiment corresponds to an elapsed time after the battery 11 is mounted on the vehicle 1. The measured usage time is stored in the memory 100b. In addition, the timer circuit 100c measures the time during which the battery voltage VB exceeds the threshold voltage Va.

  Even when the battery 11 is used in a predetermined use region (normal use region), the electrolyte is electrolyzed, so that gas is gradually generated inside to increase the internal pressure. It has been. As a result, even when the battery 11 is used in the normal use region, the deterioration amount (details will be described later) gradually accumulates in the CID 300 due to the increase in internal pressure, and the CID 300 may operate. obtain.

  Therefore, when the ECU 100 estimates that there is a possibility that the CID 300 is activated even though the battery 11 is being used in the normal use region, the ECU 100 controls the notification device 400 to notify the user of the CID 300. Notify that it may work. Thus, the user who has received the notification can take measures such as replacing the battery 11 before the CID 300 operates. A method for estimating that the CID 300 is likely to operate will be specifically described below.

  The ECU 100 estimates that the CID 300 may operate using the correlation information stored in the memory 100b in advance. The correlation information is information indicating the relationship between the usage time of the battery 11 and the deterioration amount of the CID 300.

  FIG. 4 is a diagram illustrating an example of correlation information when the battery 11 is used in the normal use region. The correlation information is a map created by design data of the battery 11 or experimental data performed in advance. The horizontal axis of the correlation information indicates the usage time T of the battery 11, and the vertical axis indicates the deterioration amount D of the CID 300.

  The threshold value Dth shown in FIG. 4 is a value used to determine whether or not the CID 300 is likely to operate despite the battery 11 being used in the normal use region. The threshold value Dth is set to be a predetermined amount smaller than the operating point at which the CID 300 operates, as will be described later. By using the correlation information, the threshold time Tth when the battery 11 is used in the normal use region can be obtained. The threshold time Tth is a use time until the deterioration amount D of the CID 300 reaches the threshold Dth.

  As the deterioration amount D of the CID 300, for example, the damage amount accumulated in the CID 300 is used. As an example, a specific method for calculating the deterioration amount D of the CID 300 as the damage amount will be described with reference to FIG. FIG. 5 is a diagram showing the creep characteristics of CID300. A curve L5 shown in this figure is a creep line showing the relationship between the internal pressure and time of the battery 11 (battery case 110) when reaching the operating point at which the CID 300 operates. The horizontal axis represents time, and the vertical axis represents internal pressure. The curve L5 can be known from, for example, design data or experimental data of CID300.

  Referring to FIG. 5, curve L5 indicates that, for example, if the internal pressure of battery 11 is PA, CID 300 reaches the operating point if internal pressure PA continues to be applied for time tA, and the internal pressure of battery 11 is PB. Then, if the internal pressure PB continues to be applied for a time tB, it indicates that the CID 300 reaches the operating point.

  For example, the deterioration amount D of CID300 is defined based on the curve L5. A specific example will be described. For example, when the curve L5 indicates time = 1000 h when the internal pressure = 0.2 MPa, the state in which the internal pressure of the battery 11 is 0.2 MPa continues for 8 h (8 hours). . The deterioration amount D of CID 300 at this time is calculated as D = (8h) / (1000h) × 100 = 0.8%. Further, the deterioration amount D of the CID 300 is accumulated. Therefore, when the internal pressure and time of the battery 11 are acquired in a plurality of times, the deterioration amount D is obtained by integrating the deterioration amounts D of the CID 300 calculated in each of the plurality of times.

  Returning to FIG. 4, the ECU 100 sets, as the threshold value Dth, a deterioration amount that is smaller by a predetermined amount ΔD than the deterioration amount D of the CID 300 corresponding to the operating point at which the CID 300 calculated as described in FIG. . By setting the threshold value Dth in this way, a certain time is allowed until the CID 300 is activated after the notification that the battery 11 has been used for the threshold time Tth and notification is made. Thus, the user who has received the notification can take measures such as replacing the battery 11 until the CID 300 is activated.

  However, for example, an abnormality (use outside the normal use region) may occur such that the battery 11 is overcharged or an instantaneous surge voltage is generated. FIG. 6 is a diagram schematically showing correlation information when the battery 11 is used outside the normal use region. A broken line L6A shown in FIG. 6 indicates the correlation information of FIG. That is, the broken line L6A indicates the relationship between the usage time and the deterioration amount of the CID 300 when the battery 11 is used in the normal use region. A solid line L6B shown in FIG. 6 indicates correlation information when the battery 11 is used outside the normal use region. That is, the solid line L6B indicates the relationship between the usage time and the amount of deterioration of the CID 300 when the battery 11 is used outside the normal use area.

  When the battery 11 is used outside the normal use range, when the battery voltage VB exceeds the threshold voltage Va at which the electrolysis of the gas generating additive contained in the electrolyte of the battery 11 is started, gas is generated and the battery An increase in the internal pressure of 11 can be promoted. That is, as described above, even when the battery 11 is used in the normal use region, the electrolyte is electrolyzed to gradually generate gas and increase the internal pressure. When the battery 11 is used, in addition to an increase in internal pressure due to the electrolysis of the electrolyte, an increase in internal pressure due to the electrolysis of the gas generating additive may occur. As shown in FIG. 6, the increase in internal pressure due to the electrolysis of the gas generating additive accumulates more deterioration amount of CID300 than in the normal use region. . When accumulation of the deterioration amount of CID300 due to use outside the normal use area occurs, the correlation information (broken line L6A) is shifted to the solid line L6B. Thus, the threshold time until the deterioration amount D of the CID 300 reaches the threshold value Dth is changed from Tth to Tth1 (Tth> Tth1). This indicates that when the operating point at which the CID 300 operates is considered, the use time until the operating point is reached is shortened.

  On the other hand, the notification to the user by the notification device 400 is performed when the usage time of the battery 11 reaches the threshold time Tth. For this reason, the CID 300 may be operated near the use time Tth1 before the threshold time Tth for notification to the user arrives.

  Therefore, in the present embodiment, when it is estimated that the use of the battery 11 outside the normal use region has occurred and the deterioration amount D of the CID 300 has been accumulated, the correlation information is determined according to the accumulated deterioration amount. The threshold value Dth is corrected. Along with the correction of the threshold value Dth, the threshold time, which is the time until the deterioration amount of the CID 300 reaches the threshold value, is also corrected, so that the notification device 400 notifies the user before the CID 300 operates. Can be performed. Hereinafter, correction of the threshold value Dth of the correlation information will be specifically described.

  FIG. 7 is a diagram for schematically explaining an example when the battery 11 is used outside the normal use region. In FIG. 7, the horizontal axis represents time t, and the vertical axis represents battery voltage VB and battery current IB. In FIG. 7, as an example of the use of the battery 11 outside the normal use region, a case where a surge voltage is generated and the battery voltage VB exceeds the threshold voltage Va at which the electrolysis of the gas generating additive is started is shown. ing.

  As shown by the curve LV in FIG. 7, the battery voltage VB exceeds the threshold voltage Va between time t1 and time t2. Further, the battery voltage VB exceeds the threshold voltage Va between the time t3 and the time t4. While the battery voltage VB exceeds the threshold voltage Va, the gas generating additive is electrolyzed to generate gas, and the internal pressure of the battery 11 increases.

  The threshold voltage Va changes depending on the battery temperature TB. FIG. 8 is a temperature characteristic map showing the relationship between the battery temperature TB and the threshold voltage Va. The temperature characteristic map shown in FIG. 8 is determined according to the type (characteristic) of the gas generating additive, and the theoretical data or experimental data is stored in the memory 100b of the ECU 100 as a temperature characteristic map.

  Further, the memory 100b has a first map showing the relationship between the energized charge amount Q and the additive decomposition amount A shown in FIG. 9, and a correction amount ΔDth of the additive decomposition amount A and the threshold value Dth shown in FIG. A second map showing the relationship between the two is stored. The energized charge amount Q indicates an accumulated charge amount during a period in which the battery voltage VB exceeds the threshold voltage Va, and is defined by the following formula (1).

  The first map is determined according to the type (characteristic) of the gas generating additive, and the first map is created for each type of gas generating additive used and stored in the memory 100b. The first map is mapped by calculating the amount by which the gas generating additive is decomposed by the energized charge amount Q of the battery 11 through experiments or the like.

  The second map is, for example, the relationship between the increase in the internal pressure of the battery 11 according to the gas generation amount and the deterioration amount D of CID accumulated by the increase in the internal pressure (for example, the damage amount described in FIG. 5), and The correction amount ΔDth to be corrected for the threshold value Dth is calculated and mapped using the correlation information.

  Returning to FIG. 7, in the present embodiment, the ECU 100 calculates the energized charge amount Q while the voltage VB exceeds the threshold voltage Va. By calculating the energized charge amount Q, the additive decomposition amount A can be calculated by collating the calculated energized charge amount Q with the first map. Then, the correction amount ΔDth of the threshold value Dth can be calculated by collating the calculated additive decomposition amount A with the second map.

  For example, the energized charge amount Q1 between the time t1 and the time t2 is obtained by integration of the battery current IB and is represented by the following formula (1). The amount of energized charge Q2 between time t3 and time t4 is obtained in the same manner.

  As described above, the energized charge amount Q1 can be calculated, and the correction amount ΔDth1 of the threshold value Dth can be calculated using the calculated energized charge amount Q1, the first map, and the second map. Further, the energization charge amount Q2 can be calculated, and the correction amount ΔDth2 of the threshold value Dth can be calculated using the calculated energization charge amount Q2, the first map, and the second map.

  FIG. 11 is a diagram showing correlation information obtained by correcting the threshold value Dth in the present embodiment. Referring to FIGS. 7 and 11, first, since there is a voltage excess (VB ≧ Va) from time t1 to time t2, the threshold value is changed from Dth by correcting the threshold value Dth by the correction amount ΔDth1. It is corrected to Dth1. Along with this, the threshold time is corrected from Tth to Tth1. Further, since there is a voltage excess (VB ≧ Va) between time t3 and time t4, the threshold value Dth1 is corrected by the correction amount ΔDth2, so that the threshold value is corrected from Dth1 to Dth2. Accordingly, the threshold time is corrected from Tth1 to Tth2.

  As described above, in the present embodiment, the deterioration of CID 300 accumulates due to the use of battery 11 outside the normal use region, and the time until reaching the operating point of CID 300 is earlier than the initial threshold time Tth. In addition, the threshold Dth of the correlation information is corrected. As the threshold value Dth is corrected, the threshold time Tth is also corrected, so that the notification device 400 can notify the user before the CID 300 operates.

  FIG. 12 is a flowchart showing an example of calculation and notification processing of the correction amount ΔDth of the threshold value Dth executed in the ECU 100 according to the present embodiment. This flowchart is called and executed in the ECU 100 at every predetermined calculation cycle. Each step of the flowchart shown in FIG. 12 will be described with respect to a case where it is realized by software processing by the ECU 100, but a part or all of the steps may be realized by hardware (electric circuit) produced in the ECU 100.

  The ECU 100 acquires battery information (battery voltage VB, battery current IB, battery temperature TB) from the monitoring unit 200 (step 101; hereinafter, step is abbreviated as “S”). The ECU 100 reads the temperature characteristic map (FIG. 8) from the memory 100b, collates the battery temperature TB with the temperature characteristic map, and calculates the threshold voltage Va corresponding to the battery temperature TB (S102).

  The ECU 100 determines whether or not the battery voltage VB is equal to or higher than the threshold voltage Va (S103). If the battery voltage VB is less than the threshold voltage Va (NO in S103), the ECU 100 ends the process because the battery 11 is used in the normal use region and there is no need to correct the correlation information threshold Dth.

  When battery voltage VB is equal to or higher than threshold voltage Va (YES in S103), ECU 100 starts time measurement (S105), acquires battery current IB at this time from monitoring unit 200, and stores it in memory 100b as an integrated current value. Store (S106).

  Next, the ECU 100 determines whether or not the state where the battery voltage VB exceeds the threshold voltage Va continues (S107). ECU 100 continues the time measurement when battery voltage VB exceeds threshold voltage Va (YES in S107), acquires battery current IB, and stores the current stored in memory 100b. Add to the integrated value.

  When the battery voltage VB does not continue to exceed the threshold voltage Va, that is, when the battery voltage VB becomes less than the threshold voltage Va (NO in S107), the ECU 100 ends the time measurement (S109). .

  The ECU 100 reads the current integrated value integrated during the time measurement from the memory 100b, and calculates the current integrated value as the energization charge amount Q (S111).

  The ECU 100 reads the first map (FIG. 9) from the memory 100b and collates the energized charge amount Q calculated in S111 with the first map to estimate the additive decomposition amount A (S113).

  The ECU 100 reads the second map (FIG. 10) from the memory 100b, collates the additive decomposition amount A estimated in S113 with the second map, and calculates the correction amount ΔDth of the threshold Dth (S115).

  The ECU 100 corrects the correlation information threshold Dth to the corrected threshold DthA using the correction amount ΔDth calculated in S115, and calculates a threshold time (corrected threshold time) TthA corresponding to the corrected threshold DthA ( S119). When the process of this flowchart is executed next time, the threshold value is corrected with respect to the corrected threshold value DthA calculated this time.

  The ECU 100 determines whether or not the current usage time of the battery 11 exceeds the corrected threshold time TthA (S121).

  If the current usage time of battery 11 exceeds corrected threshold time TthA (YES in S121), ECU 100 controls notification device 400 to notify the user (S122). On the other hand, when current usage time of battery 11 does not exceed corrected threshold time TthA (NO in S121), ECU 100 has not reached a state in which CID 300 may possibly operate, and thus does not perform notification. The process ends.

  As described above, in the battery system according to the present embodiment, the deterioration of the CID 300 accumulates due to the use of the battery 11 outside the normal use region, and the time until the operating point of the CID 300 is reached is longer than the initial threshold time Tth. If it is earlier, the correlation information threshold Dth is corrected. As the threshold value Dth is corrected, the threshold time is also corrected, so that the notification device 400 can notify the user before the CID 300 operates. Thus, it is possible to prevent the CID 300 from operating before notification to the user.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present disclosure is shown not by the above description of the embodiments but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

  DESCRIPTION OF SYMBOLS 1 Vehicle, 10 Power storage device, 11 Battery, 20 System main relay, 50 Motor generator, 60 Drive wheel, 100 ECU, 100a CPU, 100b Memory, 100c Timer circuit, 110 Battery case, 113, 116 External terminal, 123 Electrode body, 125 positive electrode core exposed part, 126 negative electrode core exposed part, 127,128 current collector, 131 sealing body, 132 accommodating part, 200 monitoring unit, 300 current interruption mechanism, 310 reversing plate, 311 central part, 320 metal plate, 330 lead terminal, 340 insulation case, 400 alarm device, S sealed space.

Claims (1)

A secondary battery having a current interrupting mechanism configured to interrupt electrical connection with the outside when the internal pressure increases;
A monitoring unit configured to detect battery information indicating a state of the secondary battery;
A control device that notifies when the usage time of the secondary battery has reached a threshold time for the amount of deterioration of the current interrupt mechanism to reach a threshold;
The controller is
In the case where the secondary battery is used in a predetermined use area, correlation information indicating a relationship between the usage time and the deterioration amount of the current interrupt mechanism is stored in advance.
Based on the correlation information, when the usage time of the secondary battery reaches the threshold time, the notification is performed,
Using the battery information, when the secondary battery is used outside the use area, estimate the decomposition amount of the additive contained in the electrolyte of the secondary battery,
A battery system that corrects the threshold value downward in accordance with the estimated amount of decomposition.

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