JP2018196315A - Control method of battery pack module - Google Patents

Abstract

To provide a control method of a battery pack module capable of suppressing circulating current.SOLUTION: Disclosed control method is a control method of a battery pack module configured including multiple electric cells which are electrically connected to each other in parallel. The control method is configured so as to, when an occurrence of an internal short circuit is detected on any one of the multiple electric cells and when the temperature of the electric cell on which the internal short circuit has occurred is a melting point of a separator or less, control to switch over to a battery-less traveling and to heat the electric cell on which the internal short circuit has occurred up to a temperature not less than the boiling point of the electrolytic solution and not more than the melting point of the separator to thereby activate a current shut-off mechanism.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for controlling an assembled battery module.

  Lithium-ion secondary batteries, nickel-metal hydride batteries, and other secondary batteries that can be obtained at a light weight and high energy density are used as unit cells, and assembled batteries that are formed by connecting a plurality of unit cells provide high output. As a power source, it is preferably used as a vehicle-mounted power source or a personal computer and a portable terminal. For example, Patent Document 1 discloses a power storage system configured by arranging a plurality of single cells and connecting the single cells in parallel as an example of an assembled battery for mounting on a vehicle.

JP 2014-1117021 A

By the way, in each single battery constituting the assembled battery, for example, a foreign substance mixed in the single battery may penetrate the separator and bridge between the positive and negative electrodes, thereby causing a minute internal short circuit. When such a short circuit occurs, a voltage drop occurs in the single cells. Therefore, when the single cells are connected in parallel, it is assumed that current flows from the other single cells connected in parallel to the single short-circuited single cells. Since such a sneak current (circulating current) flows in a concentrated manner at the short-circuited portion, if left as it is, the separator may be melted and contracted by Joule heat generation, which may increase the internal short circuit. Accordingly, there is a need for a technique for suppressing circulating current.
This invention is made | formed in view of this point, The main objective is the assembled battery module which can suppress a circulating current in the assembled battery comprised by connecting the several cell electrically in parallel. It is to provide a control method.

  The control method proposed here is an assembled battery module mounted on a vehicle capable of switching between battery travel that travels using the power of the electric motor and battery-less travel that travels without using the power of the electric motor. This is a control method. The assembled battery module includes a plurality of single cells electrically connected in parallel. Each of the plurality of unit cells is provided in an electrode body in which a positive electrode and a negative electrode are stacked via a separator, an electrolytic solution, a battery case containing the electrode body and the electrolytic solution, and the battery case. A current interrupting mechanism for interrupting electrical connection between the electrode body and the external terminal when the internal pressure of the battery case and the external terminal electrically connected to the electrode body is higher than a predetermined pressure And. The control method detects the occurrence of an internal short circuit in any of the plurality of single cells, and the batteryless running when the temperature of the single short circuited cell is equal to or lower than the melting point of the separator. After switching, the internal short-circuited unit cell is heated to a temperature not lower than the boiling point of the electrolytic solution and not higher than the melting point of the separator, and control for operating the current interrupting mechanism is performed. According to such a configuration, the circulating current can be effectively suppressed.

  In the present specification, the “unit cell” is a term indicating individual power storage elements that can be connected to each other to form an assembled battery, and includes batteries and capacitors having various compositions unless otherwise specified. The “secondary battery” generally refers to a battery that can be repeatedly charged, and includes so-called storage batteries such as lithium ion secondary batteries and nickel metal hydride batteries. A power storage element constituting a lithium ion secondary battery is a typical example included in the “unit cell” referred to herein, and an assembled battery module including a plurality of such unit cells is disclosed in the “group” disclosed herein. This is a typical example of a “battery module”.

It is a block diagram which shows the structure of the assembled battery module which concerns on one Embodiment. It is a perspective view showing typically an assembled battery concerning one embodiment. It is a figure which shows typically the circuit diagram of the assembled battery which concerns on one Embodiment. It is a figure which shows the control flow of the assembled battery module which concerns on one Embodiment. It is a perspective view which shows typically the assembled battery which concerns on other embodiment. It is a perspective view which shows typically the assembled battery which concerns on other embodiment.

  Embodiments according to the present invention will be described below with reference to the drawings. In the following drawings, members / parts having the same action are described with the same reference numerals. Note that the dimensional relationship (length, width, thickness, etc.) in each drawing does not reflect the actual dimensional relationship. Further, matters other than the matters specifically mentioned in the present specification and matters necessary for the implementation of the present invention (for example, general technology related to the construction and manufacturing method of the positive electrode and the negative electrode, secondary batteries and other batteries) Etc.) can be grasped as a design matter of those skilled in the art based on the prior art in this field. In addition, each drawing is drawn typically and does not necessarily reflect a real thing. Each drawing shows only an example, and each drawing does not limit the present invention unless otherwise specified.

  FIG. 1 is a block diagram showing a configuration of an assembled battery module 100 according to the present embodiment. The assembled battery module 100 switches between battery travel that travels using the power of the electric motor and battery-less travel that travels without using the power of the electric motor (for example, engine travel that travels using only the power of the engine). It is particularly preferably used as a power source for a motor (electric motor) mounted on a vehicle capable of driving, typically a hybrid vehicle, a vehicle equipped with an electric motor such as a plug-in hybrid vehicle. Although not intended to be particularly limited, the present invention will be described in detail below by taking as an example an assembled battery module 100 used as a motor power source mounted in a hybrid vehicle.

  The assembled battery module 100 includes an assembled battery 10, a load (not shown) connected to the assembled battery 10, and an electronic control unit (ECU) 80 that adjusts the operation of the load according to the state of the assembled battery 10. It can be a configuration. The load connected to the assembled battery 10 may include a power consumer that consumes the electric power stored in the assembled battery 10. The load may include a power supply device that supplies power that can charge the battery pack 10. In this embodiment, the load is an electric motor with a regeneration function. The electric motor receives electric power output from the assembled battery 10 and generates power (energy) for driving the vehicle. The assembled battery module 100 also includes a system main relay (SMR: not shown) that switches between an on state in which the assembled battery 10 and the load are connected and an off state in which the connection of the assembled battery 10 and the load is cut off. Yes. The ECU 80 is configured to run the vehicle using an electric motor when the SMR is turned on (battery running). In addition, an engine that outputs power used to travel the vehicle is provided outside the assembled battery module 100. The ECU 80 is configured to run the vehicle using the engine when the SMR is turned off (battery-less running). The battery running may be a mode of running using the power of both the electric motor and the engine.

  FIG. 2 is a perspective view schematically showing the configuration of the assembled battery 10 according to the present embodiment. FIG. 3 is a diagram schematically showing a circuit of the assembled battery 10. As shown in FIGS. 1 to 3, the assembled battery 10 disclosed herein is configured by electrically connecting a plurality of chargeable / dischargeable cells 20 in parallel. In this embodiment, the plurality of unit cells 20 is composed of a unit cell 20A group and a unit cell 20B group. In the illustrated example, a unit cell 20A group including three unit cells 20A having the same shape and a unit cell 20B group including three unit cells 20B having the same shape are arranged at a constant interval. The unit cells 20A constituting the unit cell 20A group are electrically connected in parallel. The unit cells 20B constituting the unit cell 20B group are electrically connected in parallel. The unit cell 20A group and the unit cell 20B group are electrically connected in series.

  The assembled battery 10 disclosed herein may be an assembled battery in which unit cells (typically, unit cells having a flat outer shape) 20 are electrically connected in parallel. Is not particularly limited. In this embodiment, a battery pack 10 is used in which a flat lithium ion secondary battery is a single battery 20 and a plurality of the single batteries 20 are connected in parallel.

Each of the plurality of unit cells 20 includes an electrode body (not shown), an electrolyte solution (not shown), and a battery case 30 that houses the electrode body and the electrolyte solution. The electrode body of this embodiment is configured by laminating a positive electrode and a negative electrode with a separator in the same manner as a unit cell provided in a typical assembled battery 10. The positive electrode may have a structure in which a positive electrode active material (for example, a lithium transition metal composite oxide such as LiNi _1/3 Co _1/3 Mn _1/3 O ₂ ) is held on a positive electrode current collector. The negative electrode may have a structure in which a negative electrode active material (for example, a carbon material) is held on a negative electrode current collector.

  The separator is a member that separates the positive electrode and the negative electrode. In this embodiment, the separator is made of a sheet material having a predetermined width having a plurality of minute holes. As the separator, a porous sheet made of a resin such as polyethylene (PE), polypropylene (PP), polyester, cellulose, or polyamide can be used. For example, a separator having a single layer structure or a separator having a laminated structure made of a porous polyolefin resin such as PE or PP can be suitably used.

The electrolytic solution typically exhibits a liquid state at normal temperature (for example, 25 ° C.), and preferably always exhibits a liquid state within a use temperature range (for example, −20 ° C. to 60 ° C.). As the electrolytic solution, a solution in which a supporting salt (for example, a lithium salt, a sodium salt, a magnesium salt, etc., or a lithium salt in a lithium ion secondary battery) is dissolved or dispersed in a nonaqueous solvent can be suitably used. As the supporting salt, the same salt as a general lithium ion secondary battery can be appropriately selected and adopted. For example, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , Li (CF ₃ SO ₂ ) ₂ N, Lithium salts such as LiCF ₃ SO ₃ can be used. Among these, LiPF ₆ can be preferably used. As the non-aqueous solvent, organic solvents such as various carbonates, ethers, esters, nitriles, sulfones, and lactones used in general lithium ion secondary batteries can be used without particular limitation. Specific examples include ethylene carbonate (EC), propylene carbonate (PC), diethyl carbonate (DEC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC).

  The material of the battery case 30 may be the same as that used in the conventional lithium ion secondary battery, and is not particularly limited. A battery case 30 mainly composed of a lightweight and highly heat conductive metal material is preferable, and aluminum or the like is exemplified as such a metal material. On the upper surface of the battery case 30, a positive terminal (positive side external terminal) 40 electrically connected to the positive electrode of the electrode body and a negative terminal (negative side external terminal) 42 electrically connected to the negative electrode are provided. Yes.

  Each single battery 20 constituting the assembled battery 10 includes a current interrupt device (CID) that is not shown. The current interruption mechanism is a mechanism that interrupts the current path when the pressure in the battery case becomes abnormally high. In this embodiment, the current interruption mechanism is constructed inside the positive terminal 40 so that the conduction path of the battery current in the positive electrode is interrupted. The current interrupting mechanism is configured to interrupt the electrical connection between the positive electrode and the positive electrode terminal 40 when the internal pressure of the battery case 30 becomes higher than a predetermined pressure. The current cut-off mechanism is not limited to the positive electrode side and may be provided on the negative electrode side as long as the conduction path can be cut off.

  When constructing the assembled battery 10, the unit cells 20 </ b> A constituting the group of unit cells 20 </ b> A are arranged with their directions aligned so that the positive terminals 40 and the negative terminals 42 are adjacent to each other. Then, between the adjacent single cells 20 </ b> A, the positive terminals 40 and the negative terminals 42 are electrically connected by the inter-terminal connector 44. Further, the unit cells 20B constituting the unit cell 20B group are arranged with their directions aligned so that the positive terminals 40 and the negative terminals 42 are adjacent to each other. And between each adjacent unit cell 20 </ b> B, the positive terminals 40 and the negative terminals 42 are electrically connected by the inter-terminal connector 44. The unit cells 20A constituting the unit cell 20A group and the unit cells 20B constituting the unit cell 20B group are arranged with their directions reversed so that the positive electrode terminal 40 and the negative electrode terminal 42 face each other. . One positive terminal 40 and the other negative terminal 42 are electrically connected by the inter-terminal connector 44 between the adjacent unit cells 20A and 20B. Thus, the unit cells 20A constituting the unit cell 20A group are connected in parallel, the unit cells 20B constituting the unit cell 20B group are connected in parallel, and the unit cell 20A group and the unit cell 20B group are connected in series. By connecting, the assembled battery 10 having a desired voltage is constructed.

  Here, in each single battery 20 constituting the assembled battery 10, for example, a foreign substance mixed in the single battery 20 may penetrate the separator and bridge between the positive and negative electrodes, thereby causing a minute internal short circuit. When such a minute internal short circuit occurs, the battery temperature gradually rises over several hours. At that time, a voltage drop occurs in the internally short-circuited cells. Therefore, when each cell 20 is connected in parallel, current flows from the other cell 20 connected in parallel to the internally short-circuited cell 20. Is assumed. Since such a sneak current (circulating current) flows in a concentrated manner at the short-circuited portion, if left as it is, the separator may be melted and contracted by Joule heat generation, which may increase the internal short circuit.

  In the assembled battery module 100 disclosed here, attention is paid to the circulating current that can be generated when the unit cells 20 are connected in parallel, and the unit cell 20 that is internally short-circuited so that the circulating current is cut off. By operating the current interruption mechanism, the expansion of the internal short circuit is suppressed.

  That is, the assembled battery module 100 disclosed herein detects that an internal short circuit has occurred in any of the plurality of single cells 20, and the temperature of the single short circuit cell 20 is equal to or lower than the melting point of the separator. In this case, after switching to battery-less running, the internal short-circuited unit cell 20 is heated to a temperature not lower than the boiling point of the electrolytic solution and not higher than the melting point of the separator, and control for operating the current interrupting mechanism is performed. Yes.

  The typical configuration of the ECU 80 includes at least a ROM (Read Only Memory) storing a program for performing such control, a CPU (Central Processing Unit) capable of executing the program, and temporarily storing data. A random access memory (RAM) and an input / output port (not shown) are included. A voltage sensor 50, a temperature sensor 70, and a heater 60 are attached to each single battery 20 constituting the assembled battery 10.

  The voltage sensor 50 is configured to detect the voltage of each single battery 20 constituting the assembled battery 10. The output signal of the voltage sensor 50 is input to the ECU 80 via the input port. The ECU 80 acquires information on the voltage of each unit cell 20 constituting the assembled battery 10 based on the output signal from the voltage sensor 50.

  The temperature sensor 70 is configured to detect the cell temperature of each single battery 20 constituting the assembled battery 10. The output signal of the temperature sensor 70 is input to the ECU 80 via the input port. The ECU 80 acquires information on the cell temperature of each unit cell 20 constituting the assembled battery 10 based on an output signal from the temperature sensor 70.

  The heater 60 is configured to heat the unit cell 20 that is internally short-circuited. In this embodiment, the heater 60 is disposed on the bottom surface of the assembled battery 10. The heater 60 is configured to heat the entire assembled battery 10 (all unit cells 20 constituting the assembled battery 10) including the internally short-circuited unit cells 20. The electric power for driving the heater 60 may be supplied from the assembled battery 10 or may be supplied from an external power source other than the assembled battery 10 (for example, a lead storage battery mounted on the assembled battery module 100). The heater 60 is electrically connected to the ECU 80. When the temperature of the unit cell 20 that is internally short-circuited is equal to or lower than the melting point of the separator, the ECU 80 transmits a command related to the heating control of the unit cell 20 to the heater 60. The heater 60 heats the internally short-circuited unit cell 20 to a predetermined cell temperature based on a command from the ECU 80.

  The heating temperature by the heater 60 can be set to a temperature equal to or higher than the boiling point of the electrolytic solution. By heating the internal short-circuited unit cell 20 to a temperature equal to or higher than the boiling point of the electrolytic solution, the electrolytic solution in the unit cell 20 volatilizes and the internal pressure of the battery case 30 increases. Thereby, a current interruption mechanism can be operated. Although it does not specifically limit, the boiling point of electrolyte solution may be 80 to 100 degreeC (typically 90 degreeC +/- 5 degreeC), for example. The boiling point of the electrolytic solution may be stored in advance in a storage unit such as a ROM. Moreover, the heating temperature by the heater 60 can be set to a temperature below the melting point of the separator. By setting the heating temperature by the heater 60 to be equal to or lower than the melting point of the separator, it is possible to suppress the melt shrinkage of the separator due to heating (and expansion of the internal short circuit). Although not particularly limited, the separator may have a melting point of, for example, 120 ° C. to 150 ° C. (typically 130 ° C. ± 10 ° C.). The melting point of such a separator may be stored in advance in a storage unit such as a ROM.

  Although the heating time by the heater 60 is not particularly limited, it may be a time until the current interruption mechanism of the unit cell 20 that is internally short-circuited can operate. In a preferred embodiment, the heating time by the heater 60 can be approximately 3 minutes to 800 minutes (eg, 5 minutes to 700 minutes, typically 10 minutes to 500 minutes). The heating time may be 30 minutes to 300 minutes, or may be 60 minutes to 100 minutes. Within such a heating time range, the current interrupting mechanism can be appropriately operated without damaging the unit cell 20. The electric power of the heater 60 may vary depending on the specific heat of the unit cell, but is preferably 3 W or more (for example, 3 W to 600 W), more preferably 5 W or more (for example, 5 W to 500 W), and even more preferably 10 W or more (for example, 10 W to 30 W). It is. If it is within the range of the electric power of such a heater 60, the current interruption mechanism can be operated in a shorter time.

The method for detecting the internal short circuit is not particularly limited. For example, when an internal short circuit occurs, a voltage drop occurs in the cell 20. Therefore, the ECU 80 can determine whether or not an internal short circuit has occurred in the single battery 20 from the information on the voltage of each single battery 20 detected by the voltage sensor 50. Specifically, when at least one of the following conditions (A) to (C) is satisfied, it can be determined that an internal short circuit has occurred in the unit cell.
(A) In a state where charging / discharging is not performed, a voltage drop of a predetermined value (for example, 0.2 V / h per hour) or more occurs in the unit cell.
(B) The unit cell continues a voltage state of a predetermined value (for example, 3.0 V) or less for a predetermined time (for example, 1 second) or longer.
(C) The voltage of the unit cell is lower by a predetermined value (for example, 0.3 V) or more than the other unit cell group not connected in parallel with the unit cell.

  Alternatively, the ECU 80 may detect an internal short circuit based on information on the cell temperature of the single battery 20. That is, when an internal short circuit occurs, the unit cell 20 generates heat. Therefore, the ECU 80 can determine whether or not an internal short circuit has occurred in each cell 20 based on the cell temperature information of each cell 20 detected by the temperature sensor 70. You may perform combining the detection based on this temperature information, and the detection based on the voltage information mentioned above. Thereby, the cell 20 short-circuited internally can be detected with higher accuracy.

  Operation | movement of the control apparatus 1 comprised in this way is demonstrated referring FIGS. 1-4. FIG. 4 is a flowchart showing a processing routine executed by the ECU 80 of the assembled battery module 100. This routine is executed when it is detected that an internal short circuit has occurred in any of the unit cells 20 constituting the assembled battery 10 (step S10).

  When the ECU 80 detects that an internal short circuit has occurred in any of the unit cells 20 in step S10, the ECU 80 first switches to battery-less travel (step S20). For example, the above-described SMR may be turned off to switch to battery-less running using only engine power.

  Next, in step S30, the ECU 80 determines from the cell temperature information detected by the temperature sensor 70 whether or not the cell temperature of the unit cell 20 in which the internal short circuit has occurred is equal to or lower than the melting point of the separator. The ECU 80 determines that it is not necessary to perform the heating process when the temperature of the internally short-circuited unit cell 20 exceeds the melting point of the separator (NO), and ends this processing routine. On the other hand, when the temperature of the unit cell 20 that is internally short-circuited is equal to or lower than the melting point of the separator (YES), it is determined that heat treatment is necessary, and the process proceeds to the next step S40.

  In step S <b> 40, the ECU 80 transmits a command regarding heating of the unit cell 20 to the heater 60. This command includes information on the heating temperature of the unit cell 20 described above. That is, the ECU 80 drives and controls the heater 60 so that the internal short-circuited unit cell 20 is heated to a temperature not lower than the boiling point of the electrolytic solution and not higher than the melting point of the separator. In this way, by driving and controlling the heater 60, the internally short-circuited unit cell 20 is heated to a temperature not lower than the boiling point of the electrolyte and not higher than the melting point of the separator, whereby the electrolyte in the unit cell 20 is volatilized and the battery case 30. The internal pressure increases.

  Next, in step S50, the ECU 80 determines whether or not the current interruption mechanism of the unit cell 20 that has been internally short-circuited has been activated. If the current interrupt mechanism is not operating (NO), the process returns to step S40, and the heating process for the internally short-circuited unit cell 20 is continued. On the other hand, when the current interruption mechanism is activated (YES), the process proceeds to step S60, and the heating process of the unit cell 20 that is internally short-circuited is stopped. The assembled battery module 100 may include a cooling mechanism that cools the internally short-circuited unit cell 20 as necessary. ECU80 may transmit the command for cooling the cell 20 which carried out the internal short circuit to a cooling mechanism, after stopping the said heat processing. Thereby, after the operation of the current interrupting mechanism, it is possible to suppress the unit cell 20 from generating heat and exceeding the melting point of the separator (as a result, the separator is thermally contracted and the internal short circuit is expanded).

  According to the above embodiment, when an internal short circuit occurs in any of the unit cells 20 constituting the assembled battery 10, the internally shorted unit cell is heated to a temperature not lower than the boiling point of the electrolyte and not higher than the melting point of the separator. By operating the current interrupting mechanism, it is possible to suppress an event (circulating current) in which current flows from another unit cell 20 to the unit cell 20 that is internally short-circuited. For this reason, it is difficult for the separator to melt and shrink due to the circulating current, and the expansion of the internal short circuit can be suppressed.

  Hereinafter, although the test example regarding this invention is demonstrated, it is not intending to limit this invention to what is shown to the following test examples.

Positive and negative electrode sheets each holding a positive electrode active material and a negative electrode active material on a sheet-like positive electrode current collector and a negative electrode current collector, respectively, are wound through a separator and housed in a case together with an electrolyte. A battery pack was constructed by electrically connecting lithium ion secondary batteries in parallel. As the separator, a porous sheet having a three-layer structure of polypropylene (PP) / polyethylene (PE) / polypropylene (PP) was used. As an electrolytic solution, a mixed solvent containing ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC) in a volume ratio of 30:40:30, and LiPF ₆ as a supporting salt is about 1 mol / liter. What was contained in the density | concentration of was used. Moreover, the electric current interruption mechanism (CID) was installed in the positive electrode side of each lithium ion secondary battery. The capacity of each lithium ion secondary battery was 25 Ah. The melting point of the separator is 130 ° C., and the boiling point of the electrolytic solution is 90 ° C.

  A short circuit test was performed on the assembled battery. In the short-circuit test, after adjusting the voltage of each unit cell to 4.1 V in a temperature environment of 25 ° C., a single nail (diameter 3 mm, The tip angle was 30 degrees). Moreover, after heating the assembled battery after the said short circuit test to a predetermined temperature and heating it, the heating test which hold | maintains at that temperature for 15 minutes was done. Here, the heating test was carried out by varying the heating temperature, the heater power, and the time required for heating (Examples 1 to 6). Table 1 summarizes the heating temperature, heater power, and heating time in each example.

  After the heating test, the assembled battery of each example was allowed to cool at room temperature for 24 hours, and the presence or absence of CID operation was confirmed. Moreover, the voltage (residual voltage) of the cell short-circuited internally was measured. The cell in which the CID was activated disassembled the battery case and measured the residual voltage with the internal terminal. The results are shown in Table 1. Here, it is suggested that the expansion of the internal short circuit is suppressed as the residual voltage is higher.

  As shown in Table 1, in Examples 1 to 4, the heating temperature in the heating test is set to be equal to or higher than the boiling point of the electrolytic solution and equal to or lower than the melting point of the separator. In Examples 1 to 4, the CID was appropriately operated in the heating test. Also, good results were obtained for the residual voltage. On the other hand, in Example 5 in which the heating temperature was lower than the boiling point of the electrolytic solution, the residual voltage was lower than in Examples 1 to 4. In Example 5, the CID does not operate because the heating temperature is low, and it is assumed that the short circuit portion is heated by the circulating current and the short circuit is expanded. Further, in Example 6 in which the heating temperature exceeded the melting point of the separator, although the CID was activated during the heating test, a decrease in the residual voltage was observed. In Example 6, since the heating temperature was too high, it is presumed that the separator melted and contracted by heating and the internal short circuit expanded. From this result, it was confirmed that the expansion of the internal short circuit can be suppressed by heating the internal short-circuited cell to a temperature not lower than the boiling point of the electrolyte and not higher than the melting point of the separator and operating the current interrupt mechanism.

  As mentioned above, although the specific example of this invention was demonstrated in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

For example, in the above-described embodiment, the case where the heater 60 is installed on the bottom surface of the assembled battery 10 to heat the entire assembled battery 10 including the internally short-circuited unit cell is illustrated. It is not limited to this. For example, as shown in FIG. 5, an independent heater 60 may be installed on the bottom surface of each unit cell 20 constituting the assembled battery 10. In this case, since only the unit cell 20 that has been internally short-circuited can be heated, damage due to heating of other unit cells can be suppressed.
Alternatively, as shown in FIG. 6, an independent heater 60 is installed on the bottom surface of each of the unit cells 20 </ b> A and unit cells 20 </ b> B, and the entire unit cell group connected in parallel with the internally short-circuited unit cell 20. You may comprise so that it may heat. Even in such a case, the above-described effects can be obtained.

10 assembled battery 20 single cell 30 battery case 40 positive terminal 42 negative terminal 44 inter-terminal connector 50 voltage sensor 60 heater 70 temperature sensor 80 ECU
100 battery module

Claims (1)

A method for controlling an assembled battery module mounted on a vehicle capable of switching between battery travel that travels using the power of an electric motor and battery-less travel that travels without using the power of the electric motor,
The assembled battery module is configured by electrically connecting a plurality of single cells in parallel.
Each of the plurality of unit cells is
An electrode body configured by laminating a positive electrode and a negative electrode via a separator;
An electrolyte,
A battery case containing the electrode body and the electrolyte;
An external terminal provided in the battery case and electrically connected to the electrode body;
When the internal pressure of the battery case becomes higher than a predetermined pressure, the battery case includes a current interrupting mechanism that interrupts electrical connection between the electrode body and the external terminal,
Here, when it is detected that an internal short circuit has occurred in any of the plurality of single cells, and the temperature of the single short circuited cell is equal to or lower than the melting point of the separator, the battery-less travel is switched. A method for controlling an assembled battery module, wherein control is performed to heat the internal short-circuited cell to a temperature not lower than the boiling point of the electrolytic solution and not higher than the melting point of the separator to activate the current interrupting mechanism.

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