JP6663572B2 - Control method of battery module - Google Patents

Description

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

  A lithium ion secondary battery, a nickel-metal hydride battery, other secondary batteries, or a storage battery such as a capacitor, which is lightweight and has a high energy density, is a unit cell, and a battery pack formed by connecting a plurality of the unit cells can provide high output. As the power source, it is preferably used as a vehicle-mounted power source or a power source for personal computers and portable terminals. For example, as an example of a vehicle-mounted battery pack, Patent Document 1 discloses a power storage system configured by arranging a plurality of unit cells and connecting the unit cells in parallel.

JP 2014-117021A

By the way, in each of the cells constituting the assembled battery, for example, a minute internal short-circuit may occur when foreign matter mixed in the cell penetrates through the separator and bridges between the positive and negative electrodes. At the time of such a short-circuit, a voltage drop occurs in the unit cell. Therefore, when each unit cell is connected in parallel, it is assumed that current flows from the other unit cell connected in parallel to the unit cell internally short-circuited. Since such a sneak current (circulating current) flows intensively at a short-circuited portion, if left as it is, the separator may melt and shrink due to Joule heat, which may be a factor that causes an internal short-circuit to expand. Therefore, a technique for suppressing the circulating current is required.
The present invention has been made in view of such a point, and a main object of the present invention is to provide an assembled battery module in which a plurality of single cells are electrically connected in parallel to each other to suppress a circulating current. The purpose 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 running using the power of an electric motor and batteryless travel running without using the power of the electric motor. Is a control method. The assembled battery module is configured such that a plurality of cells are electrically connected in parallel. Each of the plurality of cells is provided in an electrode body in which a positive electrode and a negative electrode are stacked with a separator interposed therebetween, an electrolytic solution, a battery case containing the electrode body and the electrolytic solution, and provided in the battery case. An external terminal electrically connected to the electrode body, and a current cutoff mechanism for interrupting an electrical connection between the electrode body and the external terminal when an internal pressure of the battery case becomes higher than a predetermined pressure. And The control method detects that an internal short circuit has occurred in any of the plurality of cells, and, when the temperature of the internally short-circuited cell is equal to or lower than the melting point of the separator, the battery-less traveling is performed. After the switching, the internal short-circuited cell is heated to a temperature equal to or higher than the boiling point of the electrolytic solution and equal to or lower than the melting point of the separator to control the current cutoff mechanism to operate. According to such a configuration, the circulating current can be effectively suppressed.

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

It is a block diagram showing composition of an assembled battery module concerning one embodiment. It is a perspective view showing typically the battery pack concerning one embodiment. It is a figure showing typically the circuit diagram of the battery pack concerning one embodiment. It is a figure showing the control flow of the battery pack module concerning one embodiment. It is a perspective view showing typically the battery pack concerning other embodiments. It is a perspective view showing typically the battery pack concerning other embodiments.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, members and portions having the same function are described with the same reference numerals. The dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect the actual dimensional relationships. In addition, matters other than those specifically mentioned in the present specification and which are necessary for carrying out the present invention (for example, the structure and manufacturing method of the positive electrode and the negative electrode, general techniques related to the construction of secondary batteries and other batteries) ) Can be understood as a design matter of a person skilled in the art based on the prior art in the field. In addition, each drawing is schematically drawn and does not necessarily reflect the real thing. In addition, each drawing is merely an example, and each drawing does not limit the present invention unless otherwise specified.

  FIG. 1 is a block diagram showing a configuration of the battery pack module 100 according to the present embodiment. The battery pack module 100 switches between battery running, which runs using the power of the electric motor, and batteryless running, which runs without using the power of the electric motor (for example, engine running, which runs using only the power of the engine). It is particularly suitably used as a power source for a motor (electric motor) mounted on a vehicle capable of performing the above-mentioned operations, typically a hybrid vehicle, a vehicle equipped with a motor such as a plug-in hybrid vehicle. Although not intended to be particularly limited, the present invention will be described in detail below with reference to an assembled battery module 100 used as a power supply for a motor mounted on a hybrid vehicle.

  The assembled battery module 100 includes the 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 battery pack 10 may include a power consuming device that consumes the power stored in the battery pack 10. The load may include a power supply that supplies power capable of charging the battery pack 10. In this embodiment, the load is an electric motor with a regenerative function. The electric motor receives power output from the battery pack 10 and generates power (energy) for driving the vehicle. Further, the battery pack module 100 includes a system main relay (SMR: not shown) that switches between an on state in which the battery pack 10 and the load are connected and an off state in which the battery pack 10 and the load are disconnected. I have. The ECU 80 runs the vehicle using the electric motor when the SMR is turned on (battery running). An engine that outputs power used for running the vehicle is provided outside the battery module 100. When the SMR is turned off, the ECU 80 causes the vehicle to run using the engine (battery-less running). The battery traveling may be a mode in which the vehicle travels using the power of both the electric motor and the engine.

  FIG. 2 is a perspective view schematically illustrating the configuration of the battery pack 10 according to the present embodiment. FIG. 3 is a diagram schematically illustrating a circuit of the battery pack 10. As shown in FIGS. 1 to 3, the battery pack 10 disclosed here is configured such that a plurality of chargeable / dischargeable cells 20 are electrically connected in parallel. In this embodiment, the plurality of unit cells 20 include a group of unit cells 20A and a group of unit cells 20B. In the illustrated example, a unit cell group 20A including three unit cells 20A having the same shape and a unit cell group 20B including three unit cells 20B having the same shape are arranged at regular intervals. The single cells 20A constituting the single 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 cells 20A and the unit cells 20B are electrically connected in series.

  The battery pack 10 disclosed herein may be a battery pack 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 flat-shaped lithium ion secondary battery is used as a unit cell 20, and an assembled battery 10 in which a plurality of the unit cells 20 are connected in parallel is employed.

Each of the plurality of unit cells 20 includes an electrode body (not shown), an electrolytic solution (not shown), and a battery case 30 that accommodates the electrode body and the electrolytic solution. The electrode body of the present embodiment is configured by laminating a positive electrode and a negative electrode with a separator interposed therebetween, similarly to 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 formed of a sheet material having a predetermined width and 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-based 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 obtained by dissolving or dispersing a supporting salt (for example, a lithium salt, a sodium salt, a magnesium salt, or the like; a lithium salt in a lithium ion secondary battery) in a nonaqueous solvent can be suitably used. As the supporting salt, one similar to a general lithium ion secondary battery can be appropriately selected and employed. For example, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , Li (CF ₃ SO ₂ ) ₂ N, A lithium salt such as LiCF ₃ SO ₃ can be used. Among them, LiPF ₆ can be suitably used. As the non-aqueous solvent, various kinds of organic solvents such as carbonates, ethers, esters, nitriles, sulfones, and lactones used in general lithium ion secondary batteries can be used without any 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 metal material that is lightweight and has good thermal conductivity 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 (external terminal on the positive side) 40 electrically connected to the positive electrode of the electrode body and a negative terminal (external terminal on the negative side) 42 electrically connected to the negative electrode are provided. I have.

  Each of the cells 20 constituting the battery pack 10 has a current interrupt mechanism (CID: Current Interrupt Device) not shown. The current interrupt mechanism is a mechanism that interrupts the current path when the pressure in the battery case becomes abnormally high. In this embodiment, the current cutoff mechanism is constructed inside the positive electrode terminal 40 so that the conduction path of the battery current in the positive electrode is cut off. 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 interrupting mechanism is only required to interrupt the conduction path, and may be provided not only on the positive electrode side but also on the negative electrode side.

  When constructing the assembled battery 10, the unit cells 20A constituting the unit cell 20A group are arranged in the same direction so that the respective positive electrode terminals 40 and the respective negative electrode terminals 42 are arranged adjacent to each other. Then, the positive terminals 40 and the negative terminals 42 are electrically connected by the inter-terminal connector 44 between the adjacent unit cells 20A. In addition, the unit cells 20B constituting the unit cell 20B group are arranged in the same direction so that the respective positive terminals 40 and the respective negative terminals 42 are disposed adjacent to each other. Then, the positive terminals 40 and the negative terminals 42 are electrically connected by the inter-terminal connector 44 between the adjacent unit cells 20B. In addition, the unit cells 20A forming the unit cells 20A and the unit cells 20B forming the unit cells 20B group are arranged with their directions inverted so that the positive electrode terminal 40 and the negative electrode terminal 42 face each other. . The one positive electrode terminal 40 and the other negative electrode terminal 42 are electrically connected between the adjacent unit cells 20A and 20B by the inter-terminal connector 44. In this manner, 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 of a desired voltage is constructed.

  Here, in each of the cells 20 constituting the assembled battery 10, for example, a minute internal short circuit may occur when foreign matter mixed in the cell 20 penetrates through the separator and bridges between the positive and negative electrodes. When such a small internal short circuit occurs, the battery temperature gradually increases over several hours. At this time, since a voltage drop occurs in the unit cell 20 that is internally short-circuited, if each unit cell 20 is connected in parallel, current flows from another cell unit 20 connected in parallel to the unit cell 20 that is internally short-circuited. Is assumed. Since such a sneak current (circulating current) flows intensively at a short-circuited portion, if left as it is, the separator may melt and shrink due to Joule heat, which may be a factor that causes an internal short-circuit to expand.

  In the assembled battery module 100 disclosed herein, attention is paid to a circulating current that may be generated when such cells 20 are connected in parallel, and the short-circuit of the cells 20 that is internally short-circuited such that the circulating current is interrupted. By operating the current cutoff mechanism, the internal short circuit is prevented from expanding.

  That is, the assembled battery module 100 disclosed herein detects that an internal short circuit has occurred in any of the plurality of cells 20 and the temperature of the internally short-circuited 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 cell 20 is heated to a temperature equal to or higher than the boiling point of the electrolytic solution and equal to or lower than the melting point of the separator to control the current interrupting mechanism to operate. I have.

  A 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. It includes a random access memory (RAM) and an input / output port (not shown). A voltage sensor 50, a temperature sensor 70, and a heater 60 are attached to each of the cells 20 constituting the assembled battery 10.

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

  The temperature sensor 70 is configured to detect a cell temperature of each of the cells 20 constituting the assembled battery 10. An output signal of the temperature sensor 70 is input to the ECU 80 via an input port. Then, the ECU 80 acquires information on the cell temperature of each of the cells 20 constituting the battery pack 10 based on the output signal from the temperature sensor 70.

  The heater 60 is configured to heat the unit cell 20 that has been internally short-circuited. In this embodiment, the heater 60 is arranged on the bottom surface of the battery pack 10. The heater 60 is configured to heat the entire assembled battery 10 including the unit cells 20 that are internally short-circuited (all the unit cells 20 constituting the assembled battery 10). The power for driving the heater 60 may be supplied from the battery pack 10 or may be supplied from an external power source other than the battery pack 10 (for example, a lead storage battery mounted on the battery pack 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 heating control of the unit cell 20 to the heater 60. The heater 60 heats the unit cell 20 that has been internally short-circuited 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 unit cell 20 that has been internally short-circuited 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, the current interruption mechanism can be operated. Although not particularly limited, the boiling point of the electrolytic solution may be, for example, 80 ° C to 100 ° C (typically 90 ° C ± 5 ° C). The boiling point of the electrolytic solution may be stored in a storage unit such as a ROM in advance. The heating temperature by the heater 60 can be set to a temperature equal to or lower than 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 melting shrinkage of the separator due to the heating (and, consequently, the expansion of the internal short circuit). Although not particularly limited, the melting point of the separator may be, for example, 120C to 150C (typically 130C10C). The melting point of the separator may be stored in a storage unit such as a ROM in advance.

  The heating time by the heater 60 is not particularly limited, but may be any time as long as the current interruption mechanism of the cell 20 that has been internally short-circuited can operate. In a preferred embodiment, the heating time by the heater 60 may 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. When the heating time is within the above range, the current cutoff mechanism can be appropriately operated without damaging the cell 20. The 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 still more preferably 10 W or more (for example, 10 W to 30 W). It is. When the electric power of the heater 60 is within such a range, the current cutoff mechanism can be operated in a shorter time.

The method for detecting an 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 cell 20 based on the information on the voltage of each cell 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 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 cell keeps a voltage state equal to or lower than a predetermined value (for example, 3.0 V) for a predetermined time (for example, 1 second) or more.
(C) The voltage of the unit cell is lower by a predetermined value (for example, 0.3 V) or more than other unit cells 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 of the cells 20 based on the information on the cell temperature of each of the cells 20 detected by the temperature sensor 70. The detection based on the temperature information and the detection based on the voltage information described above may be performed in combination. This makes it possible to detect the short-circuited cell 20 with higher accuracy.

  The operation of the control device 1 configured as described above will be described with reference to FIGS. FIG. 4 is a flowchart showing a processing routine executed by ECU 80 of battery pack module 100. This routine is executed when it is detected that an internal short circuit has occurred in any of the cells 20 constituting the battery pack 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 running (step S20). For example, the SMR may be turned off to switch to battery-less traveling using only the power of the engine.

  Next, in step S30, the ECU 80 determines from the information on the cell temperature 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. If the temperature of the unit cell 20 that has been internally short-circuited exceeds the melting point of the separator (NO), the ECU 80 determines that it is not necessary to perform the heating process, and ends this processing routine. On the other hand, if the temperature of the unit cell 20 that has been internally short-circuited is equal to or lower than the melting point of the separator (YES), it is determined that the heating process needs to be performed, and the process proceeds to the next step S40.

  In step S40, ECU 80 transmits a command relating to heating of unit cell 20 to heater 60. This command includes information on the heating temperature of the unit cell 20 described above. That is, the ECU 80 controls the driving of the heater 60 so that the unit cell 20 that has been internally short-circuited is heated to a temperature equal to or higher than the boiling point of the electrolytic solution and equal to or lower than the melting point of the separator. By driving and controlling the heater 60 in this manner, the internally short-circuited single cell 20 is heated to a temperature equal to or higher than the boiling point of the electrolytic solution and equal to or lower than the melting point of the separator. Internal pressure rises.

  Next, in step S50, the ECU 80 determines whether or not the current cutoff mechanism of the unit cell 20 that has been internally short-circuited has been activated. If the current cutoff mechanism is not operating (NO), the process returns to step S40 to continue the heating process for the unit cell 20 that has been internally short-circuited. On the other hand, if the current cutoff mechanism has been activated (YES), the process proceeds to step S60, and the heating process of the short-circuited cell 20 is stopped. The battery module 100 may include a cooling mechanism for cooling the unit cells 20 that have been internally short-circuited, if necessary. After stopping the heating process, the ECU 80 may send a command to cool the unit cell 20 that has been internally short-circuited to the cooling mechanism. Thus, it is possible to prevent the unit cell 20 from generating heat and exceeding the melting point of the separator after the operation of the current cutoff mechanism (therefore, the separator is thermally contracted and the internal short circuit is expanded).

  According to the above-described embodiment, when an internal short circuit occurs in any of the cells 20 constituting the assembled battery 10, the internally short-circuited cell is heated to a temperature equal to or higher than the boiling point of the electrolyte and equal to or lower than the melting point of the separator. By operating the current interruption mechanism in this manner, an event (circulating current) in which current flows from another cell 20 to the cell 20 that has been internally short-circuited can be suppressed. For this reason, a situation in which the separator is melted and contracted due to the circulating current is unlikely to occur, and it is possible to suppress the expansion of the internal short circuit.

  Hereinafter, test examples according to the present invention will be described, but the present invention is not intended to be limited to those shown in the following test examples.

Positive and negative electrode sheets holding a positive electrode active material and a negative electrode active material respectively on a sheet-like positive electrode current collector and a negative electrode current collector are wound through a separator, and are 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 at about 1 mol / liter. Used at a concentration of. In addition, a current interruption mechanism (CID) was installed on 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 above assembled battery. In the short-circuit test, under a temperature environment of 25 ° C., the voltage of each cell was adjusted to 4.1 V, and then a stainless steel nail (diameter 3 mm, (Tip angle 30 degrees). Further, a heating test was performed in which a heater was wound around the assembled battery after the short-circuit test and the battery was heated to a predetermined temperature, and then maintained at that temperature for 15 minutes. Here, the heating test was performed by changing the conditions of the heating temperature, the power of the heater, and the time required for the temperature rise (Examples 1 to 6). Table 1 summarizes the heating temperature, heater power, and heating time in each example.

  After the heating test, the assembled batteries of each example were allowed to cool at room temperature for 24 hours, and it was confirmed whether or not the CID was activated. Further, the voltage (remaining voltage) of the unit cell that was internally short-circuited was measured. For the unit cell in which the CID was activated, the battery case was disassembled, and the residual voltage was measured using the internal terminal. Table 1 shows the results. Here, it is suggested that the higher the residual voltage, the more the expansion of the internal short circuit was suppressed.

  As shown in Table 1, in Examples 1 to 4, the heating temperature in the heating test was 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 operated properly in the heating test. Good results were also 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, it is assumed that the CID did not operate because the heating temperature was low, and the short circuit was heated by the circulating current, and the short circuit was enlarged. In Example 6, in which the heating temperature was higher than the melting point of the separator, the CID was activated during the heating test, but 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 due to the heating, and the internal short circuit was enlarged. From these results, it was confirmed that the expansion of the internal short-circuit can be suppressed by heating the internal short-circuited cell to a temperature equal to or higher than the boiling point of the electrolytic solution and equal to or lower than the melting point of the separator to operate the current interrupting 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 single battery is exemplified. 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 of the cells 20 constituting the battery pack 10. In this case, since only the unit cell 20 that is 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 20A and the unit cells 20B, and the entire unit group connected in parallel to the unit cells 20 that are internally short-circuited. You may comprise so that it may heat. Even in such a case, the above-described effects can be obtained.

DESCRIPTION OF SYMBOLS 10 Assembled battery 20 Single cell 30 Battery case 40 Positive terminal 42 Negative terminal 44 Connector between terminals 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 traveling running using the power of an electric motor and batteryless traveling traveling without using the power of the electric motor,
The assembled battery module is configured such that a plurality of cells are electrically connected in parallel,
Each of the plurality of cells is
An electrode body configured by stacking a positive electrode and a negative electrode with a separator interposed therebetween,
An electrolyte,
A battery case containing the electrode body and the electrolytic solution;
An external terminal provided on 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 cutoff mechanism that cuts off electrical connection between the electrode body and the external terminal,
Here, it is detected that an internal short circuit has occurred in any of the plurality of cells, and when the temperature of the internally short-circuited cell is equal to or lower than the melting point of the separator, the mode is switched to the battery-less running. A method of controlling the battery module, wherein the internal short-circuited cell is heated to a temperature equal to or higher than the boiling point of the electrolytic solution and equal to or lower than the melting point of the separator to operate the current interrupt mechanism.

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