JP5046018B2 - Battery pack and battery pack control system - Google Patents

Description

  The present invention relates to an assembled battery and a control system for the assembled battery.

  Lithium-ion batteries, nickel-metal hydride batteries and other secondary batteries or capacitors and other storage elements are used as unit cells, and a battery pack formed by connecting a plurality of unit cells in series is used as a power source for vehicle mounting, It is becoming increasingly important as a power source for personal computers and mobile terminals. In particular, an assembled battery in which a plurality of lithium-ion batteries that are lightweight and have a high energy density are connected in series as single cells is expected to be preferably used as a high-output power source for mounting on vehicles.

  In an assembled battery composed of a plurality of unit cells of this type, it is assumed that abnormal heat generation occurs in the unit cell due to overcharge, overdischarge, or the like. In order to monitor the heat generation of such single cells, a control system has been proposed as a prior art that controls the temperature of each single cell using a temperature sensor and shuts off the input / output of the assembled battery when the temperature rises abnormally. .

For example, in Patent Document 1, a heat-sensitive body having a heat-soluble member interposed between parallel conductive wires is commonly provided for a plurality of unit cells (single cells), and the heat-soluble member is caused by an abnormal temperature rise. A battery pack (assembled battery) is disclosed in which a thermal abnormality is detected by short-circuiting parallel conductive wires when the battery melts.
JP 2005-346944 A

  However, in the abnormality detection means of the above-mentioned Patent Document 1, a plurality of single cells are managed in common by one heat sensitive body, and abnormality of the assembled battery is detected only by ON / OFF of a signal due to a short circuit of the sensing line. For this reason, it has been difficult to accurately identify in which unit cell the thermal abnormality has occurred. For this reason, in order to accurately identify a unit cell that is abnormal in heat, it is necessary to collect and disassemble the assembled battery in which the abnormality is detected and analyze each unit cell in detail, and such disassembly and analysis work is extremely troublesome. won. In order to identify the unit cell in which the thermal abnormality has occurred, it may be necessary to provide a temperature sensor for each unit cell individually. Therefore, the configuration of the assembled battery becomes complicated and the cost for it becomes enormous.

  The present invention has been made in view of such a point, and a main object thereof is to provide an assembled battery control system capable of detecting a unit cell in which a thermal abnormality has occurred with a simple configuration, and an assembled battery constituting the system. That is.

  An assembled battery control system provided by the present invention includes an assembled battery in which a plurality of single cells each having a metal container are connected in series, and a controller electrically connected to the assembled battery. Control system. Furthermore, it is a system that detects a unit cell in which a thermal abnormality has occurred from an assembled battery.

  The battery pack control system of the present invention includes a metal wire wired over each of the unit cells connected in series and attached to each of the unit cell containers, and between each of the unit cell containers and the metal wire. And an insulating member that insulates the unit cell container from the metal wire. The metal wire is electrically connected to the control device. Here, when a thermal abnormality occurs in the unit cell constituting the assembled battery, the metal wire and the unit cell container with the thermal abnormality are brought into contact with melting or shrinking of the insulating member due to the heat. ing. And the said control apparatus is comprised so that the voltage applied to the said metal wire by the said contact may be measured, and the cell which the said thermal abnormality generate | occur | produced based on the measured value of the said voltage.

  In the present specification, the “unit cell” is a term indicating individual storage elements that can be connected in series with each other to form an assembled battery, and batteries, capacitors (physical batteries) having various compositions unless otherwise specified. ). The power storage element constituting the lithium ion battery is a typical example included in the “unit cell” referred to herein, and a lithium ion battery module (battery pack) including a plurality of such unit cells is disclosed herein. This is a typical example of an “assembled battery”. Moreover, what includes such an “assembled battery” and a control device composed of various electronic components connected to the assembled battery for control is referred to as an “assembled battery control system” in this specification.

  According to the battery pack control system having such a configuration, the battery cells are connected in series across the unit cells connected in series (that is, in order from one unit cell to another unit cell in a predetermined order not limited to the series order). ) With a simple configuration in which metal wires are wired, it is possible to accurately identify a unit cell in which a thermal abnormality such as overheating has occurred. Therefore, it is not necessary to install an independent sensor (for example, a temperature sensor) for each unit cell, and the assembled battery control system can be simplified. As a result, the cost of the assembled battery itself for constructing such an assembled battery control system can also be reduced.

  Accordingly, the present invention provides an assembled battery that achieves the above object. That is, the assembled battery for constructing the assembled battery control system of the present invention is configured by connecting a plurality of unit cells including a metal container in series, and straddling each unit cell connected in series. In other words, the metal wires (that is, the control device described above) wired to each of the unit cell containers are wired (in order from one unit cell to another unit cell in a predetermined order not limited to the series order). And an insulating member that is interposed between each of the unit cell containers and the metal wire, and insulates the unit cell container from the metal line. Here, when a thermal abnormality occurs in any of the unit cells, the metal wire and the unit cell container that has caused the thermal abnormality are brought into contact with the melting or contraction of the insulating member due to the heat. It is characterized by that.

  In a preferable aspect of the battery pack control system disclosed herein, the metal wire is attached to each of the unit cell containers in the order in which the unit cells are connected in series. According to such a configuration, it is only necessary to wire the metal wires according to the connection order of the unit cells, and the wiring work of the metal wires is simplified.

  In a preferred aspect of the assembled battery control system disclosed herein, the control device is configured to perform control to stop energization of the assembled battery when the abnormal battery is detected. According to such a configuration, it is possible to provide a battery pack with excellent safety that can quickly stop the charge / discharge control of the assembled battery when the battery is abnormal.

  Moreover, in a preferable one aspect | mode of the assembled battery control system disclosed here and the assembled battery for constructing | assembling the said system, the said insulating member is comprised with the thermoplastic resin whose softening point is 120 degrees C or less. Preferably, the insulating member is a covering material that covers the unit cell container and / or the metal wire.

  By using such a resin material that softens at a low temperature (and solubilizes at a relatively low temperature range), the cell container and the metal wire can be contacted quickly and reliably during abnormal overheating. . Moreover, by using as a covering material for the unit cell container, the insulating member can be used as an exterior material for preventing an electric shock in a normal state. Alternatively, when used as a coating material for a metal wire, there is an advantage that the metal wire can be protected because the metal wire is not exposed to the outside.

  In a preferred aspect of the assembled battery control system disclosed herein and the assembled battery for constructing the system, the metal wire is urged in a direction in contact with the unit cell container via the insulating member. It is attached in the state.

  With such an urging force, the metal wire and the unit cell container can be reliably brought into contact with each other when the insulating member is melted or contracted.

  In addition, it is preferable that the said metal wire is attached so that it may run over the outer surface of the said cell container (namely, extending and extending).

  By applying an appropriate tension in this manner and causing the metal wire to wrap around the single cell container, the metal wire is brought into close contact with the single cell container via the insulating member, and an urging force in the contacting direction is easily obtained. be able to. Moreover, the metal wire can be stably fixed to the unit cell container by the tension, and it is not necessary to use another fixing member for fixing the metal wire.

  In a preferable aspect of the assembled battery control system disclosed herein, the control device includes a storage unit that stores position information of the unit cell having the thermal abnormality. More preferably, a display unit for displaying position information of the unit cell having the thermal abnormality is provided.

  By storing the location information in the storage unit, when collecting or repairing an abnormal assembled battery, the operator reads the location information stored in the storage unit and causes a thermal abnormality from the target assembled battery. It is possible to easily specify the single cell. For this reason, the repair work of an assembled battery can be performed efficiently, for example. Further, by displaying the position information on the display unit, the worker can visually confirm (grasp) the position visually.

  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. In addition, this invention is not limited to the following embodiment. In addition, the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect actual dimensional relationships.

  The configuration of the assembled battery control system 100 of this embodiment will be described with reference to FIG. FIG. 1 is an external perspective view schematically showing the configuration of the assembled battery control system 100.

  The assembled battery control system 100 according to the present embodiment monitors thermal abnormalities of the unit cells 20 constituting the assembled battery 10 (for example, heat generation due to the presence of defective unit cells or malfunction due to failure of the charging device). Each cell is managed, and control is performed to shut off the input / output of the battery pack when the temperature rises abnormally. Roughly speaking, the assembled battery control system 100 includes an assembled battery 10, a metal wire 60, an insulating member 70, and a control device 30.

  The assembled battery 10 includes a plurality of unit cells 20 electrically connected in series. In this embodiment, six 3 V single cells are connected in series to construct an assembled battery 10 having a total voltage of 18 V. Specifically, each unit cell 20 is arranged by being inverted one by one so that the positive electrode side terminals 50 and the negative electrode side terminals 52 provided at both ends in the longitudinal direction are alternately arranged. One positive electrode side terminal 50 and the other negative electrode side terminal 52 are electrically connected between the cells 20 to be connected via a conductive connector 54 (for example, a bus bar). By connecting the adjacent unit cells 20 in series in this way, the assembled battery 10 having a desired total voltage (here, 18V) is constructed. In this embodiment, the negative electrode 52 of the unit cell 20 disposed at the left end (upstream side of the current flow path) is grounded to be a reference point (0 V), and each unit disposed at the right side (downstream side of the current flow path). It is constructed so that voltages of 3V, 6V, 9V, 12V, 15V, and 18V are sequentially applied through the battery 20.

  The container 40 constituting each unit cell 20 is a metal container. In this container 40, an electrode body to be described later is accommodated together with the electrolytic solution. The shape of the container 40 may be any shape that can accommodate the electrode body, and in this embodiment, an aluminum cylindrical container having good thermal conductivity is used. In this embodiment, the unit cell container 40 is connected to the positive electrode side terminal 50 and is electrically connected to the positive electrode of the electrode body via the positive electrode side terminal 50. Thereby, the cell container 40 constitutes a positive electrode terminal together with the positive electrode side terminal 50. Note that an insulating resin (gasket) (not shown) is interposed between the unit cell container 40 and the negative electrode side terminal 52, thereby ensuring the insulation between them.

  The metal wire 60 is wired across the plurality of single cells 20. In this embodiment, the metal wire 60 is made of a linear metal material (steel in this embodiment), and is wired along the arrangement direction (left-right direction) of the individual cells 20. Further, the metal wire 60 is attached to each of the unit cell containers 40. In the illustrated example, the metal wires 60 are arranged in the order of connection to each of the unit cell containers 40 (in order of series connection. In this example, the unit line 20 is arranged on the right side (downstream side) from the unit cell 20 arranged on the left end (upstream side). Are attached sequentially in the order of single cells). Note that the wiring of the metal wires 60 (the order of attachment to each battery) does not have to be the same as the series order of the batteries, and it is only necessary to clearly grasp the order of attachment. In this embodiment, the metal wire 60 is meandered in an S-shape and wound around each unit cell container 40 by approximately 1/2 turn. In addition, the wiring work of the metal wire 60 becomes easy by wiring the metal wire 60 according to the connection order of each unit cell.

Further, an insulating member 70 is interposed between the metal wire 60 and each of the unit cell containers 40. The insulating member 70 is made of an insulating material that melts by heat (solid becomes liquid) or contracts. In this embodiment, a thermoplastic resin having a softening point of 120 ° C. or lower (particularly preferably 100 ° C. or lower) (for example, Ethylene vinyl acetate copolymer or hydrocarbon resin).
Examples of other suitable thermoplastic resins include cellulose acetate, polyethylene, polypropylene, ABS, polycarbonate, polyacetal, unsaturated polyester resin, and polysulfone resin.

  The insulating member 70 only needs to be arranged so as to isolate and insulate between the metal wire 60 and the unit cell container 40. In this embodiment, the insulating member 70 is a covering member that covers the unit cell container 40. FIG. 2 shows the positional relationship between the unit cell container 40 covered with the insulating member 70 and the metal wire 60. As shown in FIG. 2, the metal wire 60 and each unit cell container 40 are isolated and insulated by an insulating member 70 that covers the unit cell container 40.

  Further, the insulating member 70 is configured to be melted by the heat generation (for example, a temperature rise exceeding 120 ° C.) when a thermal abnormality occurs in the single cell (for example, the single cell generates heat). The metal wire 60 and the abnormal battery cell container 40 are in contact with each other as the insulating member 70 is melted. For example, FIG. 3 shows an example in which the unit cell 20 arranged in the center generates heat, and a part (the lower side in the drawing) of the insulating member 70 covering the unit cell 20 is melted. In this example, as the insulating member 70 melts, a part (lower side in the figure) of the unit cell container 40 is exposed to the outside, and the unit cell container 40 and the metal wire 60 are in surface contact at the exposed part. (See symbol "90").

  By such contact (contact with the heated unit cell container), the metal wire 60 is electrically connected to the generated unit cell container 40, and the potential of the metal line 60 changes. In this example, since the metal wire 60 is in contact with the unit cell container 40 that functions as a positive electrode terminal, the potential increases from “0”. At this time, since the voltage accumulated in each unit cell 20 arranged on the upstream side (left side in the figure) of the generated unit cell is applied to the metal wire 60, the amount of change in the potential is generated by heat generation. The order of connection of the unit cells 20 differs.

  Furthermore, as shown in FIG. 1, the metal wire 60 is electrically connected to the control device 30. The control device 30 monitors a thermal abnormality (for example, heat generation due to malfunction due to the presence of a defective single cell or a failure of the charging device) of each unit cell 20 constituting the assembled battery 10, and sets the unit when an abnormal temperature rise occurs. Controls to shut off battery input / output. Specifically, the control device 30 is configured to measure a voltage applied to the metal wire 60 by the contact and detect a unit cell in which a thermal abnormality has occurred based on a measured value of the voltage. In addition, the control device 30 is configured to perform control to stop energization of the assembled battery when detecting the abnormal battery.

  In this embodiment, the control device 10 includes a measurement unit 32, a detection unit 34, and a stop unit 36. The measurement unit 32 performs control to measure a change in the potential of the metal wire 60 (that is, a voltage applied to the metal wire 60). The detection unit 34 performs control for detecting the unit cell in which the thermal abnormality has occurred based on the measured value of the voltage measured by the measurement unit 32. And the stop part 36 performs control which stops electricity supply of the assembled battery 10, when the detection part 32 detects a cell abnormal in heat. The control device 30 includes a calculation unit (for example, a CPU) (not shown) and a storage unit (for example, a flash memory) (not shown). And the measurement part 32, the detection part 34, and the stop part 36 perform each control mentioned above according to the program stored in the memory | storage part, respectively.

  Next, an operation (particularly, control by the control device 30) of the assembled battery control system 100 when a thermal abnormality occurs will be described.

  When a thermal abnormality (for example, overheating of the unit cell) occurs in any of the unit cells 20, the insulating member 70 that covers the generated unit cell container 40 is melted by heat (for example, a temperature rise exceeding 120 ° C.), and the melting is performed. Accordingly, the unit cell container 40 and the metal wire 60 that have generated heat come into contact with each other. Such a contact changes the potential of the metal wire 60.

  First, the measurement unit 32 of the control device 30 receives a change in the potential of the metal line 60 (in this case, an increase from “0”) and measures the change amount of the potential (that is, the voltage applied to the metal line 60). To do. As the measuring means, various known voltage measuring means can be preferably used.

  Next, the detection unit 34 of the control device 10 determines the measurement result of the voltage measured by the measurement unit 32 and various data (for example, the voltage per unit cell or the assembled battery 10 stored in advance in the storage unit). The unit cell 20 that generates heat is identified from the assembled battery 10 based on the arrangement data of the individual unit cells 20 to be configured). Specifically, the detection unit 32 divides the measured voltage value by the voltage per unit cell (measured voltage value / voltage per unit cell), and what number unit cell generates heat from the calculation result. To identify. In this embodiment, as shown in FIG. 1, an assembled battery is constructed by connecting six 3V single cells in series. Therefore, when the voltage measurement result is 12V, for example, the detection unit 34 is 4 from the left end. The unit cell 20 connected to the second is identified as a unit cell that has generated heat.

  Thereafter, the stop unit 36 of the control device 10 receives the detection of the unit cell 20 that has generated heat by the detection unit 34 and stops energization (for example, charging / discharging) of the assembled battery 10. Stopping energization may be performed by interrupting the input / output of the assembled battery 10 or may be performed by providing a separate current interrupt mechanism (for example, a current interrupt circuit) and operating the current interrupt mechanism.

  According to the assembled battery control system 100 having such a configuration, a simple configuration in which the metal wire 60 is wired across the unit cells 20 connected in series (for example, in the order of the series connection over the unit cells 20 connected in series). With the configuration in which the metal wire 60 is wired, the unit cell 20 in which a thermal abnormality such as overheating has occurred can be accurately identified. Therefore, it is not necessary to install an independent sensor (for example, a temperature sensor) in each unit cell 20, and the assembled battery control system 100 can be simplified. As a result, the cost of the assembled battery 10 itself for constructing the assembled battery control system 100 can be reduced.

  In addition, when the unit cell generates heat, energization (for example, charging / discharging) of the assembled battery 10 is stopped accordingly, so that the battery pack having excellent safety can quickly stop charging / discharging control of the assembled battery when the battery is abnormal. Can be provided.

  Note that the calculation process by the detection unit 34 may be executed while appropriately correcting in consideration of a change in discharge characteristics (for example, a decrease in voltage) of the unit cell due to aging. Alternatively, the storage unit stores the predicted values of the accumulated voltage corresponding to the order of connection of each unit cell as several sequences (3 V (first), 6 V (second), 9 V (third), etc.) in advance. And may be specified as a unit cell that generates heat by comparing the predicted value and the measured value.

  Moreover, the control apparatus 30 can memorize | store the position of the unit cell which generate | occur | produced in this way in the memory | storage part. The storage unit may be other than the storage unit that stores the control program described above, and may be any computer-readable recording medium (for example, an optical recording medium, a magnetic recording medium, a magneto-optical recording medium, a flash memory, or the like). According to such a configuration, when collecting and repairing an assembled battery in which an abnormality has occurred, an operator can easily grasp the unit cell that has generated heat by reading the position information stored in the storage unit (recording medium). And repair work can be performed efficiently.

  Alternatively, the control device 30 can cause the display unit to display the position of the generated unit cell thus identified. The display unit is, for example, an image display display installed outside the assembled battery control system. According to such a configuration, the operator can visually confirm (grasp) the position of the unit cell that has generated heat instantaneously. In addition, since the assembled battery 10 and the control device 30 are configured as separate bodies, when an abnormality occurs in the assembled battery, it is only necessary to remove the metal wire and replace the assembled battery in which the abnormality has occurred.

  The insulating member 70 may be configured to cover the entire unit cell container as in this embodiment, or may be configured to selectively cover a part of the unit cell container. . In addition, by covering the entire single cell container, the insulating member 70 can be used as an exterior material for preventing electric shock in a normal state. The thickness of the insulating member 70 may be a thickness that can reliably contact the metal wire 60 and the cell container 40 when the insulating member 70 is melted.

  The material of the insulating member 70 may be an insulating material that melts by heat, and is more preferably a thermoplastic resin having a softening point of 120 ° C. or lower (particularly 100 ° C. or lower). By using such a resin material that softens (and eventually becomes solubilized) at a low temperature, contact between the unit cell container and the metal wire during abnormal overheating can be performed quickly and reliably. In this embodiment, the abnormal temperature of the unit cell is set to 80 ° C. to 120 ° C., and an ethylene vinyl acetate copolymer and various hydrocarbon resins having a softening point (melting point) in such a temperature range are preferably used. In addition, the material of the insulating member 70 can be appropriately changed according to the use conditions of the assembled battery (for example, the abnormal temperature of the unit cell to be detected).

  The insulating member 70 is not limited to a material that melts by heat, but may be made of a material that contracts by heat. In this case, when the insulating member 70 is thermally contracted by heat, a part of the unit cell container 40 covered with the insulating member 70 is exposed, and the part of the exposed unit cell container 40 and the metal wire 60 are exposed. Can be contacted.

  It is preferable that the metal wire 60 is attached to a location where abnormal heat generated in the unit cell is easily sensed. For example, the metal wire 60 can be suitably attached near the center of the unit cell container in the longitudinal direction. Furthermore, it is preferable that the metal wire 60 is attached in a state in which it is urged in a direction in contact with the unit cell container 40. As shown in FIG. 1, such an urging force can be easily obtained by applying the appropriate tension to the metal wire 60 over the outer surface of the unit cell container 40 (stretching it in a stretched state with a pin). it can.

  According to the said structure, by energizing the metal wire 60 in the direction which contacts the cell container 40, the metal wire 60 and the cell battery container 40 can be contacted quickly and reliably at the time of a thermal abnormality. Further, the metal wire 60 can be brought into close contact with the unit cell container 40 by applying an appropriate tension, and the metal wire 60 can be firmly fixed to the unit cell container 40. Therefore, a fixing member for fixing the metal wire is not necessary.

  The metal wire 60 may have a thickness (diameter when the cross-sectional shape is circular) that is not easily cut by a tension or a voltage load at the time of installation. Further, the cross-sectional shape of the metal wire is not limited to a circle, but may be another shape (for example, a rectangle).

  The metal wire material is preferably a metal material having good conductivity and suitable elasticity. For example, a steel wire (for example, a piano wire) can be suitably used. By utilizing the elasticity of the steel, it can be put on the outer surface of the unit cell container 40 while maintaining an appropriate tension, and the adhesion between the metal wire 60 and the unit cell container 40 is improved.

  In this embodiment, although the case where the unit cell container 40 was a positive electrode terminal was shown, not only this but the unit cell container 40 may be a negative electrode terminal. Alternatively, even when the unit cell container is not an electrode terminal, the unit cell container and the electrolytic solution accommodated in the container are in direct contact (for example, the inner wall of the container and the electrolytic solution are not in contact with each other through an insulating film). The potential of the metal wire in contact with the container changes. Therefore, it is possible to detect the unit cell that has generated heat through the metal wire.

  Next, Modification Example 1 and Modification Example 2 of the assembled battery control system according to the present embodiment will be described with reference to FIGS. 4 and 5.

  The assembled battery control system 200 of Modification 1 shown in FIG. 4 differs from the assembled battery control system 100 according to the present embodiment in that the insulating member 70 covers a part of the unit cell container 40. That is, in the battery pack control system 200, the outer surface of the entire cell container is covered with a material 72 (for example, polypropylene, polyethylene, other polyolefin resin, etc.) that is difficult to melt to prevent electric shock, and a part thereof is cut away. A part of the cell container 40 is exposed. A metal wire 60 is wired to the exposed portion 44 via an insulating member 70.

  5 is different from the assembled battery control system 100 according to the present embodiment in that the metal wire 60 is covered with the insulating member 70. Even when the metal wire 60 covered with the insulating member 70 is used, as long as the metal wire 60 and the unit cell container 40 come into contact with each other when the metal wire 60 is melted at the time of abnormal heat, the assembled battery control system 100 according to this embodiment is almost the same. The same action / effect can be obtained. In addition, since the metal wire 60 is not exposed to the outside, there is an advantage that the metal wire can be protected. As a modification of this example, the surface of the unit cell container 40 in addition to the metal wire 60 may be covered with an insulating member 70 made of the same material (for example, a hydrocarbon resin having a softening point at 100 ° C. or lower).

  Note that the assembled battery control system according to the present invention can be suitably employed particularly in the high-output assembled battery control system 400 including the assembled battery 10 in which a large number of single cells are connected in series. That is, as shown in FIG. 6, even in the assembled battery control system 400 including 50 or more unit cells 20, it is possible to detect a thermal abnormality of the entire assembled battery 10 by simply wiring one metal wire 60. The assembled battery control system 400 can be greatly simplified as compared with the case where independent sensors (for example, 50 or more temperature sensors) are installed in each unit cell 20. In addition, since the unit cell in which the thermal abnormality has occurred can be specifically identified, it is not necessary to analyze more than 50 unit cells in detail.

  Hereinafter, the configuration and materials of the unit cell 20 according to the present embodiment will be described in detail. The configuration of the unit cell 20 may be the same as that of a unit cell constituting a typical assembled battery, and a nickel-metal hydride battery, an electric double layer capacitor, and the like can be cited as a battery configuration suitable for the implementation of the present invention. A battery configuration particularly suitable for the implementation of the present invention is a lithium ion secondary battery. Since a lithium ion secondary battery is a battery that can achieve high output at high energy density, a high-performance power source, particularly a vehicle-mounted power source, can be constructed.

  Further, as described above, the unit cell 20 includes an electrode body including a positive electrode and a negative electrode, and a unit cell container 40 that accommodates the electrode body and the electrolyte. The structure of the electrode body accommodated in the container 40 will be described.

  The electrode body according to the present embodiment has a sheet-like positive electrode (hereinafter referred to as “positive electrode sheet”) and a sheet-like negative electrode (hereinafter referred to as “negative electrode sheet”) in total, like the electrode body of a normal lithium ion battery. It is a wound electrode body that is laminated together with a sheet-like separator (hereinafter referred to as “separator sheet”) and is wound while the positive electrode sheet and the negative electrode sheet are slightly shifted.

  As a result of the winding electrode body being wound while being slightly shifted as described above in the transverse direction with respect to the winding direction, each of the ends of the positive electrode sheet and the negative electrode sheet has a wound core portion (that is, the positive electrode of the positive electrode sheet). The active material layer forming portion, the negative electrode active material layer forming portion of the negative electrode sheet, and the separator sheet are closely wound around). A positive electrode current collector plate is attached to the protruding portion of the positive electrode side (that is, a portion where the positive electrode active material layer is not formed), and is electrically connected to the positive electrode side terminal 50 and the cell container 40. Note that the negative electrode side protruding portion (that is, the portion where the negative electrode active material layer is not formed) is electrically connected to the negative electrode side terminal 52 through the negative electrode side current collector plate.

In addition, the material and member itself which comprise this winding electrode body may be the same as that of the electrode body of the conventional lithium ion battery, and there is no restriction | limiting in particular. For example, the positive electrode sheet can be formed by applying a positive electrode active material layer for a lithium ion battery on a long positive electrode current collector. For the positive electrode current collector, an aluminum foil (this embodiment) or other metal foil suitable for the positive electrode is preferably used. As the positive electrode active material, one or more of materials conventionally used in lithium ion batteries can be used without any particular limitation. Preferable examples include LiMn ₂ O ₄ , LiCoO ₂ , LiNiO _{2 and the} like.

  On the other hand, the negative electrode sheet can be formed by applying a negative electrode active material layer for a lithium ion battery on a long negative electrode current collector. For the negative electrode current collector, a copper foil (this embodiment) or other metal foil suitable for the negative electrode is preferably used. As the negative electrode active material, one or more of materials conventionally used in lithium ion batteries can be used without any particular limitation. Preferable examples include carbon-based materials such as graphite carbon and amorphous carbon, lithium-containing transition metal oxides and transition metal nitrides.

  Moreover, what was comprised with porous polyolefin resin as a suitable separator sheet used between positive and negative electrode sheets is mentioned. When a solid electrolyte or a gel electrolyte is used as the electrolyte, there may be a case where a separator is unnecessary (that is, in this case, the electrolyte itself can function as a separator).

Examples of the electrolyte accommodated together with the wound electrode body in the container 40 include lithium salts such as LiPF ₆ . An appropriate amount (for example, concentration 1M) of lithium salt such as LiPF ₆ is dissolved in a nonaqueous electrolytic solution such as a mixed solvent of diethyl carbonate and ethylene carbonate (for example, a mass ratio of 1: 1) and used as an electrolytic solution. it can.

    The unit cell 20 of the present embodiment is constructed by housing the wound electrode body in the container 40 together with the electrolytic solution and sealing it with a gasket. Then, the unit cells 20 are arranged in a predetermined direction, and the unit cells 20 are connected in series to construct the assembled battery 10. Thereafter, the assembled battery control system 100 is constructed by attaching the metal wire 60 so as to extend over the outer surface of each unit cell container constituting the assembled battery 10 and connecting the metal wire 60 to a predetermined portion of the control device 30. The

  The assembled battery control system of the present invention is particularly suitable for controlling an assembled battery as a power source for a motor (electric motor) mounted on a vehicle such as an automobile. Therefore, as shown in FIG. 7, a vehicle 1 (typically an electric motor such as an automobile, particularly a hybrid automobile, an electric automobile, or a fuel cell automobile) provided with the assembled battery control system 100 having the configuration described above according to the present invention. A vehicle equipped with a vehicle.

  As mentioned above, although this invention was demonstrated by suitable embodiment, such description is not a limitation matter and of course various modifications are possible.

1 is an external perspective view schematically showing a configuration of an assembled battery control system 100. FIG. It is a figure which shows the positional relationship of the metal wire 60, the cell battery container 40, and the insulating member 70. It is a cross-sectional schematic diagram which shows the positional relationship of the metal wire 60, the single battery container 40, and the fuse | melted insulating member 70. FIG. It is an external appearance perspective view which shows typically the structure of the assembled battery control system 200 which concerns on the modification 1. It is an external appearance perspective view which shows typically the structure of the assembled battery control system 300 which concerns on the modification 2. 1 is an external perspective view schematically showing a configuration of an assembled battery control system 400. FIG. 1 is a side view schematically showing a vehicle 1 (automobile) provided with an assembled battery control system 100. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 10 assembled battery 20 single cell 30 control apparatus 32 calculating part 34 memory | storage part 40 single cell container 44 exposed part 50 of a container positive electrode side terminal 52 negative electrode side terminal 54 conductive connector 60 metal wire 70 insulating members 100, 200, 300 400 battery pack control system

Claims (13)

An assembled battery control system comprising an assembled battery in which a plurality of single cells including a metal container are connected in series, and a control device electrically connected to the assembled battery,
Wired across each of the unit cells connected in series, a metal wire attached to each of the unit cell container,
An insulating member interposed between each of the unit cell containers and the metal wire, and insulating the unit cell container and the metal wire;
The metal wire is electrically connected to the control device;
Here, when a thermal abnormality occurs in any of the unit cells, the metal wire and the unit cell container with the thermal abnormality come into contact with the insulation member being melted or contracted by the heat. ,
The assembled battery control system, wherein the control device is configured to measure a voltage applied to the metal wire by the contact and detect a unit cell in which the thermal abnormality has occurred based on a measured value of the voltage.   The assembled battery control system according to claim 1, wherein the metal wire is attached to each of the unit cell containers in an order in which the unit cells are connected in series.   3. The assembled battery control system according to claim 1, wherein the control device is configured to perform control to stop energization of the assembled battery when detecting the unit battery having the thermal abnormality. 4.   The assembled battery control system according to any one of claims 1 to 3, wherein the insulating member is made of a thermoplastic resin having a softening point of 120 ° C or lower and covers the unit cell container.   The assembled battery control system according to claim 1, wherein the insulating member is made of a thermoplastic resin having a softening point of 120 ° C. or less and covers the metal wire.   The assembled battery control system according to any one of claims 1 to 5, wherein the metal wire is attached in a state of being urged in a direction in contact with the unit cell container.   The assembled battery control system according to any one of claims 1 to 6, wherein the metal wire is attached so as to run over an outer surface of the unit cell container.   The assembled battery control system according to any one of claims 1 to 7, wherein the control device includes a storage unit that stores position information of a unit cell that is abnormal in heat. An assembled battery for constructing the assembled battery control system according to claim 1,
The assembled battery is configured by connecting a plurality of single cells including a metal container in series,
Wired across each of the unit cells connected in series, a metal wire attached to each of the unit cell container,
An insulating member interposed between each of the unit cell containers and the metal wire, and insulating the unit cell container and the metal wire;
Here, when a thermal abnormality occurs in any of the unit cells, the metal wire and the unit cell container with the thermal abnormality come into contact with melting or shrinking of the insulating member due to the heat. , Battery pack.   The assembled battery according to claim 9, wherein the insulating member is made of a thermoplastic resin having a softening point of 120 ° C. or less and covers the unit cell container.   The assembled battery according to claim 9 or 10, wherein the insulating member is made of a thermoplastic resin having a softening point of 120 ° C or lower and covers the metal wire.   The assembled battery according to any one of claims 9 to 11, wherein the metal wire is attached in a state of being biased in a direction in contact with the unit cell container.   A vehicle comprising the assembled battery control system according to any one of claims 1 to 8.

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