Storage battery module

A storage battery module 20 includes plural battery cells 320 in which a wound electrode group 322 having positive and negative electrodes, and positive and negative electrode collector plates 327a and 327b connected to the positive and negative electrodes are accommodated in a battery cell 321, and positive and negative external terminals 331 and 341 are provided to be exposed to outside of the battery case 321, a circuit board 350 including a temperature detecting wiring 302 of the battery cell 320 connected to the positive and negative external terminals 331 and 341, and a temperature sensor 381 for detecting a temperature of the battery cell 320 provided above the wiring 302.

TECHNICAL FIELD

The present invention relates to a storage battery module, and more in details, to a storage battery module having a temperature sensor of a battery cell.

BACKGROUND ART

A secondary battery cell, such as a lithium ion secondary battery cell, a nickel hydrogen secondary battery cell, a nickel-cadmium secondary battery cell and the like, has been spreading rapidly in recent years as a power source of a hybrid vehicle or an electric vehicle.

A secondary battery cell which is used as a power source for an automobile is made to be a storage battery module in which ordinarily, plural pieces of secondary battery cells are connected in series by a bus bar.

In a secondary battery cell, deterioration in a performance with regard to service life such as a reduction in capacity is liable to be brought about under a high temperature environment. Conversely, a reduction in an output of a battery is liable to be brought about under a low temperature environment.

Consequently, a secondary battery cell needs to be controlled at a pertinent temperature. Although it is inherently preferable to detect an inner temperature of a secondary battery cell, ordinarily, a surface temperature of a battery case of a secondary battery cell is detected by a temperature sensor in view of technology and in view of cost.

As such a structure, there is known a structure in which a temperature sensor is fastened to a bus bar connecting positive external terminals and negative external terminals of contiguous secondary cells, and a pair of lead terminals of the temperature sensor is soldered to a circuit pattern that is provided at a circuit board as described in Patent Literature 1.

CITATION LIST

Patent Literature

Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2002-246074

SUMMARY OF INVENTION

Technical Problem

According to the invention described in Patent Literature 1, a member of attaching the temperature sensor and the circuit pattern to which the lead terminal of the temperature sensor is soldered are configured by different members. Ordinarily, the bus bars and the circuit board are not disposed on the same plane but are arranged with a stepped difference therebetween. Consequently, the lead terminal of the temperature sensor needs to be folded to bend, and therefore, there poses a problem that an assembling performance is poor, and time and labor are taken for storage and transportation in a subassembled state.

Solution to Problem

A storage battery module according to a first aspect of the present invention includes plural battery cells in which an electrode group including a positive electrode and a negative electrode, and a positive electrode collector plate and a negative electrode collector plate connected to the positive electrode and the negative electrode are accommodated in a battery case, and a positive external terminal and a negative external terminal connected to the positive electrode collector plate and the negative electrode collector plate are provided to be exposed to outside of the battery case, a circuit board connected to the positive external terminal or the negative external terminal of the battery cell, and including a wiring for temperature detection having a land, a temperature sensor that is thermally bonded to the land of the wiring and detects a temperature of the battery cell, and a voltage detecting wiring for detecting a voltage of the battery cell connected to the land.

The storage battery module according to a fourth aspect of the present invention can be made to further include a bus bar connecting the external terminals of inverse polarities of the battery cells contiguous to each other, in which the circuit board includes through holes for inserting the positive external terminal and the negative external terminal, and the land is provided at a surrounding of the through hole in the storage battery module described in the first aspect.

The storage battery module according to a fifth aspect of the present invention includes plural battery cells in which an electrode group having a positive electrode and a negative electrode, and a positive electrode collector plate and a negative electrode collector plate connected to the positive electrode and the negative electrode are accommodated in a battery case, and a positive external terminal and a negative external terminal connected to the positive electrode collector plate and the negative electrode collector plate are provided to be exposed to outside of the battery case, a circuit board connected to the positive external terminal or the negative external terminal of the battery cell, and including a wiring for temperature detection having a land, a temperature sensor that is thermally bonded to the land of the wiring and detects a temperature of the battery cell, and a bus bar that connects the external terminals of inverse polarities of the battery cells contiguous to each other, in which the circuit board includes a through hole for inserting a projected portion formed at the bus bar, and the land is provided at a surrounding of the through hole.

The storage battery module according to a sixth aspect of the present invention can be made to be a mode in which the bus bar includes welding areas welded to the positive pole external connection terminal and the negative external connection terminal, each of the welding areas includes plural welding portions, and the bus bar includes a slit provided between the welding portions in the storage battery module described in the fifth aspect.

The storage battery module according to a seventh aspect of the present invention can be made to be a mode in which the projected portion of the bus bar and the land are soldered in the storage battery module described in the fifth or sixth aspect.

It is preferable that in the storage battery module according to an eighth aspect of the present invention, the temperature sensor is arranged on the land via a thermally conductive resin therebetween, and the land is formed such that a width of a portion at which the temperature sensor is disposed is narrower than a width of a portion connected to the external terminal in the storage battery module described in any one of the first to sixth aspects.

It is preferable that in the storage battery module according to a ninth aspect of the present invention, the wiring and the temperature sensor are thermally bonded via the thermally conductive resin in the storage battery module described in any one of the first to eighth aspects.

It is preferable that in the storage battery module according to a tenth aspect of the present invention, a voltage detecting wiring for detecting a voltage of the battery cell is formed at the land in the storage battery module described in the fifth aspect.

Advantageous Effects of Invention

According to the storage battery module of the present invention, the temperature sensor is provided above the voltage detecting wiring of the circuit board, and therefore, an assembling performance is improved.

DESCRIPTION OF EMBODIMENTS

First Embodiment

An explanation will be given of an embodiment of a storage battery module according to the present invention in reference to the drawings as follows.

The storage battery module of the present invention is applicable as, for example, a storage battery device of a vehicle-mounted power source device of an electric vehicle, particularly, an electric automobile although not intended to limit thereto. The electric automobile includes a hybrid electric automobile including an engine which is an internal combustion engine and a motor as a drive source of a vehicle, a pure electric automobile which configures a motor as an only drive source of the vehicle and the like.

Hence, an explanation will be given of a drive system for a hybrid automobile to which the storage battery module according to the present invention is applied.

FIG. 1is a block circuit diagram of a hybrid automobile drive system having a storage battery module according to an embodiment of the present invention.

A hybrid automobile drive system shown inFIG. 1includes a storage battery module device21, a battery control device100monitoring the storage battery module device21, an inverter device220converting a direct current power from the storage battery module device21into three phase alternating current power, and a motor-generator7for driving a vehicle. The motor-generator7is driven by the three phase alternating current power from the inverter device220. The inverter device220and the battery control device100are connected by CAN communication, and the inverter device220functions as a host controller for the battery control device100. The inverter device220is operated based on instruction information from a control device10.

The inverter device220includes a power module226, MCU222for controlling the inverter device, and a driver circuit224for driving the power module226. The power module226converts the direct current power supplied from the storage battery module device21into the three phase alternating current power for driving the motor-generator7as a motor. A smoothing capacitor having a large capacity of about 700 μF through about 2000 μF is provided between heavy current lines HV+ and HV− which are connected to the power module226, although not illustrated. The smoothing capacitor is operated to reduce voltage noise applied to an integrated circuit provided at the battery control device100.

An electric charge of the smoothing capacitor is substantially zero in an operation start state of the inverter device220, and when a relay RL is closed, a large initial current flows to the smoothing capacitor. There is a concern of melting to destruct the relay RL owing to the large current. In order to solve such problem, in accordance with an instruction from the control device10, MCU222charges the smoothing capacitor by bringing a precharge relay RLp from an open state to a closed state when the motor-generator7is started to be driven, and then, starts supplying a power from the storage battery module device21to the inverter device220by bringing the relay RL from an open state to a closed state and. MCU222carries out the charging operation while restricting a maximum current via a resistor Rp when the smoothing capacitor is charged. The relay circuit is protected, and the maximum current flowing through the battery cell and the inverter device220can be reduced to a prescribed value or lower and high safety can be maintained by doing such an operation.

Incidentally, the inverter device220operates the motor-generator7as a generator at the time of the vehicle braking by controlling a phase of the alternating current power generated by the power module226relative to a rotor of the motor-generator. That is, the inverter device220charges the storage battery module device21by making a power generated by driving the generator recur to the storage battery module device21by carrying out a regenerative braking control. The inverter device220operates the motor-generator7as the generator in a case where a charged state of the storage battery module device21is lower than a standard state. The three phase alternating current power generated by the motor-generator7is converted into the direct current power by the power module226and is supplied to the storage module device21. As a result, the storage battery module device21is charged.

On the other hand, in a case of power running where the motor-generator7is operated as a motor, MCU222controls a switching operation of the power module226by controlling the driver circuit224to generate a rotating field in a leading direction relative to the rotation of the rotor of the motor-generator7in accordance with an instruction of the control device10. In this case, the direct current power is supplied from the storage battery module device21to the power module226. Also, MCU222controls the switching operation of the power module226by controlling the driver circuit224to generate a rotating field in a lagging direction relative to the rotation of the rotor of the motor-generator7in a case where the storage battery module device is charged by the regenerative braking control. In this case, power is supplied from the motor-generator7to the power module226, and the direct current power of the power module226is supplied to the storage battery module device21. As a result, the motor-generator7is operated as the generator.

The power module226of the inverter device220carries out a power conversion between the direct current power and the alternating current power by carrying out conducting and interrupting operation at high speed. At this occasion, a large current is interrupted at high speed, and therefore, a large voltage variation is generated according to an inductance of a direct current circuit. The smoothing capacitor having the large capacity described above is provided for restraining the voltage variation.

The storage battery module device21is configured by, for example, here, two of storage battery modules20A and20B which are connected in series with each other. The respective storage battery modules20A and20B include a plurality of cell groups connected in series, and each cell group includes a plurality of battery cells connected in series with each other. The storage battery module20A and the storage batter module20B are connected in series with each other via a service disconnect SD-SW for maintenance and check in which a switch and a fuse are connected in series. The series circuit of the electric circuits is interrupted by opening the service disconnect SD-SW, and a current does not flow even when a circuit connected to a vehicle is produced assumedly at one portion of either of the storage battery modules20A and20B. High safety can be maintained by such a configuration. Also, even when an operator touches an interval between HV+ and HV− in checking, the touching operation is safe since a high voltage is not applied to the human body.

There is provided a battery disconnect unit BDU including the relay RL, the resistor Rp, and the precharge relay RLp at the heavy current line HV+ between the storage battery module device21and the inverter device220. A series circuit of the resistor Rp and the precharge relay RLp is connected in parallel with the relay RL.

The battery control device100mainly measures voltages of respective battery cells, measures a total voltage, measures a current, and adjusts a temperature of the battery cell and capacities of the respective battery cells and so on. For that purpose, plural battery controlling IC's (integrated circuits) are provided as cell controllers. The plural battery cells provided in the respective storage battery modules20A and20B are classified into plural cell groups, and cell controller IC's controlling the battery cells included in the respective cell groups are individually provided for the respective cell groups.

A battery storage device11is configured by the battery control device100and the storage battery module device21.

The battery control device100and the storage battery module device21are connected by a wiring for detecting a voltage via a connector provided at a board of the battery control device100as described later. The wiring for detecting the voltage is used for detecting a voltage of each battery cell configuring the storage battery module, and is used for discharging (balancing) of each battery cell. According to the present invention, the wiring for detecting the voltage is used further for charging.

Cell controllers IC1through IC4for controlling respective cell groups respectively include communication systems602and 1 bit communication systems604. In the communication system602for reading cell voltage values and transmitting various kinds of commands, the communication system602carries out serial communication with a microcomputer30controlling the storage battery module device21by a daisy chain system via an insulating element (for example, photocoupler) PH. The 1 bit communication system604transmits an abnormality signal when cell overcharging is detected. In an example shown inFIG. 1, the communication system602is divided into a higher-level communication path corresponding to the cell controllers IC1and IC2of the storage battery module20A and a lower-level communication path corresponding to the cell controllers IC3and IC4of the storage battery module20B.

That is, the microcomputer30functions as a control device at a level higher than the cell controllers IC1through IC4.

Each cell controller IC performs an abnormality diagnosis, and transmits an abnormality signal from a transmitting terminal in a case where each cell controller IC per se is determined to be abnormal, or in a case where each cell controller IC receives an abnormality signal from a cell controller IC at a higher level by a receiving terminal. On the other hand, the abnormality signal to be transmitted from the transmission terminal vanishes in a case where the abnormality signal which has been received already at the receiving terminal vanishes, or the abnormality determination of each cell controller IC per se becomes a normality determination. The abnormality signal is a 1 bit signal according to the present embodiment.

Although the microcomputer30does not transmit an abnormality signal to the cell controller IC, the microcomputer30transmits a test signal which is a quasi-abnormality signal to the 1 bit communication system604in order to diagnose whether the 1 bit communication system604which is the transmission path of the abnormality signal is correctly operated. The cell controller IC1which receives the test signal transmits the abnormality signal to the communication system604, and the abnormality signal is received by the cell controller IC2. The abnormality signal is transmitted from the cell controller IC2to the cell controllers IC3and IC4in this order, and finally returned from the cell controller IC4to the microcomputer30. When the communication system604is normally operated, the quasi-abnormality signal transmitted from the microcomputer30is returned to the microcomputer30via the communication system604. The communication system604can be examined by transmitting and receiving the quasi-abnormality signal from and to the microcomputer30in this way, and reliability of the system is improved.

A current sensor Si constituted of a Hall element or the like is installed in the battery disconnect unit BDU, and an output of the current sensor Si is inputted to the microcomputer30.

Also, signals with regard to a total voltage of the storage battery module device21and temperatures of respective battery cells are inputted to the microcomputer30, and measured respectively by an AD converter (ADC) of the microcomputer30. Temperature sensors are provided at plural locations in the storage battery modules20A and20B.

Incidentally, the microcomputer30controls a number of revolutions of a cooling fan cooling the storage battery modules20A and20B, or controls a driver adjusting a supply amount of cooling water and a number of revolutions of a pump, although not illustrated, based on the inputted temperatures of respective battery cells, or the average temperatures of the storage battery modules20A and20B.

Cell voltages of 32 pieces of the battery cells need to be equalized in order to maximally utilizing a performance of the storage battery module device21. For example, a regenerative operation needs to be stopped at a time point at which the battery cell having the highest voltage reaches an upper limit voltage in the regenerative charge in a case where dispersion in the cell voltages is large. In this case, although the cell voltages of the other battery cells do not reach the upper limit, the regenerative operation is stopped and the energy is consumed for braking Respective IC's carry out a discharging operation for adjusting capacities of the battery cells by a command from the microcomputer30in order to prevent such a situation.

A resistor and a balancing switch are arranged to be connected in series with each other between a positive terminal and a negative terminal of each battery cell, although not illustrated. Hence, the balancing switch is made ON by transmitting a discharge instruction from the microcomputer30in order to discharge the battery cell. Thereby, a balancing current flows through a path from the positive terminal, the resistor, the balancing switch, the resistor, to the negative terminal of the battery cell.

The communication systems602and604are provided among IC1through IC4as described above. The communication command from the microcomputer30is inputted to the communication system602via the photocoupler PH, and received by the receiving terminal of IC1via the communication system602. A data or a command in accordance with the communication command is transmitted from the transmitting terminal of IC1. The communication command received by the receiving terminal of IC2is transmitted from the transmitting terminal. Reception and transmission are carried out successively in this way, and a transmission signal is transmitted from the transmitting terminal of IC4and received by the receiving terminal of the microcomputer30via the photocoupler PH. IC1through IC4carry out transmission of measured data of the cell voltage and the like to the microcomputer30, or the balancing operation in accordance with the received communication command. Respective IC1through IC4detect cell overcharge based on the measured cell voltage. The detection result (abnormality signal) is transmitted to the microcomputer30via the signal system604.

The storage battery module device21is connected to the battery control device100by a wiring301for detecting the voltage via a connector401as described above.

Signals with regard to the total voltage of the storage battery module device21and temperatures of the respective battery cells are inputted to the microcomputer30.

The storage battery module device21is connected to the current sensor Si, and the output of the current sensor Si is inputted to the microcomputer30.

When the motor-generator7is operated as a generator, a power generated by the motor-generator7charges the respective battery cells of the storage battery module device21by the regenerative control. In a case where the battery cell in the storage battery module device21is overcharged, the battery cell is discharged via the balancing switch (not illustrated).

The storage battery module device21is configured by connecting the two storage battery modules20A and20B by the service disconnect SD-SW.

The respective battery cells of the respective storage battery modules20A and20B are connected to the wirings301for detecting the respective voltages formed at circuit boards350as illustrated inFIG. 1by a two-dotted chain line. The circuit board350is provided with the connector401, and the wirings301for detecting the respective voltages are connected to the battery control device100via the connector401.

An explanation will be given of structures of the storage battery modules20A and20B as follows. However, the storage battery modules20A and20B basically have the same function and the same structure. Therefore, an explanation will be given of a storage battery module20as a representative.

FIG. 2is a perspective view of an outlook of the storage battery module according to the embodiment of the present invention, andFIG. 3is a total side view viewing the storage battery module illustrated inFIG. 2from a side face thereof.

The storage battery module20includes 8 pieces of battery cells320. Each battery cell320is, for example, a prismatic lithium ion secondary cell, and has a flat rectangular parallelepiped shape as a whole. The battery cell320includes a battery case321, and a positive external terminal331and a negative external terminal341which are projected to outside of the battery case321.

The battery cells320are aligned with wide width faces thereof are brought into close contact with each other by directing the positive external terminals331and the negative external terminals341inversely alternately, in other words, in a state where the external terminals having inverse polarities are made to be opposed to each other.

The contiguous positive and negative external terminals331and341are connected by a bus bar361. In this case, the positive external terminal331and the negative external terminal341of one piece of the battery cell320are respectively connected to the negative external terminal341and the positive external terminal331of the different battery cells320, and all of 8 pieces of the battery cells are connected in series with each other. The negative external terminal341of the first battery cell320and the positive external terminal331of the final battery cell320connected in series with each other are not connected by the bus bar361, but directly connected to the voltage detecting wirings301as described later.

The circuit board350is arranged on the bus bar361. An upper face of the circuit board350is formed with the plural voltage detecting wirings301, and the temperature detecting wirings302and provided with the connector401connected with the wirings301and302.

The voltage detecting wirings301are connected to an operational amplifier via a multiplexer although not illustrated. The voltages of the respective battery cells320are detected by the operational amplifier by successively switching connections with the battery cells320by a multiplexer. The detected voltages of the respective battery cells320are converted into digital values at an A/D converter circuit and stored in a memory unit of the microcomputer30.

The positive external terminal331and the negative external terminal341connected by the single bus bar361are at the same potential. Hence, the voltage detecting wiring301is provided in correspondence with the respective external terminals connected by the bus bar361. The present embodiment exemplifies a case where the wirings301for detecting the voltages are formed in correspondence with the respective negative external terminals341.

The circuit board350is formed with lands351in correspondence with the respective negative external terminals341. The negative external terminal341and the positive external terminal331are members in a bolt-like shape formed with screwed portions at outer peripheries thereof, and respectively fixed to the circuit board350by nuts359.

The circuit board350is formed with the land351in correspondence with the negative external terminal341, and the negative external terminal341is thermally and electrically connected to the land351via the nut359by fastening the nut359.

Lands352having a shape different from that of the land351are formed in correspondence with the negative external terminal341of the battery cell320arranged substantially at a center portion of the storage battery module20and the positive external terminal331of the battery cell320disposed at a final position of the alignment of the storage battery module20.

The land352includes a projected portion353extended to a center side of the circuit board350. A temperature sensor (temperature detector)381is mounted above the projected portion353of the land352by riding over the projected portion353. The voltage detecting wiring301is connected to the projected portion353of the land352. The temperature detecting wirings302are connected to a pair of connection terminals of the temperature sensor381. Other end sides of the temperature detecting wirings302are connected to the connector401.

FIG. 4is an enlarged sectional view cut along a line IV-IV of the storage battery module20illustrated inFIG. 2.

The battery cell320includes the battery case321in a prismatic flat shape. The battery case321is configured by a battery can321ahaving an opening at an upper portion thereof, and a lid321bbonded to the battery can321aby laser welding or the like to close the opening portion of the battery can321a. The lid321bis formed by, for example, aluminum.

The lid321bis formed with a through hole for inserting an electrode connection plate323which is connected to the positive external terminal331or the negative external terminal341. The through hole is fitted with an insulating member325having an opening portion at a center portion thereof, and the electrode connection plate323is fitted to the through hole of the insulating member325.

A wound electrode group322is accommodated at inside of the battery case321. The wound electrode group322is formed by winding a positive pole electrode and a negative pole electrode, with a separator interposed therebetween, into a flat shape, although not illustrated.

In a case of a lithium ion secondary cell, the positive pole electrode is coated with positive electrode active-material-mix layers on both faces of a positive pole metal foil configured by, for example, an aluminum foil or the like. The positive electrode active-material-mix layer is coated such that an untreated portion of the positive electrode active-material-mix layer where the positive pole metal foil is exposed is formed at one side edge of the positive pole metal foil.

The negative electrode is coated with negative electrode active-material-mix layers on both faces of a negative pole metal foil configured by a copper foil or the like. The negative electrode active-material-mix layer is coated such that an untreated portion of the negative electrode active-material-mix layer where the negative metal foil is exposed is formed at other side edge of the negative electrode pole metal foil which is a side edge opposed to the side edge of the positive pole metal foil where the untreated portion of the positive electrode active-material-mix layer is arranged.

The positive electrode active-material-mix is produced by adding 10 weight parts of scaly graphite as an electrically conductive material and 10 weight parts of PVDF as a binding agent to 100 weight parts of lithium manganese oxide (chemical formula LiMn2O4) as a positive electrode active material, adding NMP to the active material mix as a dispersion solvent, and kneading the active material mix. The positive electrode active-material-mix layer is coated on both faces of an aluminum foil having a thickness of 20 μm while leaving the untreated portion of the positive electrode active-material-mix. Thereafter, the coated entity is dried, pressed, and cut to thereby provide the positive pole electrode having a coated portion of the positive electrode active material of a thickness of 90 μm which does not include the aluminum foil.

The negative electrode active-material-mix is produced by adding 10 weight parts of polyvinylidene fluoride (hereinafter, referred to as PVDF) as a binding agent to 100 weight parts of an amorphous carbon powder as a negative electrode active material, adding N-methylpyrrolidone (hereinafter, referred to as NMP) as the dispersion solvent to the active material mix, and kneading the active material mix. The negative electrode active-material-mix is coated on both faces of a copper foil having a thickness of 10 μm while leaving the untreated portion of the negative electrode active-material-mix. Thereafter, the active material mix is dried, pressed, and cut to thereby provide the negative pole electrode having the coated portion of the negative electrode active material of a thickness of 70 μm which does not include the copper foil.

A nonaqueous electrolyte is filled into the battery case321. As the nonaqueous electrolyte, there is used, for example, the nonaqueous electrolyte dissolving lithium phosphate hexafluoride into a mixture solution of ethylene carbonate (EC), dimethyl carbonate (DMC), and diethyl carbonate (DEC) having volume ratios of 1:1:1 to be 1 mol/L.

At the electrode connecting plate323on one side, a positive electrode collector plate327ais fixed to the lid321bby calking or the like. The positive electrode collector plate327ais formed by aluminum or the like.

At the electrode connection plate323on the other side, a negative electrode collector plate327bis fixed to the lid321bby calking or the like. The negative electrode collector plate327bis formed by copper or the like.

In the wound electrode group322, layers of the untreated portion of the positive electrode active-material-mix of the wound positive pole electrode are laminated on top of another on one edge side, and layers of the negative electrode active-material-mix untreated portion of the negative electrode active-material-mix are laminated on top of another on the other edge side opposed to the one edge side.

The positive electrode collector plate327aand the negative electrode collector plate327bhave a shape of being folded to bend from an attaching portion attached to the lid321bsubstantially in a vertical direction, inclined to a center portion side in a thickness direction of the battery cell320, and bent again at a center portion in the direction vertical to the attaching portion. At the center portion, the positive electrode collector plate327ais bonded to the untreated portion of the positive electrode active-material-mix, and the negative electrode collector plate327bis bonded to the untreated portion of the negative electrode active-material-mix by ultrasonic welding or the like.

The collector plates327aand327bas well as the electrode connection plates323of the positive and negative poles are insulated from the lid321bby the insulating members325.

The positive external terminal331or the negative external terminal341respectively formed with screwed portions on outer peripheries are connected onto the respective electrode connection plates323. The connection can be carried out by calking the positive external terminal331or the negative external terminal341and the respective electrode connection plates323directly or via electrically conductive connection plates (not illustrated).

The positive external terminal331and the negative external terminal341respectively include large diameter portions331aand341a.

The positive external terminal331and the negative external terminal341contiguous to each other are connected by the bus bar361. The bus bar361is formed with through holes for inserting the positive external terminal331and the negative external terminal341. The positive external terminal331and the negative external terminal341are inserted to the through holes, and the bus bar361is bonded to the large diameter portions331aand341aof the positive and the negative external terminals331and341by arc welding of TIG (Titan Inert Gas).

A voltage detecting circuit board330is mounted on the bus bar361.

FIG. 5is a plane view on an upper face side of the voltage detecting circuit board350, andFIG. 6is a plane view on an upper face side of the storage battery module20. In the following explanation,FIG. 4as well asFIG. 5andFIG. 6are referred.

The circuit board350is formed with the land351in correspondence with the negative external terminal341. The lands352are formed in correspondence with the negative external terminal341of the battery cell320arranged substantially at a center portion of the storage battery module20, and the positive external terminal331of the battery cell320disposed at the final location of the alignment of the storage battery module20. The circuit board350is formed with through holes355for inserting the positive external terminals331or the negative external terminals351.

The positive external terminals331and the negative external terminals341are projected to the upper side of the circuit board350by passing through the through holes355of the circuit board350. The circuit board350and the bus bars361are fastened by screwing the nuts359to the projected portions. Thereby, 8 pieces of the battery cells320and the circuit board350are integrated.

Under the state, a thermal and electrical connection is carried out by a path of the negative electrode active-material-mix untreated portion of the wound electrode group322, the negative electrode collector board327b, the electrode connection plate323, the negative external terminal341, the nut359, and the land351or352on the negative electrode side. A thermal and electrical connection is carried out at the land352formed in correspondence with the positive external terminal331of the battery cell320disposed at the final location of the alignment of the storage battery module20, by a path of the positive electrode active-material-mix untreated portion of the wound electrode group322, the positive electrode collector plate327a, the electrode connection plate323, the positive external terminal331, the nut359, and the land352.

A projected portion353having a width narrower than that of a portion of fastening the nut359is formed at the land352provided at the circuit board350as illustrated inFIG. 5. Pads354are provided on both sides in a width direction of the projected portion353of the circuit board350. The temperature detecting wirings302formed at the circuit board350connect the respective pads354and the connector401. A thermally conductive member362configured by a putty or an adhering sheet having a high thermal conductivity is formed on the projected portion353of the land352. As the thermally conductive member362, for example, a silicone species resin or the like can be used.

A temperature sensor381is mounted on the thermally conductive member362. The temperature sensor381is of a chip type and is arranged with a pair of connection terminals381aand381bin a state of riding over the projected portion353of the land352in a width direction to respectively correspond to the pads354. The pair of connection terminals381aand381bis respectively soldered to the pads354by a soldering operation. The thermally conductive member operates to prevent a thermal conductivity from lowering by interposing air between the land352and the temperature sensor381.

FIG. 6illustrates a plane view from an upper face side of the storage battery module20formed in this way.

In the battery storage module20according to the present embodiment, the positive external terminal331and the negative external terminal341of the contiguous battery cells320are connected by the bus bar361. The respective negative external terminals341are connected to the voltage detecting wirings301via the lands351or352provided at the circuit board350. The negative external terminal341of the first battery cell320and the positive external terminal331of the last battery cell320in the alignment of the storage battery module20are directly connected to the voltage detecting wiring301provided at the circuit board250.

Consequently, dispersion in voltages among the battery cells320can be reduced by detecting the voltages of the respective battery cells, inputting signals concerning the voltages to the microcomputer30via the battery control device100, and controlling to charge and discharge the respective battery cells320.

In the storage battery module20according to the present embodiment, the temperature sensor381is mounted at the land352formed at the circuit board350. Temperatures of the respective battery cells320are transferred to the lands352via the negative external terminals341and the nuts359, and therefore, the temperatures of the respective battery cells320can be detected by the temperature sensors381. Signals concerning the temperatures detected by the temperature sensors381are inputted to the microcomputer30through the temperature detecting wirings302formed at the circuit board350via the battery control device100. The microcomputer30can control a number of revolutions of a cooling fan or a driver and a number of revolutions of a pump for adjusting an amount of supplying cooling water based on the inputted temperatures of the respective battery cells320or an average temperature of the storage battery module20, although not illustrated.

In the battery storage module20according to the present embodiment, the temperature sensor381is mounted at the land352formed at the circuit board350as described above. The land352and the temperature detecting wiring302are formed on the same circuit board350. Therefore, an assembling performance is excellent and productivity can be improved.

In the storage battery module20according to the present embodiment, the land352executes the voltage detecting and the temperature detecting functions. Therefore, a detection temperature is accurate and an area of the circuit board350can be reduced.

In the storage battery module20according to the present embodiment, the chip type temperature sensor381is mounted at the circuit board350. Therefore, a circuit board assembly can be reduced, storage and transportation are facilitated, and efficiency is also improved.

In the storage battery module20according to the present embodiment, the thermally conductive member382is interposed between the chip type temperature sensor381and the projected portion353of the land352. Therefore, the temperature of the battery cell320can accurately be detected by preventing air from being interposed between the land352and the temperature sensor381.

Second Embodiment

FIG. 7is a front view of a battery cell configuring a storage battery module according to Second Embodiment of the present invention, andFIG. 8is a total side view showing Second Embodiment of the storage battery module of the present invention.

According to Second Embodiment, there is configured a structure where a bus bar includes a bonding member bonding to a land of a circuit board.

An explanation will be given of the storage battery module according to Second Embodiment of the present invention in reference to the drawings as follows. The explanation will be given mainly of a configuration which differs from that of First Embodiment. The explanation will pertinently be omitted of a configuration the same as that of First Embodiment by attaching the same notation to the corresponding member.

Also the storage battery module500including8pieces of battery cells510is exemplified in Second Embodiment.

In the battery cell510, a positive external terminal520and a negative external terminal530which are formed by being projected from the lid321bof the battery case321while being insulated by the insulating member325are formed by a flat plate-like member which is not in a bolt-like shape.

A structure is configured such that the positive external terminal520and the negative external terminal530of one piece of the battery cell510are respectively connected to the negative external terminal530and the positive external terminal520of the different batter cells510by bus bars540similar to First Embodiment.

However, through hole formed at a circuit board550are not formed to respectively correspond to the negative external terminal530and the positive external terminal520, but a single through hole is formed for a pair of the positive and the negative external terminals520and530.

A projected portion542formed at the bus bar540is inserted to the through hole and is projected to an upper side of the circuit board550.

FIG. 9is a sectional view enlarging vicinities of the positive terminal and the negative terminal of a pair of the battery cells contiguous to each other, and is a sectional view cut along a line IX-IX of the storage battery module500illustrated inFIG. 13described later.

The positive external terminal520and the negative external terminal530respectively include lower portions fixing the positive electrode and the negative electrode collector plates327aand327band upper portions having flat outer faces.

A main body portion541of the bus bar540is welded to the respective upper portions of the positive external terminal520and the negative external terminal530. The bus bar540includes a projected portion542vertically erected from the main body portion541, and the projected portion542is soldered to a land552or551formed at a circuit board550. InFIG. 9, numeral591designates a solder layer.

FIG. 10is a perspective view of an outlook of the bus bar540.

The bus bar540has a shape in line symmetry with respect to a center in a longitudinal direction. The main body portion541of the bus bar540is formed with slits543extended in the longitudinal direction and opened to outside at an end portion thereof substantially at a center in a width direction of the main body portion541. Circular openings544are formed substantially at centers of the respective slits543. The projected portion542erected substantially vertically to the main body portion541is formed at one side edge of a center portion of the main body portion541.

The bus bar540can be formed by pressing a plate-like member. The projected portion542of the bus bar540is formed as an erected piece, and an upper face thereof has a slender rectangular shape.

FIG. 12is a plane view of a voltage detecting circuit board according to Second Embodiment, andFIG. 13is a plane view viewing the storage battery module500illustrated inFIG. 8from an upper side.

The circuit board550is formed with a through hole561having a slender rectangular shape in plane view at a position in correspondence with a boundary portion of the battery cells510contiguous to each other. The through holes561are formed also at positions of the negative external terminal530of the first battery cell510of an alignment of the storage battery module500and the positive external terminal520of the last battery cell510.

The projected portion542of the bus bar540is fitted to the through hole561of the circuit board550. The through hole561and the projected portion542of the bus bar540are formed in a rectangular shape prolonged in the longitudinal direction, and therefore, rattling in a state of the projected portion fitted to the through hole561can be reduced.

Bus bars540A having a shape different from that of the bus bar540are fitted to the through holes561formed at positions in correspondence with the negative external terminal530of the first battery cell510of the alignment of the storage battery module500and the positive external terminal520of the last battery cell510.

FIG. 11is a perspective view of an outlook of the bus bar540A.

The bus bar540A is bonded to only one of the positive and the negative external terminals520and530. Therefore, the bus bar540A has a shape of cutting off substantially a half in the longitudinal direction of the bus bar540. However, the projected portion542of the bus bar540has a shape and a dimension the same as those of the projected portion542of the bus bar540. Therefore, all of the through holes561formed at the circuit board550can be configured by the same shape and dimension and can be made to have a general purpose property.

The bus bars540or540A is bonded to the positive external terminal520or the negative external terminal530by arc welding of TIG welding or the like.

InFIG. 10andFIG. 11, welded portions “w” welded to the positive and the negative external terminals520and530are indicated by dotted lines. Each of the positive and negative external terminals520and530is welded at four locations. Welded portion “w” are disposed at positions in the width direction where the slit543is substantially centered and positions in the longitudinal direction where the circuit opening544is substantially centered.

A function of the slit543and the circular opening544resides in improving welding between the bus bar540or540A and the positive and the negative external terminals520and530. In welding of arc welding or the like, it is important that the thermal energy in welding does not disperse to surroundings of a welded portion of a welded body but is concentrated on the welded portion in order to improve welding.

The bus bar540and540A are formed with the slit543and the circular opening544among the respective welded portions “w”. The thermal energy for welding radiated to the bus bar540or540A is blocked by the slit543and the circular opening544from thermally conducted to surroundings.

Therefore, heat accumulated at the bus bar540or540A is conducted to the positive and the negative external terminals520and530arranged right therebelow. That is, the thermal energy is concentrated on the welded portion “w”, the welded portion “w” is melted at a temperature higher than those of surroundings, and excellent bonding is carried out.

A land551in a rectangular shape in plane view is formed at a surrounding of each through hole561of the circuit board550as illustrated inFIG. 12. Also, lands552having a shape different from that of the land551are formed at surroundings of the through holes561disposed at one side edge of a substantially center portion and a vicinity of one corner portion of the circuit board550illustrated inFIG. 12.

The land552includes a projected portion553extended to a center side of the circuit board550similar to the land352shown in First Embodiment. A thermally conductive member362is formed on the projected portion553.

Pads554are formed on both sides in a width direction of the projected portion553of the circuit board550.

The voltage detecting wiring301is connected to each land551. The voltage detecting wiring301is also connected to a front end portion of the projected portion553of the land352. The temperature detecting wiring302is connected to each pad554.

As illustrated inFIG. 13, the projected portion542of the bus bar540is fitted to the through hole561of the circuit board550, and the projected portion542is soldered to the land551or552.

In this case, the projected portions542of the bus bar540A are fitted to the through holes561formed in correspondence with the negative external terminal530of the first battery cell510of the alignment of the storage battery module500and the positive external terminal520of the last battery cell510. The projected portion542of the bus bar540A is also soldered to the land551or552.

The chip type temperature sensor381is mounted on the thermally conductive member362formed on the projected portion553of the land552, and the pair of connection terminals381aand381bof the temperature sensor381is soldered to the pads554.

In the storage battery module500according to Second Embodiment of the present invention, the positive external terminal520and the negative external terminal530of the battery cells510contiguous to each other are connected by the bus bar540. Each negative external terminal530is connected to the voltage detecting wiring301via the land551or552provided at the circuit board550. The negative external terminal530of the first battery cell510of the alignment of the storage battery module500and the positive external terminal520of the last battery cell510are directly connected to the voltage detecting wirings301provided at the circuit board550.

Therefore, the voltages of the respective battery cells are detected, signals with regard to the voltages are inputted to the microcomputer30via the battery control device100, charging and discharging of the respective battery cells510are controlled, and dispersion of voltages among the battery cells510can be reduced.

In the storage battery module500according to Second Embodiment of the present invention, the temperature sensor381is mounted to the land552formed at the circuit board550. Temperatures of the respective battery cells510are transferred from the positive and the negative external terminals520and530to the lands552via the bus bar540, and therefore, temperatures of a pair of the battery cells320can be detected by the temperature sensor381. Therefore, the inputted temperatures of the respective battery cells510or the storage battery module500can be controlled by the microcomputer30similar to the case of First Embodiment.

In the storage battery module500according to Second Embodiment of the present invention, the land552executes a voltage detecting function and a temperature detecting function. Therefore, a detected temperature is accurate and an area of the circuit board550can be reduced.

In the storage battery module500according to Second Embodiment of the present invention, the chip type temperature sensor381is mounted to the circuit board550. Therefore, a circuit board assembly can be reduced, storage and transportation are facilitated, and efficiency is also improved.

In the storage battery module500according to Second Embodiment of the present invention, the bus bar540bonding the positive external terminal520and the negative external terminal530of the battery cells510contiguous to each other is directly fixed to the land551or552of the circuit board550. Therefore, a number of parts can be reduced more than in the case of First Embodiment, and productivity can be improved.

Incidentally, in the respective embodiments described above, there is exemplified a case of detecting temperatures of the battery cells320and510of the storage battery modules20and500at portions of two locations. However, all of the lands formed at the circuit boards350and550may be configured by shapes having the projected portions353and553for mounting the temperature sensors381as in the lands352or552.

When the temperatures of the respective cells320and510are detected in this way, in the battery control device100, the temperatures can also be controlled respectively for the storage battery modules20and500by calculating average temperatures of the storage battery modules20and500other than monitoring and controlling the temperatures respectively for the pairs of battery cells320and510connected by the bus bars, and a control having a high reliability can be carried out.

In a case of a structure of detecting the all temperatures of pairs of battery cells320and510connected by the bus bars, the case is expensive as a whole. Therefore, the battery cells320and510at positions at which temperatures become the highest temperatures and the lowest temperatures may previously be confirmed by test or the like for respective storage battery modules, and the temperatures of the battery cells320and510at such positions may be detected.

In the respective embodiments described above, there is exemplified a case where the lands352and552for detecting temperatures are provided on upper face sides of the circuit boards350and550. However, there may be constructed a through hole structure in which the lands352and552are also provided at lower faces of the circuit boards350and550, and the upper and lower lands352and552are connected by the thermally conductive members. Thereby, thermal conductivities from the battery cells320and510to the lands can further be improved.

In the respective embodiments described above, there is exemplified a case where the lands352and552execute the voltage detecting function and the temperature detecting function. However, the temperature detecting land and the voltage detecting land may be formed separately from each other. As an example thereof, there is exemplified a case where the temperature detecting land and wirings are formed at one face of the circuit board, and the voltage detecting land and wirings are formed at the other face of the circuit board. In a case where temperatures of all of the battery cells320and510are made to be detected, a number of wirings is increased, the circuit board is large-sized, and therefore, the case can be dealt with by configuring the both face circuit board.

In the respective embodiments described above, there is exemplified a structure in which the lands352and552and the battery cells320and510are connected by fastening members or soldering. However, the present invention is not limited to the method but various methods are applicable to the present invention. For example, hook portions may be provided to the positive and the negative external terminals331and341in the case of First Embodiment and to the projected portion542of the bus bar540in the case of Second Embodiment, and the hook portions may be brought into contact with the lands352and552. In this case, the hook portions may be folded to bend to press to the lands352and552.

The storage battery modules20and500shown in the respective embodiments described above are applicable also to storage battery devices configuring power source devices other than that of an electric vehicle such as power source devices used in an interruption free power source device and a private power generation equipment which are used in a computer system, a server system and the like.

Otherwise, the storage battery module of the present invention can variously be modified to configure within the range of the gist of the present invention. In short, the storage battery module of the present invention may include plural battery cells in which an electrode group having positive pole and the negative pole electrodes, and positive electrode and negative electrode collector plates connected to the positive pole and the negative pole electrodes are accommodated in a battery cell, and the positive and the negative external terminals connected to the positive electrode and the negative electrode collector plates are provided to expose to an external portion of the battery cell, a circuit board having a wiring for detecting a temperature connected to the positive or the negative external terminal of the battery cell, and a temperature sensor thermally bonded to a wiring for detecting a temperature of the battery cell.