Battery system

A battery system comprises an assembled battery in which a plurality of battery cells are connected in series, a temperature sensor for detecting temperature of the battery cells of the assembled battery, and a voltage detecting line connected to a voltage detecting location of the battery cell. Further the battery system fixes the connecting terminal at the voltage detecting location. The connecting terminal fixes the temperature sensor in a thermally coupling state, and electrically connects the voltage detecting line.

This application is a U.S. national stage application of the PCT international application No. PCT/JP2014/000510

TECHNICAL FIELD

The present invention is related to a battery system having an assembled battery and a temperature sensor to detect temperature of the assembled battery.

BACKGROUND ART

A battery system having a high output voltage by connecting a plurality of battery cells in series is used for supplying power to electric equipment devices such as a motor or a starter of an electric vehicle, a car navigation, or an audio. In a state where the temperature or the voltage of the battery is out of the range of normal and safe usage, normal operation is not kept, and then there is a possibility that degradation of life, or the battery with smoking or burning might occur. Therefore, it is important for keeping a safety to monitor temperature or voltage of the battery. Additionally, in a safety monitoring of the battery system, when an abnormal state of the battery temperature is detected, it is necessary to immediately perform an operation such as turning off a relay connected to an output side. Therefore, it is also important to detect the abnormal state of the battery temperature. Thus, the battery is required to quickly detect the temperature or the voltage of the battery.

The battery system where the battery temperature is detected by the temperature sensor for detecting the temperature of the battery, has been developed. (refer to patent literature 1)

CITATION LIST

Patent Literature

SUMMARY OF THE INVENTION

In the battery system of patent literature 1, separators are disposed so as to sandwich the separators between prismatic shaped batteries, and a temperature sensor is coupled to the separator. In this battery system, it has a trouble to exactly dispose the temperature sensor at a most suitable specific location for detecting the temperature. Additionally, it is also difficult to dispose the temperature sensor at a fixed position without slippage of the temperature sensor in a long time.

The present disclosure is developed for the purpose of solving such drawbacks. One non-limiting and explanatory embodiment provides a battery system where the temperature sensor is simply and easily disposed also at a suitable location for detecting the battery temperature and further the temperature sensor is disposed at a fixed position without slippage of the temperature sensor in a long time.

A battery system of the present disclosure comprises an assembled battery in which a plurality of battery cells are connected in series, a voltage detecting line for detecting voltage of the battery cells constituting the assembled battery10, and a temperature sensor for detecting temperature of at least one of the battery cells constituting the assembled battery. The assembled battery has a voltage detecting location to which the voltage of the battery cells detected by the voltage detecting line is applied, and the voltage detecting location is thermally coupled to an electrode terminal of at least one of the battery cells. The voltage detecting line has a connecting terminal provided at a tip thereof, and the connecting terminal is fixed at the voltage detecting location. The temperature sensor is provided at the connecting terminal, and is fixed to the connecting terminal in a thermally coupling state.

The vicinity of the electrode terminal of the battery cell is a current path outputted from the battery cell, and as heat generation inside the battery cell is conducted, the vicinity of the electrode terminal is apt to becomes comparatively high temperature. In the battery system of the present disclosure, as the temperature sensor is fixed to the connecting terminal of the voltage detecting line provided in the vicinity of the electrode terminal of the battery cell, the temperature sensor can be simply and easily disposed surely at a suitable location for detecting the temperature of the battery cell.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the embodiment of the present invention will be described referring to drawings. However, the following embodiments illustrate a battery system, an electric vehicle or a power storage device having this battery system which is aimed at embodying the technological concept of the present invention, and the present invention is not limited to the battery system, the electric vehicle or the power storage device having this battery system described below. However, the members illustrated in Claims are not limited to the members in the embodiments.

A battery system of the present disclosure comprises an assembled battery in which a plurality of battery cells are connected in series, a temperature sensor for detecting temperature at least one of the battery cells of the assembled battery, and a voltage detecting line connected to a voltage detecting location at least one of the battery cells. Further the battery system fixes the connecting terminal at the voltage detecting location. The connecting terminal fixes the temperature sensor in a thermally coupling state, and electrically connects the voltage detecting line.

The temperature sensor detects the temperature of the battery cell, and inputs to the protection circuit. Therefore, the temperature sensor is connected to the protection circuit through the lead wire. In a state where the temperature of the battery cells exceeds a predetermined temperature range, the protection circuit restricts or stops the charging and discharging current of the assembled battery.

Preferably, the temperature sensor is fixed to the connecting terminal in the thermally connecting state and an insulating state. In this battery system, as one end of the temperature sensor is not connected to the electrode of the battery cell, a direct current bias by the battery cell is not applied to the temperature sensor. Therefore, a circuit configuration where the temperature sensor is connected to the protection circuit can be simplified. Here, the one end of the temperature sensor can be also connected to the electrode.

The connecting terminal is fixed to the voltage detecting location of the battery cell. The voltage detecting location can be any one of the electrode terminal of the battery cell, the bus bar connected to the electrode terminal, and the lead connected to the electrode terminal or the bus bar. The connecting terminal is connected to the electrode terminal of the battery cell directly, or to the bus bar fixed to the electrode terminal of the batter cell, to the electrode terminal through the bus bar, or to the electrode through the lead connected to the electrode terminal or the bus bar. In the connecting terminal which is directly connected to the electrode terminal of the battery cell, a terminal portion at the tip thereof is a ring terminal, and the electrode terminal is inserted into the ring terminal. In this coupling structure, for example, a male screw is provided at the surface of the electrode terminal, and a nut is screwed in the male screw to fix the ring terminal. Further, a screw hole is provided at a tip of the electrode terminal, and a stopper screw inserted in the ring terminal is screwed in the screw hole, and then the connecting terminal is connected to the electrode terminal. Further, the connecting terminal fixed to the bus bar, fixes the ring terminal to the bus bar through a stopper screw. The stopper screw is inserted in the ring terminal, and the ring terminal is fixed by screw to the bus bar, and the connecting terminal is connected to the bus bar.

Here, in this disclosure, the electrode terminal of the battery cell means a terminal which is directly or indirectly connected to the positive or negative electrode terminal of the battery cell, and has a wide meaning which includes the positive or negative battery terminal penetrating the sealing plate of the battery cell, or an external terminal connected to the positive or negative battery terminal at the outside of the battery cell.

The temperature sensor can be fixed to the connecting terminal by any one of structures of adhering, crimping, and engaging. The temperature sensor fixed by adhering is fixed to the connecting terminal in a preferable thermal connecting state. In the fixing structure of crimping or engaging, it is simply and easily fixed to the connecting terminal surely without slippage of the temperature sensor.

Preferably, the connecting terminal is a crimp terminal. The crimp terminal is made of a metal board which is capable of fixing the voltage detecting line by crimping, namely a conductive metal board which is deformed in a crimping state by a crimp tool and held in a deformed state. The crimp terminal has a coupling portion which crimps and couples the voltage detecting line and fixes the temperature sensor, and a terminal portion connected to the electrode terminal. Preferably, the terminal portion is a ring terminal, and it can be surely fixed to the electrode terminal.

The coupling portion has a groove made by bending a metal board, and comprises a connecting portion of the voltage detecting line, and a fixing portion for fixing the temperature sensor. The connecting portion crimps and connects the voltage detecting line by bending side walls of both sides thereof by a crimp tool. The fixing portion disposes the temperature sensor in the groove, and fixes the temperature sensor by filling the groove with an adhesive. This connecting structure simply and easily connects the voltage detecting line surely to the connecting terminal, and then the temperature sensor can be fixed to the connecting terminal in an ideal thermal connecting state.

In the coupling portion, the connecting portion which crimps and connects the voltage detecting line, and the fixing portion which disposes and fixes the temperature sensor in the groove, are disposed in a longitudinal direction of the coupling portion. By this structure, both of the voltage detecting line and the temperature sensor are coupled in an ideal state. Especially, this crimp terminal can crimp and connect the voltage detecting line, and disposes and surely fixes the temperature sensor in the groove. Further, in the coupling portion, the connecting portion and the fixing portion are disposed on opposite sides of an upper surface and a back surface, or a same side, and the voltage detecting line and the temperature sensor can be fixed. As the coupling portion disposes the connecting portion and the fixing portion on the opposite sides of the upper surface and the back surface, the voltage detecting line can be surely coupled by crimping, while the temperature sensor is protected from deformation force at the time of crimping the temperature sensor. Further, the coupling portion which disposes the connecting portion and the fixing portion on the same side, can simplify the structure of the crimp terminal, and the crimp terminals can be inexpensively mass-produced.

In the crimp terminal which disposes the connecting portion and the fixing portion in the longitudinal direction, the terminal portion is disposed closer to the fixing portion than the connecting portion. The temperature sensor can quickly and exactly detect the temperature of the battery cell1. It is a reason why the temperature sensor is disposed close to the electrode terminal.

The crimp terminal of the connecting terminal has the ring terminal as the terminal portion, and couples the fixing portion and the connecting portion separately in the circumferential direction at the periphery of the ring terminal. Preferably, the crimp terminal disposes the fixing portion and the connecting portion separately in the opposite locations at the periphery of the ring terminal, namely linearly. In this crimp terminal, deformation force crimping the voltage detecting line is not applied to the temperature sensor, and the voltage detecting line and the temperature sensor can be ideally fixed. Further, both of the temperature sensor and the voltage detecting line can be disposed close to the electrode terminal, and the temperature sensor can quickly and exactly detect the temperature of the battery cell.

In the connecting portion of the connecting terminal, the voltage detecting line can be connected by welding or soldering. This connecting terminal is made of a metal board, and the connecting portion and the fixing portion are connected to the terminal portion. The temperature sensor can be also connected to the fixing portion by engaging structure of the following. A coupling hole is provided at the fixing portion, and a coupling rod for inserting in the coupling hole is provided at the temperature sensor, and the temperature sensor is fixed to the fixing portion by inserting the coupling rod in the coupling hole. The connecting terminal which connects the voltage detecting line by welding or soldering can stably couple the voltage detecting line in a long time. Further, the structure where the temperature sensor is fixed to the fixing portion by inserting the coupling rod in the coupling hole, can simply fix the temperature sensor at a predetermined position.

The above battery system is installed in electric vehicles, and can supply power to a motor driving the vehicle. The battery system is installed in vehicles, and can supply power to electric equipment devices for a vehicle in parallel. Further, the above battery system is installed in electric power storage devices for storing natural energy or midnight electric power energy.

More concrete embodiments are explained below in detail, based on figures.

By using the battery cell1of a prismatic battery, the battery system100ofFIG. 1has the plurality of the prismatic batteries stacked in the longitudinal direction to configure the assembled battery10. The battery cells1are connected in series through the bus bars6. The connecting terminals2are fixed to the voltage detecting locations of the battery cells1. One end of the voltage detecting line4is connected to this connecting terminal2. The other end of the voltage detecting line4is connected to a voltage detecting circuit7, and then voltage of each of the battery cells1is inputted to the voltage detecting line7.

The voltage detecting circuit7detects the voltage of each of the battery cells1, and suppresses or stops charging or discharging current, when the voltage of the battery cell1becomes lower or higher than predetermined voltages. For example, the voltage detecting circuit7restricts or stops the charging current of the assembled battery10when the voltage of the charged battery cell1becomes more than the maximum voltage. Also, the voltage detecting circuit7restricts or stops the discharging current of the assembled battery10when the voltage of the discharging battery cell1becomes less than the minimum voltage. In this way, over charge or over discharge of the battery cell1can be prevented.

Here, the voltage detecting circuit7does not necessarily detect the voltages of all of the battery cells. It can be configured that voltages of a module or the assembled voltage10where the plural battery cells1are connected in series are detected.

Further, the battery system100ofFIG. 1has the temperature sensor3to detect temperature of the battery cells1. The temperature sensor3is connected to the connecting terminal2in a thermally coupling state to detect the temperature of the battery cells1. The connecting terminal2electrically connects the voltage detecting line4to the electrode terminals11of the battery cells1, and then couples the temperature sensor3to the electrode terminals11of the battery cells1in a thermally coupling state. The connecting terminal2is made of a metal board, and has excellent electric conductivity and thermal conductivity characteristics. Therefore, the connecting terminal2electrically connects the voltage detecting line4to the electrode terminals11in a state of low resistance, and couples the temperature sensor3in a state of quickly detecting the battery temperature. The temperature sensor3detects the temperature of the battery cells1through the connecting terminal2.

The temperature sensor3detects the temperature of the battery cells1, and inputs to the protection circuit8. Therefore, the temperature sensor3is connected to the protection circuit8through the lead wire5. In a state where the temperature of the battery cells1exceeds a predetermined temperature range, the protection circuit8restricts or stops the charging and discharging current of the assembled battery10.

As shown inFIG. 2andFIG. 3, the battery system100ofFIG. 1has the bus bars6fixed to the electrode terminals11of the battery cells1as the voltage detecting locations of the battery cells1. Therefore, the temperature sensor3detects the temperature of the battery cell1. Here, the battery system can have the electrode terminal11of the battery cell1as the voltage detecting location, namely can directly connect the connecting terminal2to the electrode terminal11. Further, the battery system, not shown in figures, may connect various electric parts, such as, for example, a shunt resistor for detecting current, a fuse, or a relay for cutting off between the electrode terminals. Therefore, a lead or the like connecting these electric parts between the electrode terminals is provided, and the connecting terminal as the voltage detecting location can be connected to the lead. Thus, the battery system can have the lead connected to the electrode terminal or the bus bar as the voltage detecting location.

The battery system100has the electrode terminal11of the battery cell1which penetrates a sealing plate of the battery cells1. Thus, the temperature inside the battery cell is conducted by the electrode terminal11to the temperature sensor3in a preferable state. Then, the temperature sensor3quickly detects the battery temperature through the connecting terminal2and the bus bar6. However, the electrode terminal does not necessarily have the structure where the electrode terminal penetrates the sealed plate of the battery cell, and then an electrode terminal as an external terminal, not shown, can be connected to a positive or negative battery terminal outside the battery cell. As such an external terminal, for example, a rod or a bolt which is coupled to the battery terminal penetrating the sealed plate through a lead member at the surface of the sealed plate, can be used. Also in the connecting terminal of the external terminal, the temperature inside the battery can be efficiently conducted to the temperature sensor.

The connecting terminal2is coupled to the temperature sensor3in a thermally coupled and insulated state, and is coupled to the voltage detecting line4in an electrically connected state. The connecting terminal2A shown inFIG. 4toFIG. 7is the crimp terminal20. The crimp terminal20is made of a metal board which can crimp and fix the voltage detecting line4. In the crimp terminal20shown in these figures, the coupling portion22connects the voltage connecting line4to the terminal portion21fixed to the electrode terminal11, and fixes the temperature sensor3. The terminal portion21is a ring terminal21A made by cutting a metal board in a ring shape, and the coupling portion22has a groove shape by bending a metal board. This crimp terminal20disposes the terminal portion21and the bottom surface of the fixing portion24in the same plane. As shown inFIG. 2andFIG. 3, the ring terminal21A is fixed to the bus bar6by a stopper screw12. The stopper screw12is inserted into the ring terminal21A, and is screwed into a screw hole6a, and fixes the terminal portion21to the bus bar6. Here, the bus bar does not necessarily have the screw hole. Instead, a through hole is opened at a fixing location of the connecting terminal in the bus bar, and a tip of a stopper screw inserted into the through hole is screwed into a nut at the rear surface of the bus bar, and then the connecting terminal can be fixed by the screw. Further, the connecting terminal can be welded to the bus bar. In the case of welding the bus bar to the connecting terminal, it is not necessary to provide a hole in the bus bar or the connecting terminal for fixing the connecting terminal.

The coupling portion22disposes the fixing portion24fixing the temperature sensor3and the connecting portion23connecting the voltage detecting line4in the longitudinal direction, and disposes the fixing portion24at the near side to the terminal portion21. The connecting terminal2A disposing the fixing portion24at the terminal portion21side, can dispose the temperature sensor3close to the electrode terminal11, and then the temperature sensor3can quickly detect the temperature of the battery cell1.

The fixing portion24has a groove shape, and the temperature sensor3is disposed in the groove27, and the groove27is filled up with an adhesive17. The lead wire5of the temperature sensor3is led outside from the fixing portion24. The adhesive17has thermal conductivity properties and insulating properties, and by this, the temperature sensor3is fixed to the fixing portion24in a thermally coupling and insulating state. As such an adhesive, for example, epoxy resin or the like can be used. Especially, the adhesive of epoxy resin has a strong adhesive strength to a metal, and its hardening speed is high, and then while working efficiency can be improved, it is surely adhered. Here, the adhesive other than epoxy resin can be used. Preferably, the adhesive can be mixed with members having high thermal conductivity. As such a member for mixing, for example, powder such as silica, alumina, or the like can be used.

The fixing portion24shown inFIG. 5andFIG. 6has an air releasing hole31at the low end in the middle portion of the side wall26at the bottom surface of the groove27. By this structure, when the adhesive17is injected in the groove27, the adhesive17can be smoothly injected while air is released through the air releasing hole31. The air releasing hole31shown in the figure is opened in the middle portion at the boundary between the bottom surface30and the side wall26of the groove27, but the air releasing holes can be provided in the middle portion or the like at the bottom surface or the side wall. The opening area, the number, and the location of the releasing holes31are decided considering a viscosity and a hardening speed of the filling adhesive17. However, the air releasing hole is not necessarily provided.

The connecting portion23disposes a core wire4A of the voltage detecting line4inside the groove, and both side walls25of the groove crimp the core wire4A by bending both side walls25, and then voltage detecting line4is electrically connected. The connecting terminal2A shown in the figures disposes the fixing portion24and the connecting portion23respectively on the upper surface and the back surface of the coupling portion22(on the opposite sides in the figure). InFIG. 4toFIG. 7, the fixing portion24is disposed at the upper side, and the connecting portion23is disposed at the back side. The coupling portion22disposes the side walls26of the fixing portion24at the upper side and the side walls25of the connecting portion23at the back side of the bottom surface. The connecting terminal2A disposes the temperature sensor3in the groove27of the fixing portion24having the groove shape opening upward, and this portion is filled with the adhesive17, and the temperature sensor3is fixed by hardening the adhesive17. Further, the connecting terminal2A disposes the core wire4A in the connecting portion23having the groove shape opening downward, and both side walls25are deformed and bent by a crimp tool (not shown), and the voltage detecting line4is crimped and fixed. As this crimp terminal20disposes on the opposite sides and separates the side walls25of the connecting portion23and the side walls26of the fixing portion24, excessive force is not applied to the temperature sensor3in the process where the voltage detecting line4is connected through deforming the side walls25of the connecting portion23by the crimp tool. Thus, the temperature sensor3can be fixed to the fixing portion24while being protected. Further, by disposing those, the lead wire5connected to the temperature sensor3and the connecting portion23do not interfere with each other.

Additionally, as shown by a dotted line inFIG. 5andFIG. 6, the connecting portion23can have second side walls32for crimping an insulating coating portion4B of the voltage detecting line4outside the side walls25. This connecting portion23extends the bottom surface30of the connecting portion23in the direction where the voltage detecting line4is led out, and provides the second side walls32at both sides of this extended portion to form a groove shape. This connecting portion23deforms the side walls25, and crimps and fixes the core wire4A of the voltage detecting line4, and deforms the second walls32, and crimps and fixes the insulating coating portion4B. In this structure, as the insulating coating portion4B of the voltage detecting line4is held by the connecting portion23, this structure effectively prevents applying mechanical force to the core wire4A, and disconnection of lines or contact failure is prevented, and then it can be safely used in a long time.

The connecting terminal2B shown inFIG. 8toFIG. 10disposes the fixing portion24and the connecting portion23on the same side, namely on the upper surface in the figures. The side walls26of the fixing portion24and the side walls25of the connecting portion23are separated from each other by providing a cutting line28at the boundary therebetween. As the coupling portion22separates the side walls26of the fixing portion24and the side walls25of the connecting portion23from each other by the cutting line28, excessive force is not applied to the temperature sensor3without the side wall26of the fixing portion24deformed in a state where the side walls25of the connecting portion23are crimped. Additionally, as shown by a dotted line inFIG. 9andFIG. 10, also in this connecting terminal, second side walls32for crimping the insulating coating portion4B of the voltage detecting line4can be provided outside the side walls25. This connecting portion23also deforms the side walls25, and crimps and fixes the core wire4A of the voltage detecting line4, and deforms the second walls32, and crimps and fixes the insulating coating portion4B.

However, as shown inFIG. 11toFIG. 13, the side walls25of the connecting portion23and the side walls26of the fixing portion24can be continuously formed without the cutting line. In this crimp terminal20, when the side walls25of the connecting portion23for crimping is deformed, the side walls26of the fixing portion24continuously formed to this are deformed at the boundary to the connecting portion23. The deformed side walls26make the opening portion of the groove shape narrow, and prevent slippage of the temperature sensor3. This connecting terminal2C temporarily fixes the lead wire5of the temperature sensor3by the side walls25of the connecting portion23for fixing the voltage detecting line4. The temperature sensor3temporarily fixed by the side walls25of the connecting portion23uses the lead wire5of which the surface is covered with insulating coating. The lead wire5is insulated from the connecting portion23by the insulating coating, and is led outside. In the process where the lead wire5of the temperature sensor3is temporarily fixed by the side walls25of the connecting portion23, the groove27is filled with the adhesive17to fix the temperature sensor3, in a state where the lead wire5is temporarily fixed without the groove27of the fixing portion24filled with the adhesive17.

The connecting terminal2D ofFIG. 14toFIG. 15is a crimp terminal20, and the connecting portion23is disposed at the terminal side. This connecting terminal2D disposes the connecting portion23and the fixing portion24at the same side, namely at the upper side of the coupling portion22. The connecting portion23and the fixing portion24disposed at the same side are separated from each other by providing the cutting line28at the boundary therebetween so as not to apply excessive force to the temperature sensor3in the process of crimping. In this connecting terminal2D, after the core wire4A of the voltage detecting line4is crimped by the side walls25of the connecting portion23, the temperature sensor3is disposed in the groove27of the fixing portion24, and the groove27is filled with the adhesive17to fix the temperature sensor3. The adhesive17which fixes the temperature sensor3by burying it, fixes also the voltage detecting line4together. Thus, this connecting terminal2D can surly fixes both the temperature sensor3and the voltage detecting line4by the adhesive17. The connecting terminal2D of the figures disposes the connecting portion23and the fixing portion24at the same side (the upper side in the figures), but the connecting terminal can also dispose the connecting portion and the fixing portion at the opposite sides.

Further, the connecting terminal2E ofFIG. 17toFIG. 19has the ring terminal21A of the terminal portion21, and couples the fixing portion24and the connecting portion23separately in the facing locations at the periphery of the ring terminal21A. The connecting terminal2E of this structure fixes the voltage detecting line4and the temperature sensor3independently, separately. The voltage detecting line4is fixed such that the core wire4A is crimped by the side walls25of the connecting portion23, and the temperature sensor3is buried in the adhesive17with which a space between the side walls26of the fixing portion24is filled, and is fixed. The connecting terminal2where the fixing portion24and the connecting portion23are provided at the periphery of the ring terminal21A, can disposes the fixing portion24and the connecting portion23at a predetermined angle, and the lead wire5of the temperature sensor3and the voltage detecting line4can be led out in the appropriate directions. Further, the side walls25of the connecting portion23and the side walls26of the fixing portion24can be also disposed at the opposite sides, and then the voltage detecting line4and the lead wire5can be disposed at the upper side and the lower side. The connecting terminal2E of the figures disposes the connecting portion23and the fixing portion24at the same side (the upper side in the figures), but the connecting terminal can also dispose the connecting portion and the fixing portion at the opposite sides.

The connecting terminal2F ofFIG. 20toFIG. 22electrically connects the voltage detecting line4by welding or soldering without crimping the voltage detecting line4. This connecting terminal2F provides the coupling portion22having a groove shape at the terminal portion21, and the core wire4A of the voltage detecting line4is electrically connected by welding or soldering at the rear end portion of the connecting portion22, and the temperature sensor3is fixed to the tip portion of the connecting portion22, namely at the terminal portion21side of the connecting portion22. After the wire core4A of the voltage detecting line4is electrically connected to the coupling portion22by welding or soldering, the temperature sensor3is disposed in the groove27of the coupling portion22, and the groove27is filled with the adhesive17to fix the temperature sensor3. This connecting terminal2D can electrically connects the voltage detecting line4to the coupling portion22by welding or soldering surly and stably in a state of low resistance, and a part of the voltage detecting line4can be surely fixed by the adhesive17burying the temperature sensor3. Further, as shown inFIG. 20andFIG. 22by using cross-hatched dotted lines, the adhesive17with which the coupling portion22is filled is extended to the insulating coating portion4B of the voltage detecting line4, and the insulating coating portion4B of the voltage detecting line4and the lead wire5of the temperature sensor3can be buried in the adhesive integrally. In this structure, as the insulating coating portion4B of the voltage detecting line4and the lead wire5of the temperature sensor3can be fixed in the adhesive integrally, it is reduced that mechanical force is applied to the core wire4A, and disconnection of lines or contact failure is effectively prevented.

As shown inFIG. 23, the connecting terminal2where the voltage detecting line4is electrically connected to the coupling portion22by welding or soldering, can have a structure where the connecting portion23and the fixing portion24are separately provided at the periphery of the ring terminal21A. In this connecting terminal2G, the connecting portion23which is connected to the voltage detecting line4by welding or soldering, can be disposed away from the fixing portion where the temperature sensor3is fixed. Therefore, in a state where the temperature sensor3is fixed, even though the voltage detecting line4is welded or soldered, it is prevented that the temperature sensor3is heated by the heat of welding or soldering.

Further, the connecting terminal2H shown inFIG. 24andFIG. 25has plane shapes of the terminal portion21and the coupling portion22. The coupling portion22of the plane shape fixes the temperature sensor3to the terminal side, and the voltage detecting line4at the rear end portion. The plane shape of the bottom surface in the temperature sensor3tightly contacts, and is fixed to the surface of the coupling portion22. The temperature sensor3is fixed to the coupling portion22with its peripheral portion screwed by the stopper screws13, or is fixed by adhering. The voltage detecting line4is electrically connected to the coupling portion22with the core wire4A soldered or welded. After the voltage detecting line4is electrically connected, the connecting terminal2H fixes the temperature sensor3, and then it prevents the temperature sensor3from being heated by soldering or welding.

Further, in the connecting terminal, the surface mount type thermistor, not shown, can be connected to or mounted on the wiring pattern. This wiring pattern is made by the following steps. An insulating layer made from a paste is coated on the surface of the terminal portion and coupling portion, and its surface is plated with a metal layer, and then the wiring pattern is made by etching. In this connecting terminal, the lead wire is connected by soldering to the wiring pattern which is led from a connecting portion of the thermistor. Then, the voltage detecting line is connected by soldering or welding to the surface of the coupling portion which is not coated with the insulating layer.

The connecting terminal21shown inFIG. 26andFIG. 27provides a coupling hole29at the fixing portion24where the temperature sensor3is fixed. In this fixing portion24, a coupling rod19of an under cut shape provided at the temperature sensor3, is inserted into the coupling hole29, and then the temperature sensor3is fixed. To fix the temperature sensor3and the fixing portion24in a preferable thermal coupling state, the surface of the fixing portion24which contacts the temperature sensor3is a plane shape, and the facing surface of the temperature sensor3to the fixing portion24is a plane shape. The coupling rod19projects in the direction perpendicular to the facing surface. In this coupling structure, the coupling rod19is inserted into the coupling hole29, and then the temperature sensor3tightly contacts the fixing portion24in a surface contact state. The connecting terminal21of these figures crimps, connects the voltage detecting line4to the connecting portion23.

Further, the connecting terminal2J shown inFIG. 28toFIG. 30crimps, fixes the temperature sensor3to the fixing portion24. This connecting terminal2J disposes the fixing portion24and the connecting portion23in the longitudinal direction at the coupling portion22, and fixes the temperature sensor3to the fixing portion24, and connects the voltage detecting line4to the connecting portion23. The fixing portion24and the connecting portion23provide the side walls26,25projecting in the front and back opposite directions (the upper and down opposite directions in the futures). In the coupling portion22shown in the figures, the side walls26of the fixing portion24project upward, and the side walls25of the connecting portion25project downward. As shown in a sectional view ofFIG. 30, the side walls26of the fixing portion24fix the temperature sensor3in a crimp state by deforming those so as to bend inward. As shown in the sectional view ofFIG. 30, the side walls25of the connecting portion23crimp, electrically connect the core wire4A of the voltage detecting line4. This connecting terminal2J can fix the temperature sensor3surely in a thermal coupling state in a long time. In this fixing structure, a space between the temperature sensor3and the fixing portion24is filled with the adhesive17having a thermal conductivity, and then it can improve the thermal coupling state between the temperature sensor3and the fixing portion24.

Here, as the temperature sensor disposed at the fixing portion in this structure, the following type is preferable. After a thermistor element connected to the lead wire is immersed in resin in a fusion state, it is dried. It is a reason why a connecting section between the thermistor element and the lead wire is covered with insulating resin. In this temperature sensor, the connecting section between the thermistor element and the lead wire is not exposed outside, and is an insulating structure against the outside, and then the temperature sensor can be disposed at the connecting terminal while surely preventing short circuit to the voltage detecting line.

In the above connecting terminal2, for example, after a sheet of a metal board is cut in a predetermined shape, the fixing portion24or the connecting portion23is formed by bending process. One example of such a cutting pattern40of the metal board is shown inFIG. 31. In the cutting pattern40of the metal board shown in this figure, the terminal portion21is coupled to one short side of a rectangle as the bottom surface20of the coupling portion22, and the side walls26and the side walls25are coupled to both long sides of the rectangle, facing each other. The cutting lines28are provided between the side walls26and the side walls25which are adjacent to each other. Further, bending boards33are coupled to the pair of the side walls26at one end of the terminal portion21side. The through holes of the air releasing holes31are opened in the middle portions at the boundary between the bottom surface30of the rectangle and the side walls26.

The connecting terminal2is formed from the above cutting pattern40in the following way.(1) The bottom surface30of the rectangle and the side walls26of both sides are bent along bending lines34at the boundary therebetween in a predetermined direction (for example, a valley fold), and then the groove27is formed between the facing side walls26.(2) The bottom surface30of the rectangle and the side walls25of both sides are bent along bending lines35at the boundary therebetween in a predetermined direction. When the side walls25are bent in the same direction (a valley fold) as the side walls26, the fixing portion24and the connecting portion23are formed at the same side among the front or the back. When the side walls25are bent in the opposite direction (a mountain fold) to the side walls26, the fixing portion24and the connecting portion23are formed at the opposite sides among the front or the back.(3) The bending boards33of the side walls26bent to the bottom surface30are bent inward (a valley fold) along bending line36, and then an opening portion of the groove27as the fixing portion24is closed. In this structure, the bending boards33effectively prevent the adhesive with which the groove27of the fixing portion24is filled from flowing out.

Here, preferably, in the above cutting pattern40, the plural pieces are continuously coupled in a state of members of a reel shape, and bending along the bending lines34,36is carried out in a step, and by bending along the bending lines35, the side walls25crimp the voltage detecting line4in another step. Then, after the temperature sensor3is fixed to the fixing portion24by the adhesive17, the connecting terminal2is cut off from the members of the reel shape. Instead, after the connecting terminal2is cut off from the members of the reel shape, the temperature sensor3is fixed to the fixing portion24by the adhesive17. By such a manufacturing method, manufacturing processes can be automated, and then manufacturing cost can be reduced.

The above battery system can be used as a power source for a vehicle. As the vehicle incorporating the battery system, electric vehicles such as hybrid cars or plug-in hybrid cars that are driven by both an engine and an electric motor, or pure electric vehicles that are driven only by an electric motor, can be used. The battery system is used as power sources of these vehicles.

INDUSTRIAL APPLICABILITY

The battery system of the present invention can be suitably used in electric vehicles such as pure electric vehicles, hybrid electric vehicles, or the like, or electric power storage devices for storing natural energy such as solar cell power generation or wind power generation, or midnight electric power energy.