JP7014030B2 - Vehicle power storage device - Google Patents

Description

The present invention relates to a vehicle power storage device mounted on a vehicle.

In recent years, it has been studied to replace a lead-acid battery with a lead-free lithium-ion secondary battery as a storage battery constituting a power storage device for auxiliary equipment mounted on a vehicle. Lithium-ion secondary batteries can be made smaller and lighter than lead-acid batteries with the same storage capacity, which contributes to weight reduction and improved running performance of vehicles.

For example, a square lithium-ion secondary battery is configured by enclosing a positive and negative electrode plate and an electrolytic solution in a rectangular parallelepiped case made of an aluminum alloy in a sealed manner, and has a certain degree of impact resistance. Then, a power storage device for auxiliary equipment is configured by a plurality of square lithium ion secondary batteries and arranged in the engine room.

The power storage device for auxiliary equipment arranged in the engine room is exposed to the air warmed by the heat of the engine during running, and drops to the outside air temperature when it is cold. The lithium-ion secondary battery constituting the power storage device has an operating temperature range in which its excellent performance can be exhibited, and charging / discharging outside this operating temperature range may not only exhibit its performance but also cause deterioration. Therefore, it is necessary to make the power storage device for auxiliary equipment less susceptible to the heat of the engine. Further, when the outside air temperature is lower than the lower limit temperature in the operating temperature range, it is necessary to heat the power storage device for auxiliary equipment so as to maintain the temperature within the operating temperature range.

As a technique for heating a power storage device, for example, as in Patent Document 1, a technique for heating by a heater arranged on the bottom side of an aggregate of square storage batteries is known. Further, as in Patent Document 2, a technique is known in which a sheet-shaped heater is arranged between laminated type storage batteries in which positive electrode plates and negative electrode plates are alternately stacked via a separator and sealed with an insulating film.

Japanese Unexamined Patent Publication No. 2008-103207 Japanese Patent No. 56099799

When heating a power storage device composed of a square storage battery, the heater is arranged so as to be close to or in contact with the case as in Patent Document 1, and Joule heat generated by energization is transmitted to the case to heat the storage battery. It is difficult to efficiently heat the electrode plate as in Patent Document 2. Specifically, since there is a heat capacity of a case other than the electrode plate, the heat of the heater is used for other than heating the positive and negative electrode plates.

It is also conceivable to cover the power storage device with a heat insulating member together with the heater in order not to let the heat of the heater escape and to prevent the influence of the heat from the engine, but since the heater heats from a predetermined surface of the case, the electrode plate is uniform. It was difficult to heat up, and there was room for improvement in heating the storage battery.

An object of the present invention is to provide a vehicle power storage device capable of efficiently heating a storage battery.

The invention of claim 1 is a vehicle power storage device including a plurality of storage batteries having a rectangular parallelepiped-shaped case, wherein the positive and negative plates of the storage battery are wound flatly through a separator and are parallel to each other. A winding body having a rectangular parallelepiped portion and an insulating heat insulating member covering the outer periphery of the winding body are housed in the case, and between at least one rectangular parallelepiped portion of the winding body and the heat insulating member. Is provided with a heater that abuts on the flat surface portion via an insulating member , the insulating member covers the outer periphery of the winding body inside the heat insulating member, and the heater is housed in a region in contact with the flat surface portion. It is characterized by having a bag-shaped housing for the purpose .
According to the above configuration, the heater heats the winding body from a wide eccentric surface portion without passing through the case, and the heat insulating member makes it difficult to transfer the heat of the heater to the case, so that the heating can be efficiently performed. Further, by accommodating the heater in the accommodating portion formed of the insulating member that insulates the winding body and the heater, the heater can be easily fixed to the eccentric surface portion of the winding body.

The invention of claim 2 is a vehicle power storage device including a plurality of storage batteries having a rectangular parallelepiped-shaped case. In the storage battery, a positive electrode plate and a negative electrode plate are wound flatly through a separator and a pair is parallel to each other. A winding body having a rectangular parallelepiped portion and an insulating heat insulating member covering the outer periphery of the winding body are housed in the case, and between at least one rectangular parallelepiped portion of the winding body and the heat insulating member. The heat insulating member is provided with a heater that abuts on the flat surface portion via an insulating member, and the heat insulating member has a bag shape for accommodating the heater formed by adhering an insulating sheet member to a region in contact with the flat surface portion. It is characterized by having a housing.
According to the above configuration, the heater heats the winding body from a wide eccentric surface portion without passing through the case, and the heat insulating member makes it difficult to transfer the heat of the heater to the case, so that the heating can be efficiently performed. Further, the heater is accommodated in the accommodating portion formed by the insulating sheet member in the heat insulating member covering the outer peripheral portion of the winding body, and the outer peripheral portion of the winding body is covered so that the accommodating portion abuts on the eccentric flat portion of the winding body. As a result, the winding body and the heater can be insulated, and the heater can be easily fixed to the eccentric surface portion of the winding body.

The invention of claim 3 is the invention of claim 1 or 2 , wherein the heater is connected to the positive electrode terminal and the negative electrode terminal of the storage battery and is operated by the electric power of the storage battery, and the operation and non-operation of the heater are predetermined. It is characterized by being equipped with a temperature switch that switches according to the switching temperature.
According to the above configuration, the storage battery itself can maintain a temperature equal to or higher than a predetermined switching temperature, so that the temperature suitable for use of the storage battery is maintained even while the vehicle is parked in an environment where the outside air temperature is low, and charging / discharging is performed. It is possible to maintain the possible state.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the resistance value of the heater is set so as to be maintained at the switching temperature by the heat generated by the heater and the self-heating of the storage battery when the heater is operated. It is a feature.
According to the above configuration, it is possible to minimize the power consumption and moderate the decrease in the SOC of the storage battery.

According to the vehicle power storage device of the present invention, the storage battery can be efficiently heated.

It is a block diagram explaining the structure of the vehicle by embodiment of this invention. FIG. 3 is an exploded perspective view of a main part of a power storage device according to an embodiment of the present invention. FIG. 3 is an exploded perspective view of a main part of a storage battery according to an embodiment of the present invention. FIG. 3 is a sectional view taken along line IV-IV of FIG. It is a main part development perspective view which shows one example of the accommodating part. It is the main part development perspective view which shows the other example of the accommodation part. It is a figure which shows the temperature change of the storage battery placed in a low temperature environment.

Hereinafter, a vehicle power storage device according to an embodiment of the present invention will be described. First, the overall configuration of the vehicle will be described with reference to FIG.
The vehicle has an engine 2 for driving the vehicle as a vehicle drive device 1, a starter motor 4 for starting the engine 2 as an auxiliary device 3, a blower fan 5 for sending outside air to the engine room, and the driving force of the engine 2. It is equipped with various sensors including an alternator 6 and a temperature sensor 7 that are used to generate power. Further, in the engine room, a power storage device 10 (vehicle power storage device) for storing electric power to be supplied to the engine 2, auxiliary equipment 3, and the like is provided. The vehicle is equipped with a control unit (ECU 8) that controls the engine 2, the auxiliary equipment 3, the power storage device 10, and the like.

The ECU 8 is composed of a computer including a CPU, a memory for storing various programs, an input / output device, and the like. The ECU 8 processes signals periodically output from various sensors, and outputs control signals for appropriately operating the engine 2, the blower fan 5, the power storage device 10, and the like. The ECU 8 manages the state of charge (SOC) of the power storage device 10 and drives the alternator 6 to charge the alternator 6 so as not to interfere with traveling.

Next, the power storage device 10 will be described.
The power storage device 10 is arranged in the engine room of the vehicle accommodating the engine 2. The engine 2 is cooled by, for example, a water-cooled cooling mechanism (not shown), but the heat released from the engine 2 warms the air in the engine room. This air is discharged to the outside together with the running wind and the outside air introduced into the engine room by the blower fan 5. The temperature sensor 7 detects the surface temperature of the power storage device 10 or a temperature in the vicinity thereof and outputs temperature data to the ECU 8, and the ECU 8 drives a blower fan 5 to prevent an excessive temperature rise of the power storage device 10. Adjust the air volume.

The power storage device 10 is configured to connect a plurality of square lithium ion secondary batteries (storage batteries 21) in series to supply electric power to the auxiliary equipment 3 and the like. For example, as shown in FIG. 2, the power storage device 10 maintains a pair of support members 11 so that the four storage batteries 21 maintain a state of being closely aligned in a row with an insulating separator 13 sandwiched between them. And a pair of end plates 12 are connected to each other. These storage batteries 21 are connected in series by a plurality of bus bars 14, and are provided with positive electrode terminals 15 and negative electrode terminals 16 of the power storage device 10 at both ends thereof.

Next, the storage battery 21 will be described with reference to FIGS. 3 to 5.
The storage battery 21 has a rectangular parallelepiped case 22, and a positive electrode terminal 23 and a negative electrode terminal 24 of the storage battery 21 are arranged on an upper surface portion 22a which is a lid member. The case 22 has a first side surface portion 22b and a second side surface portion 22c having the maximum side surface area parallel to each other, and a third side surface portion 22d orthogonal to and parallel to the first and second side surface portions 22b and 22c. It also has a fourth side surface portion 22e and a bottom surface portion 22f facing the upper surface portion 22a. In this case 22, the positive electrode plate 30c and the negative electrode plate 30d are wound flat around the horizontal axis via a porous separator (first separator 30a, second separator 30b), and the outer periphery thereof is formed with an insulating member 33. The winding body 30 covered with the heat insulating member 34 and the electrolytic solution (not shown) are housed and sealed with a lid member.

In the end region of one of the winding bodies 30 in the horizontal axis direction (for example, the third side surface portion 22d side of the case 22), the positive electrode current collecting tab 31 connected to the positive electrode plate 30c extends upward and the positive electrode terminal in the case 22. It is connected to 23. In the other end region (fourth side surface portion 22e side) of the winding body 30 in the horizontal axis direction, the negative electrode current collecting tab 32 connected to the negative electrode plate 30d extends upward and is connected to the negative electrode terminal 24 in the case 22. ing. Further, the winding body 30 has a pair of flat and substantially parallel flat plane portions occupying a wide area of the outer peripheral portion thereof on the first side surface portion 22b side and the second side surface portion 22c side.

The insulating member 33 that covers the outer periphery of the winding body 30 is made of a synthetic resin material (for example, polypropylene or polyethylene) and is formed in a flexible sheet shape. In the winding body 30 covered with the insulating member 33, at least a majority region of the outer periphery thereof is covered with the sheet-shaped heat insulating member 34, and both ends in the horizontal axial direction may also be covered with the insulating member 33. A region between the heat insulating member 34 and the insulating member 33 and close to at least one uneven flat surface portion (for example, the flat surface portion on the first side surface portion 22b side) of the winding body 30 is wound from the uneven flat surface portion. A sheet-shaped heater 35 for heating the rotating body 30 is arranged.

The heater 35 is configured to generate Joule heat when energized, and a pair of power lines 35a and 35b are connected to the positive electrode terminal 23 and the negative electrode terminal 24 of the storage battery 21, respectively. The power line 35a is connected to the positive electrode terminal 23 via a temperature switch 25 arranged on the upper surface portion 22a. The temperature switch 25 is switched so as to be energized at a temperature lower than a predetermined temperature, and operates by detecting the temperature of the upper surface portion 22a or the temperature inside the case 22 as the temperature of the storage battery 21. As a result, the storage battery 21 operates the heater 35 by the electric power stored in itself to maintain a predetermined temperature. The predetermined temperature is, for example, −20 ° C., and is appropriately set according to the specifications of the storage battery 21 (lower limit value in the operating temperature range).

The resistance value of the heater 35 is set so that the winding body 30 covered with the heat insulating member 34 can maintain a predetermined temperature by the Joule heat and the self-heating of the storage battery 21 that supplies electric power when the heater 35 is operated. .. For example, in order for the storage battery 21 to maintain −20 ° C. in an environment of −30 ° C., the resistance value of the heater 35 is set so that the amount of heat generated by the heater 35 and the amount of heat dissipated from the case 22 are balanced. Since the amount of heat radiation varies depending on the specifications of the storage battery 21, this resistance value is appropriately set according to the specifications of the storage battery 21. As a result, the power consumption of the heater 35 is minimized, and the decrease in SOC is moderated.

The heat insulating member 34 is formed by forming, for example, a silica airgel-based porous hollow structure into a flexible sheet shape so that the hollow structure is closed to the outside, and the wound body 30 is more than the insulating member 33. It has a high effect of suppressing heat conduction between the cases 22, and has insulating properties without infiltration of the electrolytic solution. The insulating member 33 that covers the outer periphery of the winding body 30 has an insulating sheet member made of synthetic resin in a region that abuts on at least one uneven flat surface portion (for example, the uneven flat surface portion on the first side surface portion 22b side) of the winding body 30. It is provided with a bag-shaped accommodating portion 33a formed by bonding. The heater 35 is housed in the housing portion 33a in a sealed manner, and the heater 35 does not come into direct contact with the electrolytic solution and the winding body 30. The power lines 35a and 35b of the heater 35 extend to the outside of the accommodating portion 33a and are connected to the positive electrode terminal 23 and the negative electrode terminal 24, respectively.

As shown in FIG. 6, instead of the accommodating portion 33a, the heat insulating member 34 adheres the insulating sheet member made of synthetic resin to the region of the winding body 30 close to the inclined flat portion on the first side surface portion 22b side, for example. It is also possible to form a bag-shaped accommodating portion 34a, and accommodate the heater 35 in the accommodating portion 34a and seal it. Further, although not shown, the heater 35 sandwiched between the insulating sheet members made of synthetic resin and sealed is arranged in a region close to the eccentric surface portion on the first side surface portion 22b side, and covered with the heat insulating member 34, for example. Can also be held. In these cases, the insulating member 33 may be omitted.

Based on the temperature data of the temperature sensor 7, the ECU 8 controls cooling by the blower fan 5 so that the power storage device 10 can exhibit its performance within a predetermined operating temperature range of the power storage device 10. For example, when the temperature sensor 7 detects a temperature equal to or higher than the upper limit temperature in the operating temperature range (for example, 60 ° C.) or is predicted to exceed the upper limit temperature from the rising mode of the detected temperature, the upper limit temperature in the operating temperature range is used. The blower fan 5 is operated to maintain a low temperature, or the amount of blown air thereof is increased. Since the winding body 30 of the storage battery 21 is covered with the heat insulating member 34, the influence of the temporary temperature rise in the surroundings is reduced.

On the other hand, the temperature switch 25 energizes the heater 35 when the temperature of the storage battery 21 becomes lower than the lower limit temperature in the operating temperature range (for example, −20 ° C.), and the heater 35 maintains at least the lower limit temperature in the operating temperature range. Works. In FIG. 7, the conventional storage battery and the storage battery 21 which are equivalent to the storage battery 21 except that they are not provided with the temperature switch 25, the heat insulating member 34, and the heater 35 are placed in an environment where the outside air temperature is -30 ° C from the state of 25 ° C, respectively. It shows the change in temperature at the time. As shown by the broken line, the conventional storage battery is not suitable for use by lowering the temperature to the lower limit temperature of -20 ° C in the operating temperature range in about 1.7 hours and then lowering to the outside air temperature of -30 ° C. .. On the other hand, as shown by the solid line, the storage battery 21 takes about 3 hours to cool down to −20 ° C., which is the lower limit temperature of the operating temperature range, which is longer than that of the conventional storage battery. The lower limit temperature of is maintained.

Next, the operation and effect of the present invention will be described.
The power storage device 10 arranged in the engine room is composed of a plurality of storage batteries 21. Each storage battery 21 houses the wound body 30 covered with the insulating member 33 covered with the heat insulating member 34 in the rectangular parallelepiped case 22. A sheet-shaped heater 35 for heating the winding body 30 is disposed between the insulating member 33 and the heat insulating member 34. Therefore, the heat insulating member 34 suppresses the temperature rise of the winding body 30 due to the air heated by the heat of the engine 2, and when the heater 35 heats the winding body 30 in a low temperature environment, the wide flat surface portion does not go through the case 22. The winding body 30 is uniformly heated, and the heat insulating member 34 makes it difficult to transfer the heat of the heater 35 to the case 22, so that the heating can be performed efficiently.

The heater 35 is connected to the positive electrode terminal 23 and the negative electrode terminal 24 of the storage battery 21 and is operated by the electric power of the storage battery 21. Since the temperature switch 25 for switching between the operation and non-operation of the heater 35 at a predetermined switching temperature is provided, the storage battery 21 itself can maintain a temperature equal to or higher than the predetermined switching temperature. Therefore, even while the storage battery 21 is parked in an environment where the outside air temperature is lower than the operating temperature range of the storage battery 21, the temperature within the operating temperature range can be maintained to maintain a chargeable / dischargeable state.

Moreover, since the resistance value of the heater 35 is set so as to be maintained at the switching temperature by the heat generated by the heater 35 and the self-heating of the storage battery 21 when the heater 35 is operated, the power consumption by the heater 35 is minimized and the storage battery 21 is used. The decrease in SOC can be moderated.

Since the insulating member 33 covers the outer periphery of the winding body 30 and includes a bag-shaped accommodating portion 33a for accommodating the heater 35 in a region close to the eccentric surface portion of the winding body 30, the accommodating portion 33a is provided. By accommodating the heater 35, the heater 35 can be easily fixed to the flat surface portion of the winding body 30.

When a bag-shaped accommodating portion 34a formed by adhering an insulating film to a region close to the flat surface portion of the winding body 30 of the heat insulating member 34 is provided, the heater 35 is accommodated in the accommodating portion 34a. The heater 35 can be easily fixed to the uneven flat surface portion of the winding body 30.

In a storage battery using a winding body wound around a vertical axis center instead of a winding body 30 wound around a horizontal axis center, or an electrode body in which positive and negative electrode plates are alternately laminated via a separator. , Can be configured in the same way. Further, although the power storage device 10 for auxiliary equipment arranged in the engine room has been described, it can also be configured as a vehicle drive power storage device that supplies electric power to a drive motor of a hybrid vehicle or an electric vehicle, for example. In addition, a person skilled in the art can carry out the embodiment in which various modifications are added to the above embodiment without departing from the spirit of the present invention, and the present invention also includes such modifications.

1: Vehicle drive device 2: Engine 3: Auxiliary equipment 7: Temperature sensor 8: ECU
10: Power storage device 21: Storage battery 22: Case 22b: First side surface portion 22c: Second side surface portion 23: Positive electrode terminal 24: Negative electrode terminal 25: Temperature switch 30: Winding body 30a: First separator 30b: Second separator 30c : Positive electrode plate 30d: Negative electrode plate 33: Insulating member 33a: Accommodating portion 34: Insulating member 34a: Accommodating portion 35: Heaters 35a, 35b: Power supply line

Claims (4)

In a vehicle power storage device equipped with multiple storage batteries having a rectangular parallelepiped case,
The storage battery includes a winding body in which a positive electrode plate and a negative electrode plate are wound flatly via a separator and has a pair of parallel flat surface portions, and an insulating heat insulating member that covers the outer periphery of the winding body. Is housed in the case,
A heater that abuts on the eccentric surface portion via the insulating member is provided between the eccentric surface portion of at least one of the winding bodies and the heat insulating member .
The insulating member covers the outer periphery of the winding body inside the heat insulating member, and is provided with a bag-shaped accommodating portion for accommodating the heater in a region in contact with the eccentric surface portion . Power storage device. In a vehicle power storage device equipped with multiple storage batteries having a rectangular parallelepiped case,
The storage battery includes a winding body in which a positive electrode plate and a negative electrode plate are wound flatly via a separator and has a pair of parallel flat surface portions, and an insulating heat insulating member that covers the outer periphery of the winding body. Is housed in the case,
A heater that abuts on the eccentric surface portion via the insulating member is provided between the eccentric surface portion of at least one of the winding bodies and the heat insulating member.
The heat insulating member is a vehicle power storage device including a bag-shaped accommodating portion for accommodating the heater formed by adhering an insulating sheet member to a region in contact with the inclined flat surface portion . The heater is characterized by comprising a temperature switch which is connected to a positive electrode terminal and a negative electrode terminal of the storage battery and is operated by the electric power of the storage battery to switch between operation and non-operation of the heater at a predetermined switching temperature. The vehicle power storage device according to 1 or 2 . The vehicle power storage device according to claim 3 , wherein the heater has a resistance value set so as to be maintained at the switching temperature by the heat generated by the heater and the self-heating of the storage battery when the heater is operated .

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