JP2018160419A - Battery case and battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery case capable of warming a storage battery when temperature of the storage battery is likely to be lower than an appropriate range, capable of preventing the temperature of the storage battery from rising when the temperature of the storage battery is likely to be higher than the appropriate range, so as to be capable of keeping the temperature of the storage battery in the appropriate range.SOLUTION: The battery case for accommodating a storage battery for supplying electric power to a vehicle drive motor is made of a resin containing a heat storage material.SELECTED DRAWING: Figure 1

Description

The present invention relates to a battery case for storing a storage battery for driving a running motor provided in a vehicle, and a battery using the battery case.

Conventionally, automobiles mainly use engines that use gasoline or light oil as fuel. However, an automobile using an engine as a power source emits harmful gases such as exhaust gas containing carbon dioxide and the like, and thus has a large environmental load. On the other hand, as automobiles with reduced environmental loads, electric vehicles powered by motors (hereinafter referred to as EVs), plug-in hybrid vehicles (hereinafter referred to as PHVs), and hybrid vehicles (hereinafter referred to as HVs). .) Appeared. These EVs, PHVs, and HVs are equipped with a motor for traveling. In EVs, the vehicle is driven by driving the motor. In PHVs and HVs, the engine is provided in addition to the motor, and the engine or the motor is driven. Running. In these automobiles, a battery including a lithium ion battery or the like is used to drive a motor for traveling.

In automobiles powered by a motor, the battery is discharged by driving the motor, and the battery is charged during deceleration, etc., or charged using an external power supply, and the battery is repeatedly charged and discharged. . In order to stably discharge the battery, it is necessary to keep the battery temperature within an appropriate range. For example, in the case of a lithium ion battery, the appropriate temperature region is said to be 0 to 40 ° C.

If the temperature of the battery deviates from the appropriate range, the efficiency of discharge decreases and the driving force of the motor also decreases, which affects driving. Therefore, when the battery temperature is low when using the battery, it is necessary to heat the battery. On the other hand, when the battery temperature becomes high, it is necessary to remove the heat and keep the battery temperature within an appropriate range. There is. By performing thermal management of the battery in this way, the discharge can be stabilized and the battery usage efficiency does not decrease. Therefore, the power consumption of the battery can be suppressed and a predetermined cruising distance can be maintained.
Moreover, since the battery and the battery case are not excessively burdened by performing thermal management of the battery, the deterioration of the battery and the battery case due to the thermal history can be prevented.
Note that a battery for driving an automobile includes one or a plurality of battery modules connected to a plurality of cells, that is, a storage battery, and a battery case for storing the storage battery.

In Patent Document 1, in order to suppress deterioration in battery performance at low temperatures, the heating unit is operated when the temperature measurement unit is lower than the lower limit temperature of the battery, and the uniformization process is performed to suppress temperature variation after heating. A temperature control device is disclosed in which an overdischarge state due to heating is prevented from being performed.

In Patent Document 2, a battery case having a plurality of stacked battery cells is provided with a coolant inlet into which a coolant is introduced and a coolant outlet from which the coolant is discharged, and the coolant is circulated to thereby provide a battery. A battery pack case for removing the heat is disclosed.

JP 2007-244050 A Special table 2010-521791

However, in the temperature control device disclosed in Patent Document 1, as a device for stabilizing discharge, a temperature measurement unit that measures the temperature of the battery, a voltage measurement unit that detects the open circuit voltage of the battery, and the temperature of the battery When the temperature is low, it is necessary to provide a control unit that operates the heating unit, further drives the fan to forcibly convection the air, and performs a process for equalizing the temperature, and controls the temperature control device and the like. It is necessary to provide a temperature control program, and the apparatus and method for keeping the battery temperature within an appropriate range when the battery is used have become complicated. Further, when the temperature of the battery and the gas surrounding the battery becomes too high, there is a problem that the temperature of the battery cannot be lowered even if the fan is driven.

The battery pack case disclosed in Patent Document 2 does not describe at all what the coolant is, and does not describe a sealing method or the like when circulating the liquid. It is thought that the air around the case is used as a coolant. In this case, similarly to Patent Document 1, when the temperature of the battery and the air around the battery is high, there is a problem that the temperature of the battery cannot be lowered even if air is circulated inside the battery pack case. there were.
Patent Document 2 focuses only on cooling when the temperature of the battery becomes high, and this battery pack case is not useful when the temperature of the battery becomes low.

The present invention has been made in view of such problems. When the temperature of the storage battery is likely to be lower than the appropriate range, the storage battery can be heated, and the temperature of the storage battery is higher than the appropriate range. In such a case, an object of the present invention is to provide a battery case that can prevent the temperature of the storage battery from rising and can maintain the temperature of the storage battery in an appropriate range, and a battery using the battery case. .

The battery case of the present invention is a battery case for storing a storage battery that supplies electric power to a vehicle driving motor, and the battery case is made of a resin containing a heat storage material.

Since the battery case of the present invention includes a heat storage material, if the temperature in the battery case is likely to be higher than the appropriate temperature due to heat generated from the storage battery when the vehicle drive motor is driven, the battery case The internal heat is taken away and removed, and the temperature of the storage battery can be kept at an appropriate temperature. At this time, the heat storage material is in a state of storing heat by taking heat away. Also, if the temperature inside the battery case is likely to be lower than the appropriate temperature when starting the vehicle drive motor or in winter, the inside of the battery case can be heated by dissipating heat from the heat storage material into the battery case. The temperature of the storage battery can be maintained at an appropriate temperature.
Thus, since the battery case of the present invention includes a heat storage material, it can play a role of both heat removal of the storage battery and heating of the storage battery, and the temperature of the storage battery in the battery case can be set appropriately. Can be kept in the temperature range.
In addition, by using such a battery case, it is not necessary to construct a facility or a system for heat removal of the storage battery and heating of the storage battery as in the past due to the action of the above-described heat storage material, or conventionally Can be made smaller. Therefore, it is possible to reduce the amount of power consumed by removing heat from the storage battery and heating the storage battery.

The content ratio of the heat storage material in the battery case of the present invention is preferably 25 to 70% by weight with respect to the weight of the battery case.
By setting the content ratio of the heat storage material in the battery case of the present invention to a range of 25 to 70% by weight with respect to the weight of the battery case, the temperature of the storage battery inside the battery case is reduced by heat storage or heat dissipation by the heat storage material described above. The effect of keeping in an appropriate temperature range is easily obtained.

When the content ratio of the heat storage material in the battery case is less than 25% by weight, the amount of the heat storage material is too small, so that it is difficult to obtain the effect of keeping the storage battery inside the battery case in an appropriate temperature range. On the other hand, when the content of the heat storage material in the battery case exceeds 70% by weight, since the proportion of the resin is small, molding becomes difficult, and it becomes difficult to produce a battery case that satisfies required characteristics such as strength.

In the battery case of the present invention, the heat storage material is preferably a hollow capsule in which a heat storage material is enclosed.
In the battery case of the present invention, when the heat storage material is enclosed in the hollow capsule, even if the heat storage material undergoes a phase transition, the heat storage material does not leak out of the hollow capsule. That is, the heat storage material can be prevented from leaking into the battery case. Therefore, the battery using the battery case can be repeatedly used for heat exchange.

In this specification, the “heat storage substance” means a substance that undergoes a phase transition at a temperature between a high temperature side temperature and a low temperature side temperature in heat exchange. Examples of the phase transition include a solid-to-liquid phase transition, a solid-to-gas phase transition, a liquid-to-solid phase transition, a liquid-to-gas phase transition, and a gas-to-solid phase transition. . In the battery case of the present invention, the phase change material is preferably a material that undergoes a phase transition from a solid to a liquid or from a liquid to a solid at a temperature between a high temperature side temperature and a low temperature side temperature in heat exchange. .

In the battery case of the present invention, it is desirable that the phase transition temperature of the heat storage material is 30 to 70 ° C.
In the battery case of the present invention, when the temperature in the battery case becomes lower than the phase transition temperature, the heat storage material undergoes a phase transition from a liquid to a solid, and heat is released during the phase transition, so that the storage battery in the battery case is added. It will be warmed.
On the other hand, when the temperature inside the battery becomes higher than the phase transition temperature, the heat storage material undergoes a phase transition from solid to liquid, and the storage battery in the battery case is deprived of heat from the gas or storage battery in the battery case during the phase transition. Heat will be removed.
In the battery case of the present invention, when the phase transition temperature of the heat storage material is set to 30 to 70 ° C., the storage battery can be appropriately heated and removed, and the temperature of the storage battery in the battery case is set appropriately. Can be kept within range.

The battery case of the present invention preferably has an inlet and an outlet for the heat exchange medium.
When the battery case of the present invention has an inlet and an outlet for the heat exchange medium, a heat exchange medium such as air or water can be circulated in the battery case to remove heat from the storage battery and heat from the heat storage material. As a result, heat can be removed from the heat storage material and the heat medium, and the temperature of the storage battery in the battery case can be more efficiently maintained within an appropriate range.

The battery of the present invention comprises the battery case of the present invention and a storage battery accommodated in the battery case.
In the battery of the present invention, the above-described battery case is used, and since this battery case contains a heat storage material, it can play a role of both heating and heat removal in the battery case, The temperature of the storage battery in the battery case can be maintained in an appropriate temperature range. As a result, the battery discharge stability does not decrease and the battery usage efficiency does not decrease, so that power consumption in the battery can be suppressed and a predetermined cruising distance can be maintained.
Moreover, since the battery and the battery case are not excessively burdened by performing thermal management of the battery, the deterioration of the battery and the battery case due to the thermal history can be prevented.

FIG. 1A is a perspective view schematically showing an example of the battery case of the present invention, and FIG. 1B is an exploded perspective view of the battery case shown in FIG. FIG. 2 is a perspective view schematically showing another example of the battery case of the present invention.

(Detailed description of the invention)
Hereinafter, the battery case of the present invention will be described in detail.
The battery case of the present invention is a battery case for storing a storage battery that supplies electric power to a vehicle driving motor, and the battery case is made of a resin containing a heat storage material.

FIG. 1A is a perspective view schematically showing an example of the battery case of the present invention, and FIG. 1B is an exploded perspective view of the battery case shown in FIG.
FIG. 1B also shows a storage battery housed in the battery case.
As shown in FIG. 1A, the battery case 10 has a substantially rectangular parallelepiped shape, and a slit 14 for allowing a cooling gas to pass therethrough is formed on the side surface. In addition, a through hole 12 a for inserting an external input and output terminal of the storage battery is formed on one end surface of the battery case 10.

Moreover, as shown in FIG.1 (b), the battery case 10 is assembled by accommodating the storage battery 100 and combining the 1st case 10a and the 2nd case 10b.
The external input terminal and the external output terminal 12 of the storage battery 100 are inserted through the through hole 12a.
In addition, as the storage battery 100, a battery module in which a plurality of chargeable and dischargeable battery cells are stacked can be used.

The first case 10a and the second case 10b constituting the battery case 10 are made of a resin containing a heat storage material, and the second case 10b is fixed to the first case 10a with a bolt or the like. Through-holes 13a and 13b are formed in the first case 10a and the second case 10b, respectively.

1 (a) and 1 (b) show an example of the battery case of the present invention. However, the battery case of the present invention is not limited to the above shape, and power is supplied to the vehicle drive motor. As long as it has a structure that can store the storage battery to be supplied, it may have any shape and structure.
However, in order for the battery case to fully exhibit the heat storage effect, it is desirable that the surface area inside the battery case is as large as possible, and it is desirable that the space other than the space occupied by the storage battery is as small as possible.
It is desirable that the thickness of the battery case is 5 to 15 mm in order to have excellent mechanical properties as a structural member and to fully exhibit the heat storage function.

It is desirable to use a thermoplastic resin as the resin constituting the battery case. This is because the thermoplastic resin has good compatibility with the heat storage material and has a degree of freedom during molding. As thermoplastic resins, AS resin, ABS resin, polyethylene resin, polyester resin (polyether ester elastomer, etc.), polypropylene resin, ethylene-propylene copolymer, polyvinylidene chloride, polyamide, acetal resin, polycarbonate resin, polyphenylene sulfide resin , Polyetherimide resin, aromatic polyetherketone resin, polysulfone resin, fluororesin (polyvinylidene fluoride, etc.), polyamideimide resin, acrylic resin and the like. Among these, it is desirable to use polypropylene resin, polyethylene resin, polyester resin, etc. in consideration of heat resistance.

As the heat storage material constituting the battery case, a hollow capsule in which a heat storage material is enclosed can be used. The heat storage material is preferably at least one selected from the group consisting of paraffin, sodium sulfate hydrate, sodium acetate hydrate, calcium chloride hydrate, erythritol, and sodium thiosulfate. Since these substances can easily control the melting point, they can be suitably used as heat storage substances. Furthermore, it is desirable to use paraffin as the heat storage material in terms of design freedom for use and use.

The phase transition temperature of the heat storage material is desirably 30 to 70 ° C. In addition, the type of the heat storage material is not limited, but in the phase transition of the heat storage material in the above temperature range, the change from liquid to solid or the change from solid to liquid is controlled because the volume change is small. Therefore, a heat storage material having such characteristics is preferably used.

When the temperature of the storage battery is likely to decrease when the battery is used by using the heat storage material having a temperature range of the phase transition temperature of 30 to 70 ° C. When the storage battery is heated, on the other hand, when the temperature of the storage battery is likely to rise, the storage battery can be removed by phase transition from solid to liquid and stored to keep the temperature of the storage battery within an appropriate range.
As the heat storage material, only those having the same phase transition temperature may be used, or a plurality of types of heat storage materials having different phase transition temperatures may be mixed, but in the case of the present invention, different phase transition temperatures are used. It is preferable to use two kinds of heat storage materials.

When two kinds of heat storage materials are used, if the temperature of the storage battery is likely to be too low, the storage battery A having a function of heating the storage battery and suppressing the temperature decrease of the storage battery, and the temperature of the storage battery are too high In such a case, it is desirable to combine the heat storage material B having a function of removing heat from the storage battery and suppressing an increase in the temperature of the storage battery.
In this case, the phase transition temperature of the heat storage material in the heat storage material A is preferably 30 to 40 ° C., and the phase transition temperature of the heat storage material in the heat storage material B is preferably 40 to 70 ° C. Since the heat storage material using the above-mentioned material such as paraffin as the heat storage material can easily adjust the melting point, the use of the above-mentioned heat storage material enables the above-mentioned two types of heat storage materials having different phase transition temperatures. It can manufacture easily and can control the temperature of a storage battery in an appropriate temperature range.

When two or more kinds of heat storage materials having different phase transition temperatures are used, these heat storage materials may be enclosed in the same hollow capsule, or may be enclosed in different hollow capsules for each heat storage material.

As a material of the hollow capsule constituting the heat storage material, an organic resin or an inorganic material can be used. Moreover, it is desirable to use a material that is durable to the phase transition temperature of the heat storage material as the material of the hollow capsule.
As the inorganic material for the hollow capsule, for example, ceramics such as silica, carbon, and alumina can be used. In addition, thermoplastic elastomers such as olefin thermoplastic elastomers can be used as the organic resin for the hollow capsule, but the following types of thermosetting resins are desirable. When the hollow capsule is a thermosetting resin, it is possible to prevent the hollow capsule from being destroyed by heat during heat exchange.
The thermosetting resin is preferably at least one thermosetting resin selected from the group consisting of melamine resin, urea resin, polyurethane, polyurea, polyamide and polyacrylamide.

The hollow capsule constituting the heat storage material may be filled with a filler having a thermal conductivity higher than that of the hollow capsule.
When a filler having such a high thermal conductivity is sealed in the hollow capsule, heat is easily transferred to the heat storage material. That is, the heat transfer rate to the heat storage material or the heat transfer rate from the heat storage material can be improved. Therefore, heat can be exchanged efficiently.
The filler content is desirably 10 to 30% by weight based on the weight of the entire hollow capsule. When the content of the filler is within the above range, the thermal conductivity can be improved without impairing the strength of the hollow capsule. In addition, the weight of the whole hollow capsule used as the base of filler content does not include the weight of the heat storage material to be included.

Examples of the filler include, but are not limited to, inorganic fillers composed of, for example, glass, silica, wollastonite, aluminum hydroxide, kaolin, titanium oxide, alumina, mica, talc, carbon, potassium titanate, and copper. A metal filler or the like composed of, for example, can be used. The filler may be in the form of particles, fibers, or whiskers.
Further, the metal filler may be one obtained by performing metal plating on the surface of an inorganic filler or resin particles. From the viewpoint of improving the thermal conductivity of the hollow capsule, glass fiber and carbon fiber are desirable.

Commercially available products such as trade name manufactured by Mitsubishi Paper Industries Co., Ltd .: Thermo Memory, microcapsules for thermal storage manufactured by Miki Riken Co., Ltd., trade name: Riken Resin, and trade name: CALGRIP manufactured by JSR Corporation. Can be used.

The average particle size of the heat storage material is preferably 10 to 500 μm, and more preferably 20 to 200 μm.
When the average particle diameter of the heat storage material is 10 μm or more, the amount of the heat storage material enclosed in the heat storage material becomes a sufficient amount, and the heat exchange efficiency with respect to the amount of the heat storage material becomes sufficiently high.
When the average particle diameter of the heat storage material is 500 μm or less, the surface area of the heat storage material is sufficiently large, and the heat transfer rate to or from the heat storage material is sufficiently high. As a result, the heat exchange efficiency is improved.

Further, the resin constituting the battery case may include a filler having a thermal conductivity higher than that of the resin.
When the resin contains a filler having such a thermal conductivity, the heat transfer rate between the resin and the heat storage material can be improved. Moreover, since the heat storage material contains the heat storage material, as a result, the speed of heat transfer to the heat storage material or the speed of heat transfer from the heat storage material can be improved. Therefore, heat can be exchanged efficiently.
The resin may contain a stabilizer, a redox agent, a molding aid, a decomposition inhibitor, a lubricant, a release agent, a colorant such as a pigment, a plasticizer, and the like.

The content ratio of the heat storage material in the battery case of the present invention is preferably 25 to 70% by weight and more preferably 30 to 70% by weight with respect to the weight of the battery case.
When the content ratio of the heat storage material is 25% by weight or more, the amount of the heat storage material becomes a sufficient amount, and the heat exchange efficiency in the battery case is improved. When the content ratio of the heat storage material is 70% by weight or less, the ratio of the resin is increased, and the strength of the battery case is sufficiently increased.

The battery case of the present invention preferably has an inlet and an outlet for the heat exchange medium.
When the battery case of the present invention has a heat exchange medium introduction port and a discharge port, a heat exchange medium such as air can be circulated in the battery case, and heat removal of the storage battery and heat storage material can be performed. As a result, heat can be removed from the heat storage material and the heat medium, and the temperature of the storage battery in the battery case can be more efficiently maintained within an appropriate range.

FIG. 2 is a perspective view schematically showing another example of the battery case of the present invention.
In FIG. 2, in order to show the storage battery accommodated in the battery case, the battery case is shown through.
The battery case 20 is a large-sized battery case, and as shown in FIG. 2, a plurality of storage battery modules 200 formed by combining a plurality of storage batteries 100 (two in this figure) are housed inside. Has been.
Further, the battery case 20 is provided with a heat exchange medium introduction port 21 and a heat exchange medium discharge port 22 of a gas such as air, and a heat exchange medium having a low temperature or a high temperature depending on the situation. A heat exchange medium can be introduced into the battery case 20.

The battery case 20 can be divided into a first case 20a and a second case 20b. The first case 20a and the second case 20b have a substantially rectangular parallelepiped shape in which one side is completely open, the first case 20a is slightly larger, and the second case 20b is placed in the first case 20a. The battery case 20 can be assembled by fitting.

Therefore, when storing the storage battery module 200, after dividing the battery case 20, the storage battery module 200 is stored, the second case 20b is fitted into the first case 20a, and the second case 20b and the second case 20b. The second case 20b may be fixed to the first case 20a by inserting a screw or the like through the through-holes 23 respectively formed in the first case 20a.

Although not shown in FIG. 2, the heat exchange medium inlet 21 is connected to a hose coupled with a blower such as a fan, and the blower supplies a low temperature gas or a high temperature gas to the battery case. For example, a heater or a radiator may be provided.
Regarding the inlet and outlet of the heat exchange medium, the number of inlets and outlets of the heat exchange medium may be one or plural. Moreover, the inlet and outlet of the heat exchange medium may be formed with slits as shown in FIG.
Furthermore, when the heat exchange medium is a liquid such as water, a passage for the heat exchange medium may be provided inside the battery case so as not to contact the storage battery.

In the battery provided with the battery case described above, when the temperature of the storage battery inside the battery case is too low, it can be heated by the heat storage material included in the battery case, and the decrease in the temperature of the storage battery can be suppressed. By introducing the heat exchange medium heated by a heater or the like into the battery case, it is possible to prevent the temperature of the storage battery from being excessively lowered.

On the other hand, when the temperature of the storage battery inside the battery case is too high, the heat can be removed by the heat storage material contained in the battery case, and the temperature of the storage battery can be prevented from rising too much, but it is further cooled by the outside air and radiator By introducing the heat exchange medium into the battery case, it is possible to prevent the temperature of the storage battery from rising excessively.

The battery case shown in FIG. 2 is made of a resin containing a heat storage material, similar to the battery case shown in FIG. 1 except that the shape is different. The type of the resin, the structure of the heat storage material (the material of the heat storage material, The characteristics, the capsule material, the characteristics, the ratio of the heat storage substance and the capsule, etc.) can be the same as those of the battery case shown in FIG. In addition, the battery case of the present invention is not limited to the battery case having the shape shown in FIGS. 1 and 2, and may have any shape as long as it is made of a resin containing a heat storage material. .

When manufacturing the battery case of the present invention described above, a hollow capsule encapsulating a heat storage material and a resin are mixed to produce a pellet, and the pellet is used to form a battery by a molding method such as injection molding or extrusion molding. What is necessary is just to produce a case. When the battery case includes a plurality of parts, the battery case can be manufactured by combining a plurality of parts after the plurality of parts are manufactured.

The battery of the present invention comprises the battery case of the present invention described above and a storage battery housed in the battery case.
In the battery of the present invention, the above-described battery case of the present invention is used. Since this battery case contains a heat storage material, it can play a role of both heating and heat removal in the battery case. The temperature of the storage battery in the battery case can be kept in an appropriate temperature range. As a result, the discharge stability of the battery does not decrease and the battery usage efficiency does not decrease, so that a predetermined cruising distance can be maintained.
Moreover, since the battery and the battery case are not excessively burdened by performing thermal management of the battery, the deterioration of the battery and the battery case due to the thermal history can be prevented.

Since the battery case has been described in detail in the above-described battery case of the present invention, the description thereof is omitted here.
The storage battery used in the battery of the present invention is not limited as long as it is a storage battery that supplies power to a vehicle drive motor, and may be a unit of a battery module including a plurality of battery cells. A storage battery module in which a plurality of storage batteries are combined may be used, or another storage battery may be used. The storage battery may be a lithium ion battery or other types of batteries.

Example 1
(Battery case and battery manufacturing process)
In the battery case used in Example 1, resin pellets made of a heat storage material and a thermoplastic resin were produced, and the resin pellets were molded by injection molding.
Below, the preparation method of the resin pellet was described.
(Material preparation process)
As a heat storage material, a capsule heat storage material (product name: PMCD-32, manufactured by Miki Riken Co., Ltd.) using paraffin having a phase transition temperature of 32 ° C. as a heat storage material was prepared. The heat storage material may be used after the moisture content of the heat storage material is adjusted by drying at a temperature higher than the phase transition temperature (drying condition: 50 to 80 ° C. for 1 to 5 hours). Drying was performed at 2 ° C. for 2 hours.
A polypropylene resin (Novatech PP MG05ES manufactured by Nippon Polypro Co., Ltd.) having a softening point of 135 to 150 ° C. was prepared as a base resin for the resin pellets. In addition, 15 kg of the heat storage material was weighed and prepared with respect to 10 kg of the base resin so that the mixing ratio of the resin pellets was base resin: heat storage material = 40: 60 by weight.
(Extruder injection process)
The polypropylene resin was put into a cylinder in the extruder, and the base resin was softened in the extruder by setting the cylinder temperature to 190 ° C. or higher (however, 160 ° C. or higher). At this time, the heat storage material was put into the side feeder.
(Base resin-heat storage material mixing, pellet making process)
While flowing the softened base resin into the extruder, the heat storage material was mixed into the base resin by introducing the heat storage material from the side feeder. The temperature of the heat storage material when the side feeder was charged was 37 ° C., and it was confirmed that the state of phase transition from the solid phase to the liquid phase was maintained.
The heat storage material-containing resin thus mixed was extruded from a die into a strand, and the strand was cut into pellets to produce resin pellets containing the heat storage material.
At this time, a cylindrical heat storage material-containing resin pellet having a height of 3 ± 0.3 mm and a diameter of 3 ± 0.3 mm was obtained.

Using the resin pellets, injection molding (press temperature: 180 ° C., press pressure: 10 kg / cm ² ) was performed to produce a first case 10a and a second case 10b shown in FIG.

Thereafter, a storage battery, which is a battery module in which a plurality of battery cells made of lithium ion batteries are stacked, is placed in the first case 10a, and the storage battery is accommodated in the battery case by combining the second case 10b. A battery was made.

(Motor drive test)
A thermocouple was inserted into the battery produced in Example 1 so that the temperature of the storage battery could be monitored. Thereafter, the battery produced in Example 1 was connected to a motor for driving the vehicle, the motor was driven for a long time, and the temperature of the storage battery inside the battery case was measured.

(Comparative Example 1)
A battery case having the same dimensions and shape as the battery case produced in Example 1 was produced in the same manner as in Example 1 using polypropylene resin pellets containing no heat storage material as resin pellets used in the production of the battery case.
Thereafter, the same storage battery as that used in Example 1 is placed in the part corresponding to the first case, and the battery in which the storage battery is stored in the battery case using the part corresponding to the second case. Produced.
Using the produced battery according to Comparative Example 1, a motor drive test was conducted in the same manner as in Example 1.

(Results of motor drive test)
As a result of the motor drive test described above, in the battery according to Comparative Example 1, the temperature of the storage battery continuously increased. However, in the battery using the battery case of the present invention according to Example 1, the phase of the heat storage material was In the temperature region exceeding the transition temperature of 32 ° C., the temperature of the storage battery tended to be constant over a predetermined time. That is, it has been found that a battery using the battery case of the present invention has a function of keeping the temperature of the storage battery within an appropriate temperature range.

(Example 2)
A battery case was prepared in the same manner as in Example 1 except that paraffin having a phase transition temperature of 9 ° C. was used as the heat storage material in the heat storage material, and a battery in which the storage battery was stored in the battery case was manufactured.

(Heat removal test)
A thermocouple was inserted into the batteries produced in Example 2 and Comparative Example 1 so that the temperature of the storage battery could be monitored. Next, the battery according to Example 2 and the battery according to Comparative Example 1 are placed in a temperature control device capable of lowering the temperature inside the device, and the temperature is gradually lowered from room temperature. The temperature was measured.

(Result of heat removal test)
As a result of the heat removal test described above, in the battery according to Comparative Example 1, the temperature of the storage battery continuously decreased. However, in the battery using the battery case of the present invention according to Example 2, the phase of the heat storage material In the temperature range below the transition temperature of 9 ° C., the temperature of the storage battery tended to be constant over a predetermined time. That is, it has been found that the battery using the battery case of the present invention has a function of keeping the temperature of the storage battery within the appropriate temperature range even in a low temperature region.

10, 20 Battery case 10a, 20a First case 10b, 20b Second case 12 External input terminal and external output terminals 12a, 13a, 13b, 23 Through hole 14 Slit 21 Heat exchange medium inlet 22 Heat exchange medium Discharge port 100 Storage battery 200 Storage battery module

Claims (6)

A battery case for storing a storage battery for supplying electric power to a vehicle drive motor,
The battery case is made of a resin containing a heat storage material. The battery case according to claim 1, wherein a content ratio of the heat storage material is 25 to 70% by weight with respect to a weight of the battery case. The battery case according to claim 1, wherein the heat storage material is a hollow capsule in which a heat storage material is enclosed. The battery case according to claim 3, wherein a phase transition temperature of the heat storage material is 30 to 70 ° C. 5. The battery case according to claim 1, further comprising a heat exchange medium introduction port and a discharge port. A battery comprising the battery case according to any one of claims 1 to 5 and a storage battery housed in the battery case.

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