JP2013161598A - Battery device and battery heating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the energy efficiency as a whole in the case where a molten salt battery is used for a battery device used together with an internal combustion engine mounted on a vehicle and the like.SOLUTION: A battery device 100 used together with an internal combustion engine, like a battery device for driving a traveling electric motor in a hybrid vehicle, for example, has: a molten salt battery B using molten salt as an electrolyte and having a battery container; and a heat exchange part 30 inserted into a circulation passage of cooling water of the internal combustion engine 60, and that can perform heat exchange with the cooling water, to the molten salt battery B. The heat exchange part 30 can be configured by an inner wall part 21 and many fins 22 as a part of a container 20 for housing a battery pack of the molten salt battery B, for example.

Description

  The present invention relates to a battery device using a molten salt battery and a heating system thereof.

  The spread of hybrid vehicles using both an internal combustion engine and an electric motor is rapidly progressing. As a battery for driving an electric motor in a hybrid vehicle, a nickel metal hydride battery is mainly used. In recent years, a molten salt battery using a molten salt as an electrolytic solution has been developed and attracts attention (see Patent Document 1 and Non-Patent Document 1).

  The molten salt battery is made of a non-combustible material, and the operating temperature range is as wide as 57 ° C to 190 ° C. Therefore, there is no need for equipment such as exhaust heat space or fire prevention, and there is an advantage that even if individual unit cells are gathered at a high density to form an assembled battery, it is relatively compact as a whole. Therefore, such a molten salt assembled battery is expected as an in-vehicle battery for a hybrid vehicle in place of a nickel metal hydride battery.

JP 2009-67644 A

"SEI WORLD" March 2011 issue (VOL. 402), Sumitomo Electric Industries, Ltd.

However, a temperature of 57 ° C. or higher is necessary to melt the electrolyte of the molten salt battery, and 80 ° C. or higher is desirable for more stable operation. When electric power is supplied from another battery (for example, a lead storage battery) to the electric heater for obtaining such a temperature, the energy efficiency of the entire vehicle is reduced accordingly.
In view of this problem, an object of the present invention is to improve energy efficiency as a whole when a molten salt battery is used in a battery device used in combination with an on-vehicle or other internal combustion engine.

  (1) The present invention is a battery device used in combination with an internal combustion engine, wherein the molten salt is used as an electrolytic solution, and is inserted into one or a plurality of molten salt batteries including a battery container, and a cooling water circulation path of the internal combustion engine. The molten salt battery is provided with a heat exchanging portion capable of exchanging heat with the cooling water.

  In the battery device configured as described above, the cooling water becomes a high temperature (for example, 80 ° C. or more) by starting the internal combustion engine, and the molten salt battery is heated by heat exchange. Therefore, the molten salt battery can operate stably. In this way, since the molten salt battery can be operated using the exhaust heat of the internal combustion engine, energy required for heating when the molten salt battery is used in the battery device used in combination with the internal combustion engine. Saving energy and increasing energy efficiency as a whole.

(2) In the battery device of (1), the heat exchange unit may be formed as a part of a container that houses one or a plurality of battery containers.
In this case, since the container (outer container) that accommodates the battery container also serves as the heat exchange part, there is no structural waste, and heat can be efficiently conducted from the high-temperature water to the heat exchange part to heat the molten salt battery.

(3) Moreover, this invention is a battery heating system containing the battery apparatus of said (1) or (2), and the cooling device which water-cools an internal combustion engine, Comprising: A heat exchange part is a radiator in a cooling device, You may comprise the parallel path | route.
In this case, it is possible to easily provide an additional parallel path while suppressing the influence on the path in the existing cooling device.

(4) Moreover, this invention is a battery heating system containing the battery apparatus of said (1) or (2), and the cooling device which water-cools an internal combustion engine, Comprising: A heat exchange part is a radiator in a cooling device, and It may be provided in series and upstream of the radiator.
In this case, since the high-temperature water is dissipated in two stages of the heat exchange part and the radiator, the water temperature can be efficiently reduced.

  According to the battery device and the battery heating system of the present invention, when a molten salt battery is used in a battery device used in combination with an internal combustion engine, energy for necessary heating is saved and overall energy efficiency is increased. be able to.

1 is a schematic diagram showing in principle the basic structure of a power generation element in a molten salt battery. It is a perspective view which shows simply the lamination structure of a molten salt battery main body (main-body part as a battery). It is a cross-sectional view about the structure similar to FIG. It is a perspective view which shows the outline of the external appearance of the molten salt battery of the state accommodated in the battery container. (A) is sectional drawing which shows the state which arranged the molten salt battery in the container in multiple numbers, and was set as the battery apparatus, (b) is a figure equivalent to the bb sectional view in (a). It is an example of the connection diagram as an in-vehicle battery heating system. It is the figure which wrote the flow of water in the connection diagram of FIG. It is another example of the connection diagram as an in-vehicle battery heating system.

Hereinafter, a battery device including a molten salt battery according to an embodiment of the present invention will be described with reference to the drawings.
<Basic structure of molten salt battery>
First, the basic structure of the molten salt battery will be described.
FIG. 1 is a schematic diagram showing in principle the basic structure of a power generation element in a molten salt battery. In the figure, the power generation element includes a positive electrode 1, a negative electrode 2, and a separator 3 interposed therebetween. The positive electrode 1 is composed of a positive electrode current collector 1a and a positive electrode material 1b. The negative electrode 2 includes a negative electrode current collector 2a and a negative electrode material 2b.

The material of the positive electrode current collector 1a is, for example, an aluminum nonwoven fabric (wire diameter: 100 μm, porosity: 80%). The positive electrode material 1b is a mixture of, for example, NaCrO ₂ as a positive electrode active material, acetylene black, PVDF (polyvinylidene fluoride), and N-methyl-2-pyrrolidone at a mass ratio of 85: 10: 5: 100. It is a thing. And what was kneaded in this way is filled in the positive electrode collector 1a of an aluminum nonwoven fabric, and after drying, it presses at 100 Mpa, and it forms so that the thickness of the positive electrode 1 may be set to about 1 mm.
On the other hand, in the negative electrode 2, for example, a tin layer as a negative electrode active material is formed on the negative electrode current collector 2a made of aluminum by plating.

  The separator 3 interposed between the positive electrode 1 and the negative electrode 2 is obtained by impregnating a glass non-woven fabric (thickness 200 μm) or a polyolefin sheet (thickness 50 μm) with a molten salt as an electrolyte. This molten salt is, for example, a mixture of 56 mol% NaFSA (sodium bisfluorosulfonylamide) and 44 mol% KFSA (potassium bisfluorosulfonylamide), and has a melting point of 57 ° C. At a temperature equal to or higher than the melting point, the molten salt melts and becomes an electrolytic solution in which high-concentration ions are dissolved, and touches the positive electrode 1 and the negative electrode 2. Moreover, this molten salt is nonflammable. The operating temperature range of this molten salt battery is 57 ° C. to 190 ° C., but as described above, 80 ° C. or higher is desirable.

In addition, although the material, component, and numerical value of each part mentioned above are suitable examples, it is not limited to these.
For example, as the molten salt, in addition to the above, a mixture of NaFSA and LiFSA, KFSA, and CsFSA is also suitable. In addition, other salts may be mixed (organic cation, etc.). Generally, the molten salt includes (a) a mixture containing NaFSA, (b) a mixture containing NaTFSA (sodium bistrifluoromethylsulfonylamide), (c ) A mixture comprising NaFTA (sodium fluorosulfonyl-trifluoromethylsulfonylamide) is suitable. In these cases, since the molten salt of each mixture has a relatively low melting point, the molten salt battery can be operated with a small amount of heating.

Next, a more specific configuration of the power generation element of the molten salt battery will be described. FIG. 2 is a perspective view schematically showing a laminated structure of a molten salt battery main body (main body portion as a battery) 10, and FIG. 3 is a cross-sectional view of the same structure.
2 and 3, a plurality (six are shown) of rectangular flat plate-like negative electrodes 2 and a plurality (five are shown) of rectangles accommodated in a bag-like separator 3 respectively. The flat positive electrodes 1 are opposed to each other and are stacked in the vertical direction in FIG. 3, that is, in the stacking direction, to form a stacked structure.

  The separator 3 is interposed between the positive electrode 1 and the negative electrode 2 adjacent to each other. In other words, the positive electrode 1 and the negative electrode 2 are alternately stacked via the separator 3. For example, 20 positive electrodes 1 and 21 negative electrodes 2 and 20 separators 3 as “bags”, but 40 intervening between positive electrodes 1 and 2 are actually stacked. is there. The separator 3 is not limited to a bag shape, and may be 40 separated.

  In FIG. 3, the separator 3 and the negative electrode 2 are drawn so as to be separated from each other, but they are in close contact with each other when the molten salt battery is completed. Naturally, the positive electrode 1 is also in close contact with the separator 3. In addition, the vertical and horizontal dimensions of the positive electrode 1 are smaller than the vertical and horizontal dimensions of the negative electrode 2 in order to prevent the generation of dendrites, and the outer edge of the positive electrode 1 passes through the separator 3. Thus, it faces the peripheral edge of the negative electrode 2.

The molten salt battery main body 10 configured as described above is accommodated in a rectangular parallelepiped battery container made of, for example, an aluminum alloy, and forms a unit cell, that is, a physical individual as a battery.
FIG. 4 is a perspective view showing an outline of the appearance of the molten salt battery B in a state of being accommodated in such a battery container 11. 2 and 3, terminals 1p and 1n are drawn out of the battery case 11 from the positive electrode 1 and the negative electrode 2, respectively, while being insulated from the battery case 11. Further, a safety valve 12 for releasing the pressure when the internal atmospheric pressure rises excessively is provided at the upper part of the battery container 11. In addition, the inner surface of the battery container 11 is subjected to insulation treatment, and the battery container 11 is electrically insulated from the internal electrolyte.

  The molten salt battery B as described above is usually used in a state in which a plurality of batteries are gathered together and connected in series or in series and parallel to form a battery pack in order to obtain necessary voltage and current capacity according to the application. . However, basically, it is possible to use one unit.

<Battery device>
FIG. 5A is a cross-sectional view showing a battery device 100 in which a plurality of molten salt batteries B are arranged in a container (outer container) 20 (the number shown is just an example) to form an assembled battery. This battery device 100 is used in combination with an internal combustion engine having a water-cooled cooling device.
In the figure, a plurality of molten salt batteries B shown in FIG. 4 are arranged in a container 20 with a lid. Note that “with a lid” is an example of a form in consideration of a heat retaining effect, but “without a lid” may be used. Further, even in the case with a lid, it is not hermetically sealed but a gas vent hole is provided in the lid, but details are omitted here.

  (B) of FIG. 5 is a figure equivalent to the bb line cross section in (a). The container 20 includes a heat exchanging unit 30 having a jacket structure. A large number of heat exchanging portions 30 are formed over the four outer surfaces of the inner wall portion 21 in the water passage space (the space through which water passes) partitioned by the inner wall portion 21 of the container 20 and the inner wall portion 21 and the outer wall portion 23. And fins 22. The inner wall portion 21 and the fins 22 that are in contact with the molten salt battery B are made of metal having excellent thermal conductivity such as copper or aluminum. The other part of the container 20 is made of, for example, an aluminum alloy.

  There is a gap between the outer wall portion 23 of the container 20, the inner wall portion 21 and the fins 22, and water can be circulated. A pipe-shaped water supply port 24 is formed at one location of the outer wall 23, and a pipe-shaped drainage port 25 is formed at the other location. When water (high-temperature water) is introduced from the water supply port 24, heat exchange is performed between the water and the inner wall portion 21 and the fins 22. The heat received by the inner wall portion 21 and the fins 22 is conducted to the molten salt battery B. The water after the heat exchange is drained from the drain port 25. The positions of the water supply port 24 and the drain port 25 are only examples.

  When the battery device 100 configured in this manner is used as a power source in combination with the internal combustion engine 60 that is a power source, the cooling water of the cooling device 50 attached to the internal combustion engine 60 can be used as a heat medium. That is, as shown in FIG. 5B, the battery device 100 is disposed in the cooling water circulation path in the cooling device 50. In the battery device 100 arranged in this way, the cooling water becomes a high temperature (for example, 80 ° C. or more) by starting the internal combustion engine 60, and the molten salt battery B is heated by the heat exchange with the cooling water by the heat exchange unit 30. The Therefore, the molten salt battery B can operate stably.

In this way, by operating the molten salt battery B using the exhaust heat of the internal combustion engine 60, energy for heating the molten salt battery B can be saved, and the energy efficiency as a whole can be improved.
Moreover, since the heat exchange part 30 is formed as a part of the container 20, in other words, the container 20 also serves as the heat exchange part 30. Thereby, there is no waste in structure, and the molten salt battery B can be heated by efficiently conducting heat from the high-temperature water to the heat exchanging unit 30.

《Configuration of water channel for in-vehicle battery device》
Next, a configuration example of a cooling water channel when an example of an internal combustion engine is an automobile engine will be described. The automobile is a hybrid car, and the battery device is mainly used for driving a motor for traveling.

  FIG. 6 shows a state in which the container 20 including the heat exchanging unit 30 in the battery device 100 configured as described above is inserted into the circulation path of the engine cooling water as an example of the in-vehicle battery heating system S. FIG. In the figure, the hybrid vehicle has a cooling device 50 for water-cooling the engine in order to mount the engine (not shown) in the same manner as a conventional vehicle having only a fuel engine. The cooling device 50 includes a cooling water jacket 51 formed integrally with the engine, a water pump 52 for circulating water, a thermostat 53 having a valve function for opening and closing the water temperature, and air-cooling heat exchange. And a radiator 54 which is a vessel, and these constitute a water circulation path. Moreover, the container 20 (heat exchange part 30) is connected to the radiator 54 in parallel.

  In a vehicle having an engine cooling water circulation path as described above, the temperature of the water remains for a while after the engine is started using a battery (not shown) for engine startup (depending on the temperature). Is low. In this state, the thermostat 53 does not open, and water circulates between the water pump 52 and the water jacket 51 as indicated by the hatched lines in FIG.

  When the water temperature rises to a predetermined value and the thermostat 53 opens, the high-temperature water flows from the thermostat 53 into the radiator 54 and also into the container 20 of the battery device 100 as shown in FIG. Accordingly, each molten salt battery B is heated by the heat absorption by the heat exchanging unit 30 and easily exceeds the melting point and reaches 80 ° C. or higher. Thereby, each molten salt battery B will be in the state which can be operated stably, and it becomes possible to supply electric power from the battery apparatus 100 to the electric motor of a vehicle.

In this way, since the molten salt battery B can be operated using the exhaust heat of the engine, energy required for heating when the molten salt battery B is used as a vehicle battery is saved. The energy efficiency of the entire vehicle can be increased.
Further, as shown in FIG. 6, since the heat exchanging unit 30 forms a path parallel to the radiator 54 provided in the circulation path, it is added while suppressing the influence on the existing engine cooling path. It is possible to easily provide a general parallel path.

FIG. 8 is another example of a connection diagram of the battery heating system S.
The difference from FIG. 6 is that the container 20 is provided not in parallel with the radiator 54 but in series and upstream from the radiator 54. Others are the same as FIG.

In FIG. 8, when the water temperature rises to a predetermined value and the thermostat 53 opens, the high-temperature water first flows from the thermostat 53 into the container 20, and each molten salt battery B is heated by the endothermic heat of the heat exchange unit 30, and the melting point Easily reach 80 ° C or higher. Thereby, each molten salt battery B will be in the state which can be operated stably, and it becomes possible to supply electric power from the battery apparatus 100 to the electric motor of a vehicle. Further, the temperature of the water that has passed through the heat exchanging unit 30 is lowered, and further, heat is radiated by flowing into the radiator 54.
That is, in this case, since the high-temperature water is dissipated in two stages of the heat exchanging unit 30 and the radiator 54, the water temperature can be efficiently reduced.

<Others>
In addition, the structure of the container 20 and the heat exchange part 30 in the said embodiment is only an example, and various deformation | transformation are possible. For example, a flexible copper pipe is tightly wound around a battery pack in which a plurality of molten salt batteries B are arranged in close contact with each other and wound around the pipe multiple times. You may make it heat. In this case, a jacket formed by winding a pipe serves as a heat exchange unit. Further, a flat panel heater provided so as to meander a copper pipe through which high-temperature cooling water passes may be pressed against the assembled battery from the side surface or the bottom surface. In this case, the panel heater serves as a heat exchange unit.

  Moreover, in the said embodiment, the structure which heats the container of an assembled battery was shown. This is suitable for efficiently heating the entire assembled battery. However, basically, the molten salt battery B can be heated in units of one unit, and the entire assembled battery can be divided into small blocks and heated for each block.

  The battery device 100 shown in FIG. 5 is typically applied to a hybrid vehicle, but in addition to various vehicles (including railway vehicles and industrial vehicles) having a fuel engine and a water-cooled cooling device. Is also applicable. Further, when the battery device 100 is used in combination with various internal combustion engines including a ship, an aircraft, a power generation device, a stationary power engine, a heat engine, and the like, not only the vehicle, the cooling water of the internal combustion engine is used. Thus, heating necessary for the molten salt battery can be performed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 11 Battery container 20 Container 30 Heat exchange part 50 Cooling device 54 Radiator 60 Internal combustion engine 100 Battery apparatus B Molten salt battery S Battery heating system

Claims (4)

A battery device used in combination with an internal combustion engine,
One or a plurality of molten salt batteries including a molten salt as an electrolyte and a battery container;
A battery device comprising: a heat exchanging part inserted into a cooling water circulation path of the internal combustion engine and capable of exchanging heat with the cooling water with respect to the molten salt battery.   The battery device according to claim 1, wherein the heat exchange unit is formed as a part of a container that houses one or a plurality of the battery containers. A battery heating system including the battery device according to claim 1 and a cooling device for water-cooling the internal combustion engine,
The said heat exchange part is a battery heating system which comprises the path | route parallel to the radiator in the said cooling device. A battery heating system including the battery device according to claim 1 and a cooling device for water-cooling the internal combustion engine,
The said heat exchange part is a battery heating system provided in series with the radiator in the said cooling device, and upstream of the said radiator.

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