JPH0576142B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a novel stacked redox temperature difference battery. More specifically, the present invention utilizes a redox reaction of redox pairs in an electrolyte solution as an electrode reaction, and a plurality of thin-layer redox temperature difference batteries are stacked thermally in parallel and electrically in series. A multilayer structure that can provide a practical terminal voltage, has features such as easy replacement of the electrolyte solution, no increase or decrease in internal pressure due to temperature changes, and the ability to suppress a drop in electromotive force. This invention relates to type redox temperature difference batteries.

Conventional technology Conventionally, when two electrodes of the same type are provided in an electrolyte solution containing ions that undergo a reversible charge transfer reaction with the electrodes and a temperature difference is applied between them, a potential difference between the two electrodes, that is, a thermal effect is created. It is known that electric power is generated, and such temperature difference batteries are useful as elements for thermoelectric conversion and temperature difference power generation.

The temperature difference batteries include those that utilize redox pairs such as metal elements in the electrode/metal ions in the electrolyte solution as electrode reactions occurring on the electrodes, and those that utilize redox pairs (M ^m+ , M ⁿ⁺ ) in the electrolyte solution. A so-called redox temperature difference battery that utilizes an oxidation-reduction reaction is known.

In these temperature difference batteries, the thermoelectromotive force is determined by the entropy change of the charge transfer reaction occurring on the electrodes and other factors.
Conventionally, methods for obtaining high thermoelectromotive force include, for example, changing the type of electrode or electrolyte, adjusting the hydrogen ion concentration, or complexing the electrolyte solution to form a complex with the ions contained therein. Methods such as adding agents are used.

However, even with this method, 1
The thermal electromotive force of a temperature difference battery is at most 1 mV/K.
In order to obtain a practical terminal voltage, it is necessary to stack a plurality of temperature difference batteries thermally in parallel and electrically in series.

By the way, in a temperature difference battery that uses the above-mentioned metal element/metal ion redox pair for the electrode reaction, only the metal ions are soluble in the electrolyte solution, so the metal is deposited on one electrode during the electrode reaction. If so, the metal must be transported to the other side through an external circulation circuit for continuous power generation. Therefore, when stacking such types of temperature difference batteries, it is necessary to electrically insulate the external circulation circuit for each temperature difference battery even if only the cell parts are stacked, but this is not possible due to technology. This is extremely difficult.

On the other hand, in a redox temperature difference battery that uses the redox reaction of a redox pair in an electrolyte solution as an electrode reaction, the active material is circulated by diffusion and convection inside the battery without any external power. Therefore, since an external circulation circuit like the above-mentioned type of battery is not required, stacking is easy.

When stacking such redox temperature difference batteries, if the electrolyte solution is completely confined, the electrolyte solution has a long lifespan, but it is difficult to replace it, and the internal pressure increases or decreases due to temperature changes in the electrolyte solution. This causes problems such as cell deformation. Therefore, it is important to make sure that the electrolyte solution is easy to replace and that the internal pressure does not increase or decrease due to temperature changes, and it is also important to take measures to prevent the electromotive force from decreasing as much as possible. It is.

Problems to be Solved by the Invention Under these circumstances, the present invention provides a structure in which the electrolyte solution can be easily replaced, the internal pressure does not increase or decrease due to temperature changes, and the electromotive force can be suppressed from decreasing. The purpose of this invention is to provide a stacked redox temperature difference battery that can provide a practical terminal voltage.

Means for Solving the Problems The present inventors have conducted intensive research to develop a stacked redox temperature difference battery that can provide a practical terminal voltage with the above characteristics. A plurality of layered redox temperature difference batteries are thermally arranged, and a temperature difference battery with a positive thermoelectromotive force and a temperature difference battery with a negative thermoelectromotive force are electrically connected in series on the same temperature side, Furthermore, the above objective can be achieved by connecting the electrolyte solutions of temperature difference batteries with positive thermoelectromotive force and the electrolyte solutions of temperature difference batteries with negative thermoelectromotive force, and providing a reservoir for each. Based on this finding, we have completed the present invention.

That is, the present invention thermally arranges a plurality of thin-layer redox temperature difference batteries in parallel using the redox reaction of redox pairs in an electrolyte solution as an electrode reaction, and connects a positive thermoelectromotive battery electrode and a negative thermoelectromotive battery electrode. The electrodes of the thermoelectromotive force batteries are electrically connected in series on the same temperature side, and the electrolyte solutions of the positive thermoelectromotive force batteries are connected to each other, and the electrolyte solutions of the negative thermoelectromotive force batteries are connected to each other. The present invention provides a stacked redox temperature difference battery characterized in that each of the cells is provided with a liquid reservoir.

The present invention will be explained in detail below.

The stacked redox temperature difference battery of the present invention has a plurality of thin layer redox temperature difference batteries stacked so that they are thermally in parallel and electrically in series. A temperature difference battery has a structure in which an electrolyte solution containing a redox pair is sandwiched between two inert electrode plates, and an electromotive force can be obtained by varying the temperature of the electrodes. At this time, an oxidation-reduction reaction of a redox pair in an electrolyte solution is used as an electrode reaction that produces an electromotive force.

In such a redox temperature difference battery,
Depending on the type of redox pair, a positive thermoelectromotive force or a negative thermoelectromotive force is generated. There are no particular restrictions on the type of this redox pair, and those commonly used in conventional redox temperature difference batteries can be used, but it is preferable to use one that provides as large an absolute value of the thermoelectromotive force as possible. In the case of a positive thermoelectromotive force battery, a redox pair of ferrous ions and ferric ions is preferable, and in the case of a negative thermoelectromotive force battery, a redox pair of ferric ion and ferrician ion is preferable. used.
In addition, in the electrolyte solution in the redox temperature difference battery, in order to further increase the absolute value of the electromotive force,
If desired, a complexing agent capable of forming a complex with ions in the solution, such as ethylenediaminetetraacetic acid disodium salt, ethylenediamine, triethylenediamine, etc., can be added.

Furthermore, there are no particular restrictions on the inert electrode plate used in the redox temperature difference battery.
Materials commonly used in conventional redox temperature difference batteries, such as carbon plates and platinum plates, can be used.

In such a redox temperature difference battery,
Since both redox couples of the active material are dissolved in solution, the circulation of the active material is carried out without any external power.
This is possible due to diffusion and convection inside the battery, so stacking is easy. For example, in a temperature difference battery that uses redox pairs such as metal elements in the electrode/metal ions in the electrolyte solution for electrode reactions, only the metal ions are soluble in the electrolyte solution, so one electrode The metal deposited on the cell must be transported to the other side through the external circulation circuit for continuous power generation. Therefore, in such temperature difference batteries, even if only the cell parts are stacked, the external circulation It is necessary to electrically insulate the circuit for each battery, which is technically extremely difficult, but the thin-layer redox temperature difference battery used in the present invention does not require such an external circulation circuit, so it is possible to is easy.

The feature of the stacked redox temperature difference battery of the present invention is that a plurality of such thin layer redox temperature difference batteries are thermally arranged in parallel, and the electrode of the positive thermoelectromotive force battery and the electrode of the negative thermoelectromotive force battery are arranged in parallel. The electrodes are electrically connected in series on the same temperature side, and in addition to making it easy to replace the electrolyte solution, the positive heat The electrolyte solutions of the electromotive force batteries and the electrolyte solutions of the negative thermoelectromotive force batteries are connected to each other, and each has a structure in which a reservoir is provided. By stacking thin-layer redox temperature difference batteries in this manner, a practical terminal voltage can be obtained.

Various embodiments of the stacked redox temperature difference battery of the present invention can be considered depending on the specifications of the arrangement of the positive thermoelectromotive force battery and the negative thermoelectromotive force battery.

Next, embodiments of the stacked redox temperature difference battery of the present invention will be described with reference to the accompanying drawings.

In Figure 1, positive thermoelectromotive force batteries and negative thermoelectromotive force batteries are arranged alternately, and the electrodes of the positive thermoelectromotive force battery and the electrode of the negative thermoelectromotive force battery are electrically connected at the same temperature side. Figure 1 a, b and c are cross-sectional views and temperature T ₁
They are a plan view seen from the side and a plan view seen from the temperature _T2 side. That is, as can be seen from FIG. 1, the electrolyte solution P of the positive thermoelectromotive force battery and the electrolyte solution N of the negative thermoelectromotive force battery are alternately housed through the partition wall 1, and The electrode plate 2 on the temperature T ₁ side in the thermoelectromotive force battery, the electrode plate 3 on the temperature T ₁ side in the positive thermoelectromotive force battery, and the electrode plate 2' on the temperature T ₂ side in the negative thermoelectromotive force battery and the positive The electrode plates 3' on the temperature T ₂ side of the thermoelectromotive battery have an integrated structure.

In the present invention, it is necessary to connect the Ps and the Ns and provide a liquid reservoir for each.
In such a structure, in order to connect P cells and N cells, a tube must be connected to each cell, making the structure complicated.

Figure 2 solves this problem by arranging positive thermoelectromotive force batteries and negative thermoelectromotive force batteries in parallel rows on a flat surface, and inserting holes in the cell partition walls of each battery. The electrolyte solution of the positive thermoelectromotive force battery and the electrolyte solution of the negative thermoelectromotive force battery are made common, respectively, and the electrodes of the positive thermoelectromotive force battery and the electrodes of the negative thermoelectromotive force battery are Figure 2 a, b and c
are a sectional view taken along line A-A', a plan view seen from the temperature T ₁ side, and a plan view seen from the temperature T ₂ side, respectively. That is, as can be seen from FIG. 2, the cells containing the electrolyte solution P of the positive thermoelectromotive force battery are arranged in a row through the partition wall 1 provided with the holes 4, and in parallel, the cells containing the electrolyte solution P are arranged in a row through the partition wall 1 provided with the holes 4. The cells containing the electrolyte solution N of the negative thermoelectromotive force battery are arranged in a row through a _partition wall provided with electrode plates 2' and 3' on the temperature _T2 side.
(symbols have the same meanings as above) are diagonally connected, and a common electrolyte solution P and N
each have a structure connected to a reservoir. In such a structure, the temperature T ₂
Since the electrode plates on the sides are connected diagonally, it is not possible to fabricate the electrode plate with a single square plate.

Fig. 3 solves this problem by arranging positive thermoelectromotive force batteries and negative thermoelectromotive force batteries in parallel on a plane in the order of positive, negative, positive and negative, and in the order of negative, positive and negative, respectively. A hole is made in the cell partition wall of each battery so as to connect the electrolyte solutions of the batteries having the same electromotive force in the diagonal direction, and the electrode of the positive thermoelectromotive battery and the electrode of the negative thermoelectromotive battery are connected. and,
It shows a structure in which one side is connected vertically and the other side is connected horizontally.
b, c and d are a-a' cross-sectional views, b-
b′ cross-sectional view, plan view from the temperature T ₁ side, and temperature T ₂
It is a plan view seen from the side. That is, as can be seen from FIG. 3, cells of the thermoelectromotive battery having the same reference numerals are arranged diagonally, and holes 4 are provided in the partition wall 1 of the cells so as to connect the electrolyte solutions of the diagonally oriented cells. and the electrode plates 2 and 3 (the symbols have the same meanings as above) on the temperature T ₁ side are vertically connected, and the electrode plates 2' and 3' (the symbols have the same meanings as above) on the temperature T ₂ side are arranged vertically. The electrolyte solutions P and N, which are horizontally connected and integrated, and which are further made common, have a structure in which they are each connected to a liquid reservoir.

In the stacked redox temperature difference battery having the above structure, holes are provided in the partition walls of the cells to connect the electrolyte solutions of the diagonally oriented cells. Two holes are provided above and below to prevent the electrolyte solution of the positive thermoelectromotive force battery and the electrolyte solution of the negative thermoelectromotive force battery from mixing.

The stacked redox temperature difference battery of the present invention is in the form of a tape with one or two rows as described above, but it can be folded back to form a sheet, and if flexible electrode plates are used, the whole can be made into a sheet. can be made into a flexible tape or sheet.

FIG. 4 shows that, taking advantage of these features, the stacked redox temperature difference battery of the present invention is placed around a heat pipe, with its longitudinal direction aligned with the axis of the pipe.
An example of a structure in which the electrode on the high temperature side is arranged so as to be in contact with the side surface of the pipe is shown, and a and b are a cross-sectional view and a side view, respectively. That is, the cells containing the electrolyte solution P of the positive thermoelectromotive force battery are arranged in a row through the partition wall 1 provided with holes 4, and in parallel thereto, the partition wall 1 provided with holes 4 is arranged. The cells containing the electrolyte solution N of the negative thermoelectromotive force battery are arranged in a row, and the low temperature side electrode plate 3' of the positive thermoelectromotive force battery and the low temperature side electrode plate 2 of the negative thermoelectromotive force battery ′ is a sheet-like laminated redox temperature difference battery having a structure in which they are connected diagonally, with their longitudinal direction aligned with the axis of the heat pipe 7, and the electrodes 2 and 3 on the high temperature side are connected to the side surface 6 of the heat pipe 7. They are arranged in a cylindrical shape so as to be in contact with each other with a target insulating film 5 interposed therebetween.

The tip of the heat pipe 7 where the battery is not placed is immersed in the high temperature liquid 9, and the electrodes 2' and 3' on the low temperature side are in contact with the coolant 8, and the electrolyte solutions P and N are each 10 and 11 are connected to the liquid reservoir. L indicates electrical load.

In this way, by combining a heat pipe and a stacked redox temperature difference battery, you can easily generate electricity by simply immersing the heat pipe in geothermal hot water, hot spring water, hot wastewater, etc., or by inserting it into a heat exhaust duct. is obtained. The low-temperature side electrode of the temperature difference battery can be cooled by simply exposing the electrode to the outside in the air, or by using a method such as attaching fins for air cooling, flowing a cooling liquid, or using a heat pipe. Good too.

Examples Next, the present invention will be explained in more detail with reference to Examples.

Example As shown in FIG. 4, a stacked redox temperature difference battery was placed in a heat pipe, and the battery was driven to examine its characteristics.

That is, platinum electrodes are used for both the high temperature side and the low temperature side, and the electrolyte solution of the positive thermoelectromotive force battery is an acidic hydrochloric acid solution containing 1M of ferrous chloride and 1M of ferric chloride. An aqueous solution containing 0.4M of potassium ferrocyanide and 0.4M of potassium ferrocyanide was used as the electrolyte solution of the thermoelectromotive cell. In addition, 13 positive thermoelectromotive force batteries and 13 negative thermoelectromotive force batteries were stacked in a Π shape. Furthermore, the heat pipe is a stainless steel tube (thermosyphon type, tube outer diameter 13 mm, heat medium R22).
was used, and 5°C cooling water was used as the cooling liquid.

FIG. 5 is a graph showing the relationship between the temperature of high temperature water and the electromotive force when the load is released.

The thermoelectromotive force of a single battery is the positive thermoelectromotive force of a battery.
0.6mV/K, negative thermoelectromotive battery -1.0mV/K
Therefore, in a laminated system, if there is no overall loss, the absolute value should be 22 mV/K, but when calculated from the temperature difference between the high temperature water and the cooling water, it is actually 12 mV/K. Ta. This is due to the large temperature drop between the electrode and the heat pipe, in addition to the loss caused by connecting the electrolyte solution.

Figure 6 shows the maximum output at the temperature of high-temperature water and the temperature difference when a voltage of 1/2 of the open electromotive force is applied as a load (this is the same as loading a resistance equal to the internal resistance). A graph shows the relationship between

FIG. 7 graphically shows the relationship between the temperature of high-temperature water and the amount of heat carried by the heat pipe.

Effects of the Invention The stacked redox temperature difference battery of the present invention has a structure in which a plurality of thin-layer redox temperature difference batteries are stacked thermally in parallel and electrically in series, using redox reactions of redox pairs in an electrolyte solution. In addition, the electrolyte solution can be easily replaced, and since the internal pressure does not increase or decrease due to temperature changes, the cell does not deform, and the electromotive force can be suppressed from decreasing.

The stacked redox temperature difference battery can provide a practical terminal voltage and is suitably used as an element for thermoelectric conversion or temperature difference power generation.

[Brief explanation of the drawing]

1, 2, and 3 respectively show different examples of the structure of the stacked redox temperature difference battery of the present invention, and FIGS. 1a, b, and c are sectional views, respectively, from the temperature _T1 side. The plan view as seen and the plan view as seen from the temperature T ₂ side, Figure 2 a, b and c are respectively A
−A′ cross-sectional view, temperature T ₁ side plan view, and temperature
Plan view from T ₂ side, Figure 3 a, b, c and d
are a-a' cross-sectional view, b-b' cross-sectional view, and temperature T ₁ respectively.
They are a plan view seen from the side and a plan view seen from the temperature _T2 side. Figures 4a and 4b are a cross-sectional view and a side view, respectively, of an example of a stacked redox temperature difference battery of the present invention arranged in a heat pipe. In the figure, 1 is the partition wall, 2 and 2' are the temperature T ₁ side (or high temperature side) of the negative thermoelectromotive force battery, respectively.
electrode plate and the electrode plate on the temperature T ₂ side (or low temperature side),
3 and 3' are the temperatures of the positive thermoelectromotive battery, respectively.
T ₁ side (or high temperature side) and temperature T ₂ side (or low temperature side)
7 is a heat pipe, 8 is a cooling liquid, 9 is a high temperature liquid, P and N are electrolyte solutions of positive and negative thermoelectromotive cells, respectively. Figures 5, 6 and 7 respectively show the temperature of high temperature water and the electromotive force when the load is released in one example of driving the stacked redox battery of the present invention placed in a heat pipe. , the relationship between the temperature of high-temperature water and the maximum output at that temperature when a voltage of 1/2 of the open electromotive force is applied as a load, and the relationship between the temperature of high-temperature water and the amount of heat carried by the heat pipe. It is a graph.

Claims (1)

[Claims] 1. A plurality of thin-layer redox temperature difference batteries that utilize redox reactions of redox pairs in an electrolyte solution are thermally arranged in parallel as electrode reactions, and electrodes of positive thermoelectromotive force batteries are used. Connect the negative thermoelectromotive force battery electrode in electrical series on the same temperature side,
Furthermore, the stacked redox temperature difference battery is characterized in that the electrolyte solutions of the positive thermoelectromotive force batteries and the electrolyte solutions of the negative thermoelectromotive force batteries are connected and each is provided with a reservoir. 2 Arrange positive thermoelectromotive force batteries and negative thermoelectromotive force batteries alternately so that the electrodes of the positive thermoelectromotive force batteries and the electrodes of the negative thermoelectromotive force batteries are electrically connected in series on the same temperature side. 2. The stacked redox temperature difference battery according to claim 1, wherein the stacked redox temperature difference battery is connected in a Π shape. 3. Line up the positive thermoelectromotive force batteries and the negative thermoelectromotive force batteries in parallel on a flat surface, make a hole in the cell partition wall of each battery, and insert the electrolyte of the positive thermoelectromotive force battery. The solution and the electrolyte solution of the negative thermoelectromotive force battery are common, and the electrode of the positive thermoelectromotive force battery and the electrode of the negative thermoelectromotive force battery are connected vertically on one side and on the other side. 2. The stacked redox temperature difference battery according to claim 1, wherein the stacked redox temperature difference battery is diagonally connected at the . 4. On a plane, positive thermoelectromotive force batteries and negative thermoelectromotive force batteries are arranged in parallel in a row in the order of positive, negative, positive and negative, and in the order of negative, positive and negative, respectively, and the batteries with electromotive forces of the same sign in the diagonal direction are A hole is made in the cell partition wall of each battery so that the electrolyte solution is connected, and the electrode of the positive thermoelectromotive force battery and the electrode of the negative thermoelectromotive force battery are connected vertically on either side. 2. A stacked redox temperature difference battery according to claim 1, which is connected laterally on the other side. 5. The stacked redox temperature difference battery according to any one of claims 1 to 4, wherein the redox pair in the positive thermoelectromotive force battery is a ferrous ion and a ferric ion. 6. The laminated redox temperature difference battery according to any one of claims 1 to 4, wherein the redox pair in the negative thermoelectromotive battery is a ferrician ion and a ferrician ion. 7. The heat pump according to claim 1, wherein the tube is arranged in a cylindrical shape around the heat pump so that the longitudinal direction is aligned with the axis of the pipe and the high temperature side electrode is in contact with the side surface of the pipe via an electrical insulating film. The laminated redox temperature difference battery according to any one of the above.