KR20200090504A - Secondary battery using carbon dioxide and complex electric power generation system having the same - Google Patents

Abstract

According to the present invention, a secondary battery capable of being charged and discharged includes: a cathode part including a first electrolyte which is a water electrolyte stored in a first reaction space and a cathode soaked at least partially in the first electrolyte; and an anode part including a second electrolyte which is a water-based electrolyte stored in a second reaction space and an anode soaked at least partially in the second electrolyte. During a discharge procedure, the temperatures of the first and second electrolytes are maintained at 60°C-80°C, carbon dioxide gas flows into the first electrolyte, a hydrogen ion and a bicarbonate ion are generated by a reaction between the carbon dioxide gas and the water of the first electrolyte, and the hydrogen ion and electrons of the cathode are combined to generate hydrogen gas.

Description

Secondary battery for producing hydrogen using carbon dioxide and a combined power generation system having the same {SECONDARY BATTERY USING CARBON DIOXIDE AND COMPLEX ELECTRIC POWER GENERATION SYSTEM HAVING THE SAME}

The present invention relates to a secondary battery, and more particularly, to provide a secondary battery using carbon dioxide and a composite power generation system having the same.

With the recent industrialization, greenhouse gas emissions are continuously increasing, and carbon dioxide accounts for the largest share of greenhouse gases. Carbon dioxide emissions by industry type are highest in energy sources such as power plants, and carbon dioxide generated in the cement/steel/refining industry including power generation accounts for half of the world's emissions. The CO2 conversion/utilization field can be largely divided into chemical conversion, biological conversion, and direct utilization, and the technical categories can be categorized into catalyst, electrochemistry, bioprocess, light utilization, inorganic (carbonation), and polymer. Carbon dioxide is generated in various industries and processes, and various approaches for carbon dioxide reduction are needed because carbon dioxide reduction cannot be achieved with one technology.

Currently, the US Department of Energy's Department of Energy (DOE) is a technology to reduce carbon dioxide, and is interested in CCUS technology, which is a combination of CCS (Carbon Capture & Storage) and CCU (CC & Utilization), and is promoting multilateral technology development. CCUS technology is recognized as an effective method to reduce GHG emissions, but faces the problems of high investment cost, the possibility of releasing harmful capture agents to the atmosphere, and low maturity. In addition, from an energy and climate policy perspective, CCUS provides a means to substantially reduce greenhouse gas emissions, but there are many complements to the realization of technology. Accordingly, there is a need to develop a breakthrough technology for a new concept of capturing, storing, and utilizing carbon dioxide more efficiently.

As a prior patent document related to the technical field of the present invention, Korean Patent Laid-Open No. 10-2015-0091834 includes a liquid cathode portion including a sodium impregnated solution and a cathode impregnated in a sodium-containing solution; An anode portion including a liquid organic electrolyte, an anode impregnated with the liquid organic electrolyte, and a negative electrode active material positioned on the anode surface; And a solid electrolyte located between the cathode part and the cathode part. And a hydrogen discharge part connected to the cathode part to draw hydrogen generated in the cathode part to the outside during discharge.

Republic of Korea Patent Publication No. 10-2015-0091834 "CO2 capture secondary battery" (2015.08.12.)

An object of the present invention is to provide a secondary battery for producing hydrogen together during discharge by using greenhouse gas carbon dioxide as a raw material.

Another object of the present invention is to provide a secondary battery with improved discharge capacity while producing hydrogen upon discharge with the removal of carbon dioxide.

In order to achieve the above object of the present invention, according to an aspect of the present invention, in a secondary battery capable of charging and discharging, at least the first electrolyte and the first electrolyte, which is an aqueous electrolyte accommodated in the first reaction space, A cathode part having a cathode that is partially locked; And an anode portion including a second electrolyte, which is an aqueous electrolyte accommodated in the second reaction space, and an anode that is at least partially submerged in the second electrolyte, and in the discharge process, the temperature of the first electrolyte and the second electrolyte is It is maintained at 60°C to 80°C, carbon dioxide gas is introduced into the first electrolyte, and hydrogen ions and bicarbonate ions are generated by the reaction of water and the carbon dioxide gas in the first electrolyte, and the hydrogen ions and the cathode A secondary battery in which hydrogen gas is generated by combining electrons is provided.

In order to achieve the above object of the present invention, according to another aspect of the present invention, in a secondary battery capable of charging and discharging, at least the first electrolyte, which is an aqueous electrolyte accommodated in the first reaction space, and the first electrolyte A cathode part having a cathode that is partially locked; A carbon dioxide treatment unit having the first electrolyte solution accommodated in an accommodation space communicating with the first reaction space; And an anode portion including a second electrolyte, which is an aqueous electrolyte accommodated in the second reaction space, and an anode that is at least partially submerged in the second electrolyte, and in the discharge process, the temperature of the first electrolyte and the second electrolyte is It is maintained at 60°C to 80°C, carbon dioxide gas is introduced into the first electrolyte solution in the accommodation space, hydrogen ions and bicarbonate ions are generated by reaction of water and the carbon dioxide gas in the first electrolyte solution, and the cathode part In the hydrogen ions and electrons of the cathode are combined to generate hydrogen gas, and the carbon dioxide processing unit separates the non-ionized carbon dioxide gas from the first electrolyte from the carbon dioxide gas flowing into the first electrolyte in the accommodation space. A secondary battery is provided that is not supplied to the cathode portion.

In order to achieve the above object of the present invention, according to another aspect of the present invention, a secondary battery capable of charging and discharging, comprising: an electrolyte that is an aqueous electrolyte accommodated in a reaction space; A cathode immersed in at least a portion of the electrolyte solution; And an anode at least partially submerged in the electrolytic solution, and in the discharge process, the temperature of the electrolytic solution is maintained at 60°C to 80°C, carbon dioxide gas flows into the electrolyte solution, and the reaction of water and the carbon dioxide gas in the electrolyte solution Thereby, a hydrogen ion and bicarbonate ion are generated, and a secondary battery in which hydrogen gas is generated by combining electrons of the hydrogen ion and the cathode is provided.

In order to achieve the above object of the present invention, according to another aspect of the present invention, in a secondary battery capable of charging and discharging, the aqueous electrolyte contained in the reaction space and the receiving space communicating with the reaction space is an electrolyte; A cathode in which at least a part is immersed in the electrolyte solution in the reaction space; And an anode in which at least a part is immersed in the electrolyte in the reaction space, and in the discharge process, the temperature of the electrolyte is maintained at 60°C to 80°C, and carbon dioxide gas is introduced into the electrolyte solution in the receiving space so that the Hydrogen ions and bicarbonate ions are generated by the reaction of water and the carbon dioxide gas, and hydrogen gas is generated by combining the electrons of the hydrogen ions and the cathode in the reaction space, and carbon dioxide flowing into the aqueous electrolyte in the accommodation space A secondary battery is provided in which the non-ionized carbon dioxide gas in the gas is separated from the electrolyte in the receiving space and is not supplied to the reaction space.

In order to achieve the above object of the present invention, according to another aspect of the present invention, the secondary battery for generating hydrogen by using carbon dioxide as a fuel in the discharge process; A reformer that produces hydrogen-rich reformed gas from hydrogen-containing fuel and generates carbon dioxide as a by-product; A fuel cell receiving reformed gas produced from the reformer as fuel; And a carbon dioxide supply unit supplying carbon dioxide generated in the reformer to the secondary battery.

In order to achieve the above object of the present invention, according to another aspect of the present invention, the secondary battery for generating hydrogen by using carbon dioxide as a fuel in the discharge process; A reformer producing a reforming gas rich in hydrogen from a hydrogen-containing furnace; A fuel cell receiving reformed gas produced from the reformer as fuel; And a hydrogen supply unit that additionally supplies hydrogen generated in the secondary battery as fuel of the fuel cell.

In order to achieve the above object of the present invention, according to another aspect of the present invention, the secondary battery for generating hydrogen by using carbon dioxide as a fuel in the discharge process; A reformer that produces hydrogen-rich reformed gas from hydrogen-containing fuel and generates carbon dioxide as a by-product; A fuel cell receiving reformed gas produced from the reformer as fuel; A carbon dioxide supply unit supplying carbon dioxide generated in the reformer to the secondary battery; And a hydrogen supply unit that additionally supplies hydrogen generated in the secondary battery as fuel of the fuel cell.

According to the present invention, all the objects of the present invention described above can be achieved. Specifically, it includes a cathode and a metal anode immersed in the electrolyte, which is an aqueous electrolyte, and the temperature of the electrolyte in the secondary battery generating hydrogen gas by introducing carbon dioxide gas into the electrolyte during the discharge process has a maximum current density of about twice the room temperature. By maintaining the optimum temperature of 60°C to 80°C, the performance of the secondary battery and the combined power generation system including the secondary battery is greatly improved.

1 is a schematic diagram showing a discharge state of a secondary battery for producing hydrogen using carbon dioxide according to a first embodiment of the present invention.
2 is a graph showing the results of a half-cell experiment according to the temperature of the electrolyte for the secondary battery of the embodiment shown in FIG.
3 is a graph showing HER initiation regions by temperature in the graph of FIG. 2.
4 is a graph showing HER voltage for each temperature at a current density of 10 mA/cm 2 in the graph of FIG. 2.
5 is a graph showing the results of a single cell experiment according to the temperature of the electrolyte for the secondary battery of the embodiment shown in FIG.
6 is a schematic diagram showing a discharge state of a secondary battery for producing hydrogen using carbon dioxide according to a second embodiment of the present invention.
7 is a schematic diagram showing a discharge state of a secondary battery for producing hydrogen using carbon dioxide according to a third embodiment of the present invention.
8 is a schematic diagram showing a discharge state of a secondary battery for producing hydrogen using carbon dioxide according to a fourth embodiment of the present invention.
9 is a schematic diagram showing a discharge state of a secondary battery for producing hydrogen using carbon dioxide according to a fifth embodiment of the present invention.
10 is a schematic diagram showing a discharge state of a secondary battery for producing hydrogen using carbon dioxide according to a sixth embodiment of the present invention.
11 is a schematic diagram showing a discharge state of a secondary battery for producing hydrogen using carbon dioxide according to a seventh embodiment of the present invention.
12 is a schematic diagram showing a discharge state of a secondary battery for producing hydrogen using carbon dioxide according to an eighth embodiment of the present invention.
13 is a view showing a schematic configuration of a complex power generation system having a secondary battery for producing hydrogen using carbon dioxide according to an embodiment of the present invention.

Hereinafter, the configuration and operation of the embodiment of the present invention will be described in detail with reference to the drawings.

1 shows a configuration of a secondary battery for producing hydrogen using carbon dioxide according to the first embodiment of the present invention. Referring to FIG. 1, the secondary battery 100 includes a cathode unit 110, an anode unit 150, and a connection unit 190 connecting the cathode unit 110 and the anode unit 150. The secondary battery 100 uses the carbon dioxide gas (CO ₂ ), which is a greenhouse gas, as a raw material during the discharge process to produce hydrogen (H ₂ ), which is an eco-friendly fuel.

The cathode unit 110 includes a first reaction vessel 110a that provides a first reaction space 111 therein, a first electrolyte 115 that is an aqueous electrolyte contained in the first reaction space 111, and a first A cathode 118 in which at least a part is immersed in the electrolyte 115 is provided. As the first electrolyte solution 115, an alkaline aqueous solution (in this embodiment, an elution of CO ₂ in a strong basic solution of 1M KOH is used), seawater, tap water, distilled water, and the like can be used. In this embodiment, the temperature of the first electrolyte 115 is preferably 60°C to 70°C, and most preferably 70°C. The cathode 118 is an electrode for forming an electrical circuit, and may be carbon paper, carbon fiber, carbon felt, carbon cloth, metal foam, metal thin film, or a combination thereof, and a platinum catalyst may also be used. In the case of the catalyst, in addition to the platinum catalyst, all other catalysts that can be generally used as a hydrogen generation reaction (HER) catalyst, such as a carbon-based catalyst, a carbon-metal-based composite catalyst, and a perovskite oxide catalyst, are included. A first inlet port 112, a first outlet port 113, and a first connector port 114 communicating with the first reaction space 111 are formed in the first reaction container 110a. The first inlet 112 is positioned below the first reaction space 111 so that it is located below the water surface of the first electrolyte 115. The first outlet 113 is positioned above the first reaction space 111 so as to be positioned above the water surface of the first electrolyte 115. Carbon dioxide, which is used as a raw material in the discharge process, is introduced into the first reaction space 111 through the first inlet 112, and the first electrolyte 115 may also be introduced, if necessary. The gas generated in the charging and discharging process is discharged to the outside through the first outlet 113. Although not shown, the first inlet 112 and the first outlet 113 may be selectively opened and closed in a timely manner by a valve or the like during charging and discharging. The first connector 114 is positioned below the water surface of the first electrolyte 115, and the connection part 190 is connected to the first connector 114. In the cathode unit 110, a carbon dioxide elution reaction occurs during a discharge process.

The anode unit 150 includes a second reaction vessel 150a providing a second reaction space 151 therein, a second electrolyte 155 serving as an aqueous electrolyte contained in the second reaction space 151, and a second An anode 158 in which at least a part is immersed in the electrolyte 155 is provided. As the second electrolyte solution 155, an alkali solution having a high concentration is used, for example, 1M KOH or 6M KOH may be used. In this embodiment, the temperature of the second electrolyte 155 is preferably 60°C to 80°C, and most preferably 70°C. The anode 158 is an electrode of a metal material constituting an electrical circuit. In this embodiment, it will be described that zinc (Zn) or aluminum (Al) is used as the anode 158. In addition, an alloy containing zinc or aluminum may be used as the anode 158. Additionally, vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), and copper (Cu) may be used as the anode 158, where acid or basic The solution may be used as the second electrolyte 155. A second connector 154 communicating with the second reaction space 151 is formed in the anode unit 150. The second connector 154 is positioned below the water surface of the second electrolyte 155, and the connection unit 190 is connected to the second connector 154.

The connection part 190 includes a connection passage 191 connecting the cathode part 110 and the anode part 150, and an ion transfer member 192 installed inside the connection passage 191.

The connection passage 191 extends between the first connector 114 formed on the cathode 110 and the second connector 154 formed on the anode 150 so that the first reaction space 111 of the cathode 110 ) And the second reaction space 151 of the anode 150 are communicated. The ion transfer member 192 is installed inside the connection passage 191.

The ion transfer member 192 is generally disk-shaped and is installed in a form of blocking the inside of the connection passage 191. The ion transfer member 192 is made of a porous structure and allows only the movement of ions between the cathode portion 110 and the anode portion 150. In this embodiment, the material of the ion transport member is described as glass, but the present invention is not limited thereto, and other materials having a porous structure may also be used, and this is also within the scope of the present invention. In this embodiment, the ion transfer member 192 has a pore size of 40 to 90 microns corresponding to a G2 grade (grade), 15 to 40 microns corresponding to a G3 grade, 5 to 15 microns corresponding to a G4 grade, Porous glass of 1 to 2 microns corresponding to G5 can be used. The ion transfer member 192 eliminates ion imbalance generated in the discharge process by transferring only ions.

Now, the discharge process of the secondary battery 100 described above with a focus on the configuration will be described in detail. 1 shows the discharge process of the secondary battery 100 together. Referring to FIG. 1, carbon dioxide gas is injected into the first electrolyte 115 through the first inlet 112, and a chemical elution reaction of carbon dioxide is performed in the cathode 110 as shown in [Scheme 1].

[Scheme 1]

_{H 2 O (l) + CO} 2 (g) → H + (aq) + HCO 3 - (aq)

That is, in the cathode part 110, the carbon dioxide gas (CO ₂ ) supplied to the cathode part 110 is hydrogen cation (H ⁺ ) and bicarbonate through spontaneous chemical reaction with water (H ₂ O) of the first electrolyte 115. (HCO ₃ ^-) is generated.

In addition, an electrical reaction as shown in [Reaction Scheme 2] is performed at the cathode unit 110.

[Scheme 2]

^{2H + (aq) + 2e -} → H 2 (g)

That is, in the cathode 110, hydrogen cations (H ⁺ ) receive electrons (e ⁻ ) and hydrogen gas (H ₂ ) is generated. The generated hydrogen gas is discharged to the outside through the first outlet 113.

In addition, a composite hydrogen generating reaction as shown in [Scheme 3] is performed at the cathode 110.

[Scheme 3]

_{2H 2 O (l) + 2CO} 2 (g) + 2e - → H 2 (g) + 2HCO 3 - (aq)

Then, in the anode unit 150, when the anode 158 is zinc (Zn), an oxidation reaction as shown in [Reaction Scheme 4] is performed.

[Scheme 4]

^{Zn + 4OH - → Zn (OH} ) 4 2 - + 2e - (E 0 = -1.25 V)

_{^{Zn (OH) 4 2 - →}} ZnO + H 2 O + 2OH -

As a result, when the anode 158 is zinc (Zn), the overall reaction equation made in the discharge process is as follows.

[Scheme 5]

Zn + 2CO _{2 ^{+ 2H 2 O + 2OH - →}} ZnO + 2HCO 3 - (aq) + H 2 (g) (E 0 = 1.25 V)

If, in the anode unit 150, the anode 158 is aluminum (Al), an oxidation reaction as shown in [Reaction Scheme 5] is performed.

[Scheme 5]

^{Al + 3OH - → Al (OH} ) 3 ^{+ 3e - (E 0 = -2.31} V)

As a result, when the anode 158 is aluminum (Al), the overall reaction equation made in the discharge process is as follows.

[Scheme 7]

2Al + 6CO _{2 ^{+ 6H 2 O + 6OH - →}} 2Al (OH) 3 ^{_{+ 6HCO 3 - (aq) +}} 3H 2 (g) (E 0 = 2.31 V)

As a result, as can be seen through [Scheme 6] and [Scheme 7], hydrogen ions generated by carbon dioxide eluted from the first electrolyte 115 during discharge receive electrons from the cathode 1 18 to generate hydrogen gas. It is reduced to, is discharged through the first outlet 113, the metal anode 158 is changed to the form of oxide.

FIG. 2 is a graph showing the results of half-cell experiments according to the temperature of the electrolytes 115 and 155 for the secondary battery of the embodiment shown in FIG. 1, and FIG. 3 discloses HER (hydrogen generation reaction) by temperature in the graph of FIG. 2 It is a graph showing the region, and FIG. 4 is a graph showing HER voltage for each temperature at a current density of 10 mA/cm 2 in the graph of FIG. 2.

2 to 4, the HER initiation region is improved from room temperature (RT) to 45°C as the temperature increases, and tends to decrease gradually after 45°C. In addition, when comparing the HER voltage at a current density of 10mA/cm 2, the performance improves as the temperature increases from room temperature (RT), but tends to be saturated from 60°C.

5 is a graph showing the results of a single cell experiment according to the temperatures of the electrolytes 115 and 155 for the secondary battery of the embodiment shown in FIG. 1. Referring to FIG. 5, it is confirmed that in the case of the cathode voltage in which the hydrogen generation reaction occurs, the tendency similar to the half cell performance results shown in FIGS. 2 to 4 is shown. In the case of the anode voltage in which the oxidation reaction occurs, the oxidation result is improved due to the temperature rise, and it is confirmed that the electrode oxidation performance is saturated in the temperature range of 70°C to 80°C. Therefore, when considering the performance of the cathode and the anode at the same time, it is confirmed that it exhibits excellent performance in the temperature range of the electrolyte at 60°C to 80°C, and the maximum current density at a temperature of 70°C is about 320mA/cm2, at room temperature It is confirmed that it shows the best performance by increasing about 2 times to about 160 mA/cm 2 measured. This is because the rate of the hydrogen generation reaction and the metal oxidation reaction is accelerated at the above temperature, and at a temperature exceeding 80° C., the rate of carbon dioxide dissolution reaction is slowed down, and the amount of dissolution is low, so that the performance decreases.

6 shows a discharge process of a configuration of a secondary battery for producing hydrogen using carbon dioxide according to a second embodiment of the present invention. Referring to FIG. 6, the secondary battery 100a includes a cathode unit 110, an anode unit 150, a connection unit 190 connecting the cathode unit 110 and the anode unit 150, and a carbon dioxide processing unit 120 ), the carbon dioxide circulation supply unit 130, the cathode 110 and the connection pipe 140 for communicating the carbon dioxide processing unit 120. The cathode unit 110, the anode unit 150, and the connection unit 190 are the same as those described in the embodiment illustrated in FIG. 1, and thus detailed description thereof will be omitted. The secondary battery 100a having the configuration shown in FIG. 6 also exhibits excellent performance at a temperature range of 60° C. to 80° C., more preferably 70° C., as described through FIGS. 2 to 5. Is done.

The carbon dioxide processing unit 120 includes a storage container 120a that provides a storage space 121 therein, and a first that is accommodated in the storage space 121 and is the same electrolyte solution as the first electrolyte solution 115 of the cathode 110. An electrolyte 115 is provided. The receiving container 120a is located at the upper portion of the receiving space 121, a second inlet 122 through which carbon dioxide gas flows into the receiving space 121, a communication port 123 to which the connecting pipe 140 is connected, and a receiving space 121. The second outlet 124 is formed.

The second inlet port 122 is located above the communication port 123 in the accommodation space 121, and is located below the water surface of the second outlet port 124 and the first electrolyte 115. Carbon dioxide gas used as a raw material in the discharge process is introduced into the receiving space 121 through the second inlet 122. The first electrolyte 115 may also be supplied as needed through the second inlet 122. The second inlet 122 and the first outlet 113 may be selectively opened and closed at a suitable time by a valve or the like during charging and discharging.

The communication port 123 is located below the second inlet port 122 in the accommodation space 121, and a connection pipe 140 is connected to the communication port 123. The accommodation space 121 communicates with the first reaction space 111 through the communication port 123.

The second outlet 124 is positioned above the water surface of the second inlet 122 and the first electrolyte 115 in the accommodation space 121. Carbon dioxide gas that is not ionized because it is not dissolved in the first electrolyte 115 in the receiving space 121 is discharged to the outside through the second outlet 124. The carbon dioxide gas discharged through the second outlet 124 is supplied to the second inlet 122 through the carbon dioxide circulation supply unit 130.

The carbon dioxide circulation supply unit 130 recirculates the carbon dioxide gas discharged through the second outlet 224 to the second inlet 122 to re-supply it.

The connector 140 connects the first inlet port 112 of the first reaction space 111 and the communication port 123 of the receiving space 121. The first reaction space 111 and the accommodation space 121 communicate with each other through a connection passage 141 formed inside the connection pipe 140.

Carbon dioxide gas that is not dissolved in the first electrolyte 115 among the carbon dioxide introduced into the accommodation space 121 of the carbon dioxide processing unit 120 through the second inlet 122 is not reacted with the first reaction space of the cathode 110 The carbon dioxide gas discharged through the second outlet 124 and discharged through the second outlet 124 after being collected in the space above the water surface of the first electrolyte 115 in the accommodation space 121 without being able to move to (111) Is supplied to the receiving space 121 through the second inlet 122 by the carbon dioxide circulation supply unit 130 is recycled. In addition, carbon dioxide gas that is not ionized because it is not dissolved in the first electrolyte 115 among the carbon dioxide introduced into the accommodation space 121 of the carbon dioxide processing unit 120 does not move to the first reaction space 111 of the cathode 110. Since it is not possible, high-purity hydrogen in which carbon dioxide is not mixed may be discharged through the first outlet 113.

The configuration of reference numerals not described in FIG. 6 is the same as the configuration indicated by the same reference numerals in the embodiment illustrated in FIG. 1.

7 is a schematic view illustrating a discharge process of a secondary battery according to a third embodiment of the present invention. Referring to FIG. 7, the secondary battery 200 includes a cathode part 210, an anode part 250, and a connection part 290 connecting the cathode part 210 and the anode part 250. The secondary battery 200 of the configuration shown in FIG. 7 also preferably exhibits excellent performance at a temperature range of 60° C. to 80° C., more preferably at a temperature of 70° C., as described through FIGS. 2 to 5. do.

The cathode unit 210 includes a first reaction vessel 110a providing a first reaction space 111 therein, a first electrolyte solution 215 contained in the first reaction space 111, and a first electrolyte solution 215. ) Is provided with a cathode (118) at least partially submerged. As the first electrolyte solution 215, an aqueous potassium hydroxide solution (in this embodiment, an elution of CO ₂ in a strong basic solution of 1M KOH is used) is used. Since the configuration of the first reaction vessel 110a and the cathode 118 is the same as the corresponding configuration in the embodiment illustrated in FIG. 1, detailed description thereof will be omitted.

The anode unit 250 includes a second reaction container 150a providing a second reaction space 151 therein, a second electrolyte solution 255 contained in the second reaction space 151, and a second electrolyte solution 255 ) Is provided with an anode 158 in which at least a part is locked. As the second electrolyte solution 255, it is described that an aqueous potassium hydroxide solution is used, for example, 1M KOH or 6M KOH can be used. Since the configuration of the second reaction vessel 150a and the anode 158 is the same as the corresponding configuration in the embodiment illustrated in FIG. 1, detailed description thereof will be omitted.

The connection part 290 includes a connection passage 191 connecting the cathode part 210 and the anode part 250, and an ion exchange membrane 292 installed inside the connection passage 191.

The connection passage 191 has the same configuration as the connection passage 191 illustrated in FIG. 1, and an ion exchange membrane 292 is installed inside the connection passage 191.

The ion exchange membrane 292 is installed in a form to block the inside of the connection passage 191. The ion exchange membrane 292 allows only the movement of ions between the cathode portion 210 and the anode portion 250. The potassium ion (K ⁺ ) contained in the second electrolyte solution 255 is moved to the first electrolyte solution 215 by the ion exchange membrane 292. In this embodiment, as the ion exchange membrane 292, it is described that a fluorine resin-based cation exchange membrane Nafion developed by DuPont, USA is used, but the present invention is not limited thereto, and potassium ions ( Anything that allows only the movement of K ⁺ ) is possible. The ion exchange membrane 292 eliminates ion imbalance generated in the discharge process by transferring only ions.

The configuration of reference numerals not described in FIG. 7 is the same as the configuration indicated by the same reference numerals in the embodiment illustrated in FIG. 1.

8 is a schematic diagram showing a discharge process of a secondary battery according to a fourth embodiment of the present invention. Referring to FIG. 8, the secondary battery 200a includes a cathode unit 210, an anode unit 250, a connection unit 290 connecting the cathode unit 210 and the anode unit 250, and a carbon dioxide processing unit 120 ), the carbon dioxide circulation supply unit 130, and the cathode 210 and the carbon dioxide processing unit 120 to communicate with the connecting pipe 140. The cathode unit 210, the anode unit 250, and the connection unit 290 are the same as those described in the embodiment shown in FIG. 7, and the carbon dioxide processing unit 120, the carbon dioxide circulation supply unit 130, and the connection pipe 140 are Since it is the same as the corresponding configuration shown in Figure 6, a detailed description thereof will be omitted. The secondary battery 200a of the configuration shown in FIG. 8 also preferably exhibits excellent performance at a temperature range of 60° C. to 80° C., more preferably 70° C., as described through FIGS. 2 to 5. do. The configuration of reference numerals not described in FIG. 8 is the same as the configuration indicated by the same reference numerals in the embodiment illustrated in FIG. 6.

9 is a schematic view illustrating a discharge process of a secondary battery according to a fifth embodiment of the present invention. Referring to FIG. 9, the secondary battery 300 includes a cathode part 210, an anode part 250, and a connecting part 390 connecting the cathode part 110 and the anode part 150. Since the cathode unit 210 and the anode unit 250 are the same as the corresponding components of the embodiment illustrated in FIG. 7, detailed description thereof will be omitted. The secondary battery 300 of the configuration shown in FIG. 9 also preferably exhibits excellent performance at a temperature range of 60° C. to 80° C., more preferably 70° C., as described through FIGS. 2 to 5. do.

The connection part 390 includes a connection passage 191 connecting the cathode part 210 and the anode part 250, and an ion exchange membrane 392 installed inside the connection passage 291.

The connection passage 191 is the same as the connection passage 191 of the embodiment shown in FIG. 7, and an ion exchange membrane 392 is installed inside the connection passage 191.

The ion exchange membrane 392 is installed in a form that blocks the inside of the connection passage 191. The ion exchange membrane 392 only allows the movement of ions between the cathode portion 210 and the anode portion 250. Through the ion exchange membrane 392, the hydroxide ions contained in the first electrolyte solution (215) (OH ^-) is moved in the second electrolyte 155. In this embodiment, as the ion exchange membrane 392, it is described that a fluorine resin-based cation exchange membrane Nafion developed by DuPont, USA is used, but the present invention is not limited thereto, and the hydroxide ion ( all as long as it is possible that only) movement of the ^- OH. Hydroxide ions by an ion exchange membrane (392) (OH ^-) is written doemeu delivered from the cathode 110 to the anode 150, thereby eliminating the ion imbalance caused in the discharge process.

The configuration of reference numerals not described in FIG. 9 is the same as the configuration indicated by the same reference numerals in the embodiment illustrated in FIG. 7.

10 is a schematic diagram showing a discharge process of a secondary battery according to a sixth embodiment of the present invention. Referring to FIG. 10, the secondary battery 300a includes a cathode unit 210, an anode unit 250, a connection unit 390 connecting the cathode unit 210 and the anode unit 250, and a carbon dioxide processing unit 120 ), the carbon dioxide circulation supply unit 130, and the cathode 210 and the carbon dioxide processing unit 220, the connecting pipe 140 for communicating. The cathode unit 210, the anode unit 250, and the connection unit 390 are the same as those described in the embodiment illustrated in FIG. 9, and the carbon dioxide processing unit 120, the carbon dioxide circulation supply unit 130, and the connection pipe 140 are Since it is the same as the corresponding configuration shown in FIG. 8, detailed description thereof will be omitted. The secondary battery 300a of the configuration shown in FIG. 10 also preferably exhibits excellent performance at a temperature range of 60° C. to 80° C., more preferably 70° C., as described through FIGS. 2 to 5. Is done. The configuration of reference numerals not described in FIG. 10 is the same as the configuration indicated by the same reference numerals in the embodiment illustrated in FIG. 8.

In the embodiment shown in FIGS. 1 and 6, a salt bridge connecting the first electrolyte 115 and the second electrolyte 155 may be used instead of the connecting portion 190, which is also within the scope of the present invention. Belong. When a salt bridge is used, an internal solution of a salt bridge commonly used, such as potassium chloride (KCl) and sodium chloride (NaCl), may be used as the internal solution of the salt bridge. When a salt bridge is used, as discharge proceeds, HCO ₃ ⁻ (bicarbonate ions) is generated in the first electrolyte 115, when the solution inside the salt bridge contains sodium ions (Na ⁺ ) such as sodium chloride (NaCl). , In order to balance the ions, sodium ions are diffused from the salt bridge and exist as ions in the form of an aqueous sodium hydrogen carbonate (NaHCO ₃ ) solution. When the solution is dried, a sodium carbonate solid product in the form of baking soda is additionally obtained.

11 is a schematic diagram showing a discharge process of a secondary battery according to a ninth embodiment of the present invention. Referring to FIG. 11, the secondary battery 500 includes a reaction vessel 510 providing a reaction space 511 therein, an electrolyte 515 as an aqueous electrolyte contained in the reaction space 511, and a reaction space 511. In at least a portion of the cathode 115 is immersed in the electrolyte 115, and the anode 158 is immersed in the aqueous electrolyte 115 in the reaction space 511. The secondary battery 500 uses the greenhouse gas carbon dioxide gas (CO ₂ ) as a raw material during the discharge process to produce hydrogen (H ₂ ), which is an eco-friendly fuel.

The reaction vessel 510 provides a reaction space 511 in which the electrolyte 515 is contained and the cathode 118 and the anode 158 are accommodated therein. The reaction vessel 510 is formed with a first inlet 512 and a first outlet 513 communicating with the reaction space 511. The first inlet 512 is positioned below the reaction space 511 so as to be positioned below the water surface of the electrolyte 515. The first outlet 513 is positioned above the reaction space 511 so as to be positioned above the water surface of the electrolyte 515. Carbon dioxide gas used as a raw material in the discharge process is introduced into the reaction space 511 through the first inlet 512, and an electrolyte 515 may also be introduced if necessary. Gas generated in the charging/discharging process is discharged to the outside through the first outlet 513. Although not shown, the first inlet 512 and the first outlet 513 may be selectively opened and closed in a timely manner by a valve or the like during charging and discharging. In the reaction space 511, a carbon dioxide elution reaction occurs in the discharge process.

The electrolyte 515, which is an aqueous electrolyte, is contained in the reaction space 511, and at least a portion of the cathode 118 and at least a portion of the anode 158 are immersed in the electrolyte 515. In this embodiment, it will be described that a basic solution or seawater is used as the electrolyte 115. The electrolyte 515 becomes weakly acidic by the carbon dioxide gas flowing through the first inlet 512 during the discharge process.

The cathode 118 is at least partially immersed in the electrolyte 515 in the reaction space 511. The cathode 118 is positioned relatively closer to the first inlet 512 than the anode 158 in the reaction space 511. The cathode 118 is an electrode for forming an electrical circuit, and may be carbon paper, carbon fiber, carbon felt, carbon cloth, metal foam, metal thin film, or a combination thereof, and a platinum catalyst may also be used. In the case of the catalyst, in addition to the platinum catalyst, all other catalysts that can be generally used as a hydrogen generation reaction (HER) catalyst, such as a carbon-based catalyst, a carbon-metal-based composite catalyst, and a perovskite oxide catalyst, are also included. During discharge, a reduction reaction occurs at the cathode 118, and hydrogen is generated accordingly.

The anode 158 is at least partially submerged in the electrolyte 515 in the reaction space 511. The anode 158 is positioned relatively far from the first inlet 512 than the cathode 118 in the reaction space 511. The anode 158 is an electrode of a metal material constituting an electrical circuit, and in this embodiment, as the anode 158, vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), and nickel It will be described that (Ni), copper (Cu), aluminum (Al) or zinc (Zn) is used. During discharge, an oxidation reaction according to a weakly acidic environment occurs at the anode 158.

The secondary battery 500 of the configuration shown in FIG. 11 also preferably exhibits excellent performance at a temperature range of 60° C. to 80° C., more preferably 70° C., as described through FIGS. 2 to 5. do.

Now, the discharge process of the secondary battery 100 described above with a focus on the configuration will be described in detail. 11 shows the discharge process of the secondary battery 500 together. Referring to FIG. 11, carbon dioxide gas is injected into the electrolyte solution 515 through the first inlet 512 during discharge, and a chemical elution reaction of carbon dioxide as in [Reaction Scheme 1] is performed in the reaction space 511. That is, the carbon dioxide supplied to the reaction chamber (511) (CO ₂₎ is water (H ₂ O) and spontaneous hydrogen cations through a chemical reaction (H ⁺⁾ and bicarbonate in the electrolyte (515) (HCO ₃ ^-) is generated.

In addition, an electrical reaction such as [Scheme 2] is performed at the cathode 118. That is, hydrogen cations (H ⁺ ) around the cathode 118 receive electrons (e ⁻ ) from the cathode 118 and hydrogen (H ₂ ) gas is generated. The generated hydrogen (H ₂ ) gas is discharged to the outside through the first outlet 513.

In addition, a complex hydrogen generating reaction such as [Scheme 3] is performed around the cathode 118.

Then, in the anode 158, when the anode 158 is zinc (Zn), an oxidation reaction as shown in [Reaction Scheme 4] is performed.

As a result, when the anode 158 is zinc (Zn), the overall reaction formula formed in the discharge process is the same as [Reaction Scheme 5].

If, when the anode 158 is aluminum (Al), an oxidation reaction as shown in [Scheme 6] is performed.

As a result, when the anode 158 is aluminum (Al), the overall reaction equation formed in the discharge process is the same as [Scheme 7].

As a result, hydrogen ions generated by carbon dioxide eluted from the electrolyte 515, which is an aqueous electrolyte during discharge, receives electrons from the cathode 118 and is reduced to hydrogen gas, discharged through the first outlet 513, and is a metal anode 158 is changed to an oxide form.

12 is a schematic diagram showing a discharge process of a secondary battery according to a tenth embodiment of the present invention. Referring to FIG. 12, the secondary battery 500a includes a reaction vessel 510 providing a reaction space 511 therein, an electrolyte solution 515 contained in the reaction space 511, and an electrolyte solution in the reaction space 511 ( Cathode 118 at least partially immersed in 515, anode 158 at least partially immersed in electrolyte 515 in reaction space 511, carbon dioxide processing unit 120, and carbon dioxide circulation supply unit 130, and a connection pipe 140 for connecting the reaction vessel 510 and the carbon dioxide treatment unit 120. The reaction vessel 510, the electrolyte 515, the cathode 118, and the anode 158 are the same as each of the corresponding configurations described in the embodiment shown in FIG. 11, and the carbon dioxide processing unit 120, the carbon dioxide circulation supply unit ( 130) and the connector 140 are the same as each of the corresponding components shown in FIG. 6, so detailed description thereof will be omitted. The secondary battery 500a of the configuration shown in FIG. 12 also exhibits excellent performance at a temperature range of 60° C. to 80° C., more preferably 70° C., as described through FIGS. 2 to 5. Is done.

13 is a view showing a schematic configuration of a complex power generation system having a secondary battery for producing hydrogen using carbon dioxide according to an embodiment of the present invention. Referring to FIG. 13, the combined power generation system 1000 according to an embodiment of the present invention includes a secondary battery 100 that generates hydrogen gas (H ₂ ) using carbon dioxide gas (CO ₂ ) as a raw material during a discharge process, A reformer 300 that produces hydrogen-rich reformed gas from hydrogen-containing fuel and additionally generates carbon dioxide gas (CO ₂ ), a fuel cell 200 that generates electricity using hydrogen and oxygen, and a reformer 300 ) Produced by the carbon dioxide supply unit 400 for supplying the carbon dioxide gas generated in the secondary battery 100, the hydrogen supply unit 500 for supplying the hydrogen gas generated in the secondary battery 100 to the fuel cell, and the reformer 300 It includes a reforming gas supply unit 600 for supplying the reformed gas to the fuel cell 200.

The secondary battery 100 is a secondary battery 100 previously described with reference to FIG. 1, and uses carbon dioxide gas as a raw material in the discharge process and generates hydrogen gas as described in detail with reference to FIG. 1. The carbon dioxide gas supplied to the secondary battery 100 is carbon dioxide gas generated from the reformer 300 and supplied through the carbon dioxide supply unit 400. The hydrogen gas generated in the secondary battery 100 is supplied to the fuel cell 200 by the hydrogen supply unit 500. In this embodiment, although the secondary battery 100 shown in FIG. 1 is described as being used in a combined power generation system, alternatively, the secondary battery of the embodiment shown in FIGS. 6 to 12 may be used, which is also the scope of the present invention. It belongs to.

The reformer 300 produces hydrogen-rich reformed gas from a hydrogen-containing fuel and additionally generates carbon dioxide gas. To this end, in this embodiment, the reformer 300 is described as a methane-steam reformer that produces hydrogen (H ₂ ) by a reforming reaction of methane (CH ₄ ) and water vapor (H ₂ O).

The methane-steam reformer 300 occupies a considerable portion of the hydrogen production process because of the advantages of low process cost and mass production. The following [Scheme 8] relates to the reforming reaction of the methane-steam reformer 300.

[Scheme 8]

CH ₄ + H ₂ O -> CO + 3H ₂

CO + H ₂ O -> CO ₂ + H ₂

That is, carbon monoxide (CO) and hydrogen are produced by the chemical reaction between methane and water vapor, and hydrogen can be finally produced by the chemical reaction between carbon monoxide and water vapor. Hydrogen produced in the methane-steam reformer 300 is supplied to the fuel such as the fuel cell 200 by the reforming gas supply unit 600.

However, the methane-steam reformer 300 has many advantages described above, but as can be seen from [Scheme 8], water must be supplied from outside for the operation of the process, and global warming is a byproduct of hydrogen production. There is a problem that carbon dioxide, which is a main cause of environmental problems, is forced to be generated. However, in the present invention, the carbon dioxide generated in the methane-steam reformer 300 is discharged into the atmosphere or transferred to a separate carbon dioxide capture and storage process, instead of being supplied to the carbon dioxide supply unit 400 for the discharge reaction of the secondary battery 100 By being delivered to the water-based secondary battery 100, it is possible to solve the carbon dioxide generation problem, which is a necessary evil in the operation of the methane-steam reformer 300, as well as a system that links the secondary battery 100 and the methane-steam reformer 300 By constructing the, duplicate process can be omitted. Since the methane-steam reformer 300 is a known technique, detailed description thereof is omitted here.

The fuel cell 200 is to generate water and generate electric energy by the chemical reaction of hydrogen and oxygen. The fuel cell 200 has many advantages in terms of eco-friendliness, but must be supplied with hydrogen extracted from the methane-steam reformer 300 and the like. However, in the case of the present invention, the fuel cell 200 is constructed as one system with the secondary battery 100, so that hydrogen gas generated during the discharge process of the secondary battery 100 is supplied, so that efficiency can be significantly improved. .

The carbon dioxide supply unit 400 supplies carbon dioxide gas generated as a by-product in the reformer 300 to the secondary battery 100.

The hydrogen supply unit 500 supplies hydrogen gas generated as a by-product in the discharge process of the secondary battery 100 as fuel of the fuel cell 200.

The reforming gas supply unit 600 supplies the reformed gas produced by the reformer 300 as fuel of the fuel cell 200.

The present invention has been described through the above embodiments, but the present invention is not limited thereto. The above embodiments may be modified or changed without departing from the spirit and scope of the present invention, and those skilled in the art will recognize that such modifications and changes also belong to the present invention.

100, 100a: secondary battery 110: cathode portion
111: first receiving space 112: first inlet
113: first outlet 115: first aqueous solution
118: cathode 120: carbon dioxide treatment unit
121: third receiving space 122: second inlet
123: communication port 124: second outlet
130: carbon dioxide circulation supply unit 140: connector
150: anode 151: the second accommodation space
155 second aqueous solution 158 anode
190: connecting portion 191: connecting passage
192: absence of ion transfer

Claims (18)

In the secondary battery capable of charging and discharging,
A cathode unit including a first electrolyte solution that is an aqueous electrolyte accommodated in a first reaction space and a cathode at least partially submerged in the first electrolyte solution; And
And an anode portion having a second electrolyte solution that is an aqueous electrolyte accommodated in the second reaction space and an anode at least partially submerged in the second electrolyte solution,
In the discharge process, the temperature of the first electrolyte solution and the second electrolyte solution is maintained at 60°C to 80°C, and carbon dioxide gas flows into the first electrolyte solution, and is reacted by the reaction of water and the carbon dioxide gas in the first electrolyte solution. A secondary battery in which hydrogen ions and bicarbonate ions are generated, and hydrogen gas is generated by combining electrons of the hydrogen ions and the cathode. In the secondary battery capable of charging and discharging,
A cathode unit including a first electrolyte solution that is an aqueous electrolyte accommodated in a first reaction space and a cathode at least partially submerged in the first electrolyte solution;
A carbon dioxide treatment unit having the first electrolyte solution accommodated in an accommodation space communicating with the first reaction space; And
And an anode portion having a second electrolyte solution that is an aqueous electrolyte accommodated in the second reaction space and an anode at least partially submerged in the second electrolyte solution,
In the discharge process, the temperature of the first electrolyte and the second electrolyte is maintained at 60°C to 80°C, carbon dioxide gas is introduced into the first electrolyte solution in the accommodation space, and water and the carbon dioxide gas of the first electrolyte solution Hydrogen ions and bicarbonate ions are generated by the reaction of, and hydrogen gas is generated by combining the hydrogen ions and electrons of the cathode at the cathode,
The carbon dioxide processing unit is a secondary battery to prevent the non-ionized carbon dioxide gas among the carbon dioxide gas flowing into the first electrolyte in the receiving space from being supplied to the cathode by separating it from the first electrolyte. The method according to claim 1 or claim 2,
In the discharge process, the temperature of the first electrolyte and the second electrolyte is maintained at 70 ℃ secondary battery. The method according to claim 1 or claim 2,
Further comprising a connection passage communicating the first reaction space and the second reaction space, and an ion transfer member having a porous structure installed in the connection passage to allow only ions to move between the first electrolyte solution and the second electrolyte solution Secondary battery. The method according to claim 4,
The material of the ion transfer member is a secondary battery made of glass. The method according to claim 1 or claim 2,
A secondary battery further comprising a connection passage communicating the first reaction space and the second reaction space, and an ion exchange membrane installed in the connection passage to allow only ions to move between the first electrolyte solution and the second electrolyte solution. . The method according to claim 6,
The first electrolyte solution and the second electrolyte solution are potassium hydroxide aqueous solutions,
The ion exchange membrane is a secondary battery that allows potassium ions to move from the second reaction space to the first reaction space. The method according to claim 6,
The first electrolyte solution and the second electrolyte solution are potassium hydroxide aqueous solutions,
The ion exchange membrane is a secondary battery that allows hydroxide ions to move from the first reaction space to the second reaction space. The method according to claim 1 or claim 2,
The anode material is a secondary battery including at least one metal selected from the group consisting of zinc, aluminum, vanadium, chromium, manganese, iron, cobalt, nickel, and copper. In the secondary battery capable of charging and discharging,
An electrolyte that is an aqueous electrolyte accommodated in the reaction space;
A cathode immersed in at least a portion of the electrolyte solution; And
It includes an anode at least partially submerged in the electrolyte,
During the discharge process, the temperature of the electrolyte is maintained at 60°C to 80°C, carbon dioxide gas is introduced into the electrolyte, and hydrogen ions and bicarbonate ions are generated by the reaction of water and the carbon dioxide gas in the electrolyte, and the hydrogen A secondary battery in which hydrogen gas is generated by combining ions and electrons of the cathode. In the secondary battery capable of charging and discharging,
An aqueous electrolyte that is accommodated in a reaction space and a receiving space communicating with the reaction space;
A cathode in which at least a part is immersed in the electrolyte solution in the reaction space; And
And an anode at least partially submerged in the electrolyte solution in the reaction space,
During the discharge process, the temperature of the electrolyte is maintained at 60°C to 80°C, and carbon dioxide gas is introduced into the electrolyte solution in the receiving space, whereby hydrogen ions and bicarbonate ions are generated by reaction of water and the carbon dioxide gas in the electrolyte solution, , In the reaction space, the hydrogen ions and electrons of the cathode are combined to generate hydrogen gas,
Among the carbon dioxide gas flowing into the aqueous electrolyte in the accommodation space, the non-ionized carbon dioxide gas is separated from the electrolyte in the accommodation space and is not supplied to the reaction space. The method according to claim 10 or claim 11,
In the discharge process, the temperature of the electrolyte is maintained at 70 ℃ secondary battery. The method according to claim 10 or claim 11,
The anode material is a secondary battery including at least one metal selected from the group consisting of zinc, aluminum, vanadium, chromium, manganese, iron, cobalt, nickel, and copper. A secondary battery that generates hydrogen by using carbon dioxide as a fuel in the discharge process;
A reformer that produces hydrogen-rich reformed gas from hydrogen-containing fuel and generates carbon dioxide as a by-product;
A fuel cell receiving reformed gas produced from the reformer as fuel; And
It includes a carbon dioxide supply for supplying the carbon dioxide generated in the reformer to the secondary battery,
The secondary battery is a composite power generation system that is a secondary battery according to any one of claims 1, 2, 10 and 11. The method according to claim 14,
Combined power generation system further comprises a hydrogen supply for supplying the hydrogen generated in the secondary battery to the fuel of the fuel cell. A secondary battery that generates hydrogen by using carbon dioxide as a fuel in the discharge process;
A reformer producing a reforming gas rich in hydrogen from a hydrogen-containing furnace;
A fuel cell receiving reformed gas produced from the reformer as fuel; And
It includes a hydrogen supply unit for additionally supplying the hydrogen generated in the secondary battery to the fuel of the fuel cell,
The secondary battery is a composite power generation system that is a secondary battery according to any one of claims 1, 2, 10 and 11. A secondary battery that generates hydrogen by using carbon dioxide as a fuel in the discharge process;
A reformer that produces hydrogen-rich reformed gas from hydrogen-containing fuel and generates carbon dioxide as a by-product;
A fuel cell receiving reformed gas produced from the reformer as fuel;
A carbon dioxide supply unit supplying carbon dioxide generated in the reformer to the secondary battery; And
It includes a hydrogen supply unit for additionally supplying the hydrogen generated in the secondary battery to the fuel of the fuel cell,
The secondary battery is a composite power generation system that is a secondary battery according to any one of claims 1, 2, 10 and 11. The method according to claim 17,
The reformer is a combined power generation system that is a methane-steam reformer that produces hydrogen by the reforming reaction of methane (CH ₄ ) and water vapor (H ₂ O).

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