LIQUID METAL BATTERY AND SYSTEM FOR HYDROGEN PRODUCTION AND CARBON DIOXIDE STORAGE USING THIS BATTERY

Abstract

Provided are a liquid metal battery and a system for hydrogen production and carbon dioxide storage comprising this battery. The liquid metal battery may comprise a dual cell. The dual cell may comprise a pair of individual cells. Each of the individual cells has an anode, a cathode, a separator disposed between the anode and the cathode, and a cathode spacer disposed between the separator and the cathode and configured to form a gap between the separator and the cathode. The dual cell may also comprise a current collector disposed between the pair of individual cells such that the cathodes of the individual cells face each other across the current collector.

Description

BACKGROUNDTechnical field

[0001] The present disclosure relates to a liquid metal battery or metal-aqueous battery and a system for hydrogen production and carbon dioxide storage comprising this battery. background

[0002] Recently, electrochemical water electrolysis has been intensively researched in line with the development of renewable energies to address climate change. In addition, the technology for the capture, storage, and conversion of carbon dioxide (CO 2 ) to reduce greenhouse gases is becoming increasingly important.

[0003] Aqueous battery systems or liquid battery systems based on zinc / aluminum (Zn / Al) use very economical metal anode candidates in terms of price and reserves. Aqueous battery system based on zinc / aluminum (Zn / Al) is a system that produces hydrogen and simultaneously releases carbon dioxide in the form of a salt such as KHCO 3 etc.

[0004] However, since a liquid metal battery known from the state of the art is a single cell consisting of an anode and a cathode, as well as a stack based on it, the current that can be achieved is limited. PRESENTATION OF REVELATION

[0005] An object of the present disclosure is to provide a liquid metal battery with improved power generation amount and power generation rate.

[0006] An object of the present disclosure is to provide a liquid metal battery capable of preventing an anode from being passivated.

[0007] The objects of the present disclosure are not limited to the foregoing. The objects of the present disclosure can be clearly understood from the following description and can be realized by the means described in the claims and combinations thereof.

[0008] In one aspect, a liquid metal battery is provided, the battery comprising: a) a double cell comprising: i) a pair of single cells, each of the single cells comprising: an anode and a cathode, and ii) a separator disposed between the anode and the cathode, and b) a cathode spacer disposed between the separator and the cathode and configured to form a gap between the separator and the cathode; and c) a current collector disposed between the pair of single cells such that cathodes of the single cells face each other across the current collector.

[0009] An exemplary embodiment of the present disclosure provides a liquid metal battery having a dual cell configured such that a current collector is disposed between a pair of individual cells each having an anode, a cathode, and a separator disposed between the anode and the cathode such that the cathodes of the individual cells face each other across the current collector, wherein each of the individual cells may have a cathode spacer disposed between the separator and the cathode and configured to form a gap between the separator and the cathode.

[0010] Each of the single cells may further comprise a plate in a panel shape having a predetermined thickness, having a first main surface and a second main surface opposite to the first main surface, disposed on an outer surface of the single cell and having an interior space open to the first main surface.

[0011] The anode can be accommodated in the interior.

[0012] The separator can be stacked on the first main surface to cover an open area of ​​the interior.

[0013] The plate may have a first electrolyte inlet formed in a portion of a side surface and configured to communicate with the internal space, and a first electrolyte outlet formed at a position spaced from the first electrolyte inlet by a predetermined distance and configured to communicate with the internal space.

[0014] The anode may be in the form of a pellet, each of the single cells may further include a support provided obliquely in the inner space and having a plurality of through holes, the anode may be accommodated between the inner surface of the plate and the support, and a diameter of the through holes may be smaller than a diameter of the anode.

[0015] The anode may be in the form of a plate, and each of the individual cells may further comprise a pressing member received in the interior space and provided between the inner surface of the plate and the anode to exert a pressing force to move the anode toward the separator.

[0016] The anode may comprise at least one of the group consisting of lithium (Li), sodium (Na), magnesium (Mg), zinc (Zn), aluminum (Al), and a combination thereof.

[0017] The liquid metal battery may further include a wire configured to electrically connect the anode and the current collector.

[0018] The cathode may comprise a noble metal catalyst loaded onto a support.

[0019] The liquid metal battery may further comprise a separator spacer disposed between the plate and the separator, having a predetermined thickness, and having a frame shape with a central portion open, in which the separator spacer can support an edge of the separator to expand the interior space of the plate by a thickness of the separator spacer.

[0020] The liquid metal battery may further comprise a protective layer having a shape corresponding to the open surface of the plate, provided on the open surface of the plate, and being porous.

[0021] The separator may comprise a material with cation conductivity or a material with anion conductivity.

[0022] The cathode spacer may have a frame shape with a central portion open and may support an edge of the separator to form the gap, and the cathode spacer may have a second electrolyte inlet formed in a portion of a side surface of the cathode spacer and configured to communicate with the gap, and a second electrolyte outlet formed in a portion of a side surface of the cathode spacer spaced from the second electrolyte inlet by a predetermined distance and configured to communicate with the gap.

[0023] The liquid metal battery may further comprise a first electrolyte accommodated in the interior of the plate and a second electrolyte accommodated in the gap.

[0024] The first electrolyte may comprise an alkali metal hydride.

[0025] The second electrolyte can contain protons and bicarbonate ions.

[0026] The temperature of the first electrolyte can be about 40 °C to about 80 °C.

[0027] The temperature of the second electrolyte can be about 40 °C to about 80 °C.

[0028] The temperature of the first electrolyte may be equal to or higher than the temperature of the second electrolyte.

[0029] The liquid metal battery may include a stack configured such that a plurality of double cells are stacked.

[0030] Another embodiment of the present disclosure provides a hydrogen generation and carbon dioxide storage system comprising the liquid metal battery described above, a first electrolyte supply unit configured to supply a first electrolyte to the liquid metal battery, a second electrolyte supply unit configured to supply a second electrolyte to the liquid metal battery, a first heater disposed between the liquid metal battery and the first electrolyte supply unit, and a second heater disposed between the liquid metal battery and the second electrolyte supply unit.

[0031] The first heating unit may suitably comprise a first heat exchanger configured to exchange heat between the first electrolyte and a heat source, and the second heating means may comprise a second heat exchanger configured to exchange heat between the second electrolyte and a heat source. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and other features of the present disclosure will now be described in detail with reference to certain exemplary embodiments illustrated in the accompanying drawings, which are given below for illustrative purposes only and therefore do not limit the present disclosure: Fig. 1 shows a first embodiment of a liquid metal battery according to the present disclosure; Fig. 2 shows electrolyte flow of the liquid metal battery according to the present disclosure; Fig. 3 shows a plate according to the present disclosure; Fig. 4A shows a first embodiment of a carrier according to the present disclosure; Fig. 4B shows a second embodiment of the carrier according to the present disclosure; Fig. 4C shows a third embodiment of the carrier according to the present disclosure; Fig. 5 shows a second embodiment of the liquid metal battery according to the present disclosure; Fig. 6 shows a cathode spacer according to the present disclosure; Fig. 7 shows a stack according to the present disclosure; Fig. 8 shows a system for hydrogen production and carbon dioxide storage according to the present disclosure; Fig. 9 shows a discharge diagram of a liquid metal battery with a double cell, DC, structure and a liquid metal battery with a single cell, SC, structure in Test Example 1; Fig. 10 shows a discharge curve versus current density of the liquid metal battery at different temperatures of the first electrolyte in Test Example 2; Fig. 11 shows a discharge diagram, as a function of time, of the liquid metal battery at different temperatures of the first electrolyte in Test Example 2; Fig. 12 shows results of evaluation of the liquid metal battery at different temperatures of the second electrolyte in Test Example 3; and Fig. 13 shows a discharge curve of the liquid metal battery under conditions 1 to 3 in Test Example 4. DETAILED DESCRIPTION

[0033] The above and other objects, features, and advantages of the present disclosure will become more clearly understood from the following preferred embodiments taken in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed herein and may be modified in various forms. These embodiments are provided to thoroughly describe the disclosure and to sufficiently convey the spirit of the present disclosure to those skilled in the art.

[0034] In the drawings, the same reference numerals refer to the same or similar elements. In the interest of clarity of the present disclosure, the dimensions of the structures are shown larger than their actual sizes. It should be noted that although terms such as "first," "second," etc., may be used herein to describe various elements, these elements are not intended to be limited by these terms. These terms are used only to distinguish one element from another. For example, a "first" element described below could be referred to as a "second" element without departing from the scope of the present disclosure. Similarly, the "second" element could also be referred to as a "first" element.

[0035] When an element such as a layer, film, surface, or panel is described as being "on top of" another element, it may be directly on top of the other element, or there may be intervening elements. When an element such as a layer, film, surface, or panel is described as being "under" another element, it may be directly beneath the other element, or there may be intervening elements.

[0036] It is noted that the term "vehicle" or a similar term, when used herein, encompasses motor vehicles in general, such as passenger cars, including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft, including a variety of boats and ships, aircraft, and the like, as well as hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). A hybrid vehicle is a vehicle that has two or more power sources, for example, both gasoline-powered and electric-powered vehicles.

[0037] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" include the plural forms as well, unless the context clearly indicates otherwise. These terms are used solely to distinguish one component from another, and the terms do not limit the type, order, or order of the individual components. It is further noted that the terms "comprising" and / or "having," when used in this specification, specify the presence of certain features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.When used herein, the term "and / or" includes any and all combinations of one or more of the associated listed elements. Unless expressly described otherwise, the word "comprise" and variations such as "comprises" or "comprising" are intended to mean the inclusion of the listed elements and not the exclusion of others. In addition, the terms "unit," "-er," "-or," and "module" described in the specification refer to units for performing at least one function and operation and may be implemented by hardware components or software components, and combinations thereof.

[0038] Although exemplary embodiments are described as having a plurality of units for performing the exemplary process, the exemplary processes may also be performed by one or more modules. Furthermore, the term controller / controller is understood to refer to a hardware device having a memory and a processor and specifically programmed to execute the processes described herein. The memory is configured to store the modules, and the processor is configured to execute the modules to perform one or more processes described further below.

[0039] Furthermore, the control logic of the present disclosure may be embodied as a non-transitory computer-readable medium on a computer-readable medium containing executable program instructions executed by a processor, controller, or the like. Examples of computer-readable media include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash drives, smart cards, and optical data storage devices. The computer-readable medium may also be distributed in network-coupled computer systems such that the computer-readable medium is stored and executed in a distributed manner, for example, by a telematics server or a controller area network (CAN).

[0040] Unless expressly stated or clear from the context, the term "about" is understood herein to mean within a normal range of tolerance, for example, within 2 standard deviations of the mean. "About" can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless the context otherwise indicates, all numerical values ​​stated herein are modified by the term "about."

[0041] Unless otherwise stated, all numbers, values ​​and / or representations expressing the amounts of ingredients, reaction conditions, polymer compositions and blends used herein are to be understood as approximate values ​​that include various measurement uncertainties that, among other things, occur in the determination of these values ​​and should therefore be modified in all cases by the term "about". When a range of numbers is given in this description, it is continuous and includes all values ​​from the minimum value of the range to its maximum value, unless otherwise stated. Furthermore, when such a range refers to integer values, all integer values ​​including the minimum value up to the maximum value are included, unless otherwise stated.

[0042] Fig. Figure 1 shows a first embodiment of a liquid metal battery according to the present disclosure. For ease of description and understanding, a first electrolyte A and a second electrolyte B are shown in Fig. 1 not shown. Fig. 2 shows the electrolyte flow of the liquid metal battery according to the present disclosure.

[0043] The liquid metal battery may comprise a double cell DC configured such that a current collector CC is disposed between a pair of single cells SC, each having an anode 30, a cathode 50, and a separator 40 disposed between the anode 30 and the cathode 50 such that the cathodes 50 of the single cells face each other.

[0044] The current collector CC can be made of an electrically conductive material. For example, the current collector CC can be made by coating a thin stainless steel sheet with gold (Au).

[0045] With reference to Fig. 1 and Fig. 2, each single cell SC may include a plate 10, a sheet-like support 20 provided in an interior space 14 of the plate 10, an anode 30 received between the plate 10 and the support 20, a separator 40 stacked on the plate 10, a first electrolyte A received in the interior space 14 of the plate 10, a cathode 50 disposed on the separator 40, a cathode spacer 60 disposed between the separator 40 and the cathode 50 and configured to form a gap G between the separator 40 and the cathode 50, and a second electrolyte B received in the gap G.

[0046] Fig. 3 shows the plate 10. The plate 10 may be in the form of a panel with a predetermined thickness, having a first main surface 11, a second main surface 12 facing the first main surface 11, and side surfaces 13 connecting the first main surface 11 and the second main surface 12.

[0047] The plate 10 may be made of a material with excellent physical properties without electrical conductivity. For example, the plate 10 may be made of polycarbonate.

[0048] The plate 10 may have an interior space 14 open toward the first main surface 11. The interior space 14 open toward the first main surface 11 means that a portion of the first main surface 11 is open to form an open area 11a, so that the interior space 14 communicates with the exterior.

[0049] The plate 10 may have an opening 15 formed in a portion of the side surface 13 to allow the interior 14 to communicate with the exterior. For example, an opening 15 may be provided in a portion of the top surface of the plate 10, as shown in Fig. 1. The anode 30 can be fed into the interior space 14 through the opening 15.

[0050] The liquid metal battery may further include a stopper D detachably attached to the opening 15. The size of the stopper D is not specifically limited, provided the stopper is capable of completely closing the opening 15 to prevent the interior 14 from contacting the exterior. The stopper D may also be made of a material that is incapable of reacting with the first electrolyte A and the anode 30.

[0051] The plate 10 may have a first electrolyte inlet 16 formed through a portion of the side surface 13 and configured to communicate with the interior space 14, and a first electrolyte outlet 17 formed through a portion of the side surface spaced from the first electrolyte inlet 16 by a predetermined distance and configured to communicate with the interior space 14. As shown in Fig. For example, as shown in Figure 1, the first electrolyte inlet 16 may be provided in the lower side surface 13 and the first electrolyte outlet 17 may be provided in the upper side surface 13. Likewise, the plate 10 may have a plurality of first electrolyte inlets 16 and a plurality of first electrolyte outlets 17.

[0052] Fig. 4A shows a first embodiment of the carrier 20. As in Fig. As shown in Figure 1, the support 20 may be arranged at an angle so that the space in which the anode 30 is accommodated becomes narrower toward the bottom. When the anode 30 is reduced in size by ionization, it accumulates at the lower position. Accordingly, the contact area between the anode 30 and the support 20 is increased, so that ionization of the anode 30 can occur more easily. When the contact area between the anode 30 and the support 20 is increased, the ionization area can be increased, and thus the current density of the battery can increase.

[0053] The support 20 may comprise an electrically conductive metal. The support 20 may also comprise a material having a rigidity capable of withstanding the weight of the anode 30. The support 20 may, for example, comprise a stainless steel mesh.

[0054] The liquid metal battery may include a wire 70 configured to electrically connect the substrate 20 and the current collector CC. The electrical connection configuration is not specifically limited. For example, a lead L may be attached to the inner surface of the opening 15 of the plate 10 so that one end thereof is exposed to the outside, and one end of the substrate 20 may be provided to contact the lead L, after which a wire 70 may be connected to one end of the lead L.

[0055] The carrier 20 may have a plurality of through-holes 21. The first electrolyte A may move across the through-holes 21.

[0056] Since the support 20 must prevent the anode 30 from leaving the space between the plate 10 and the support 20, the diameter of the through holes 21 may be smaller than that of the anode 30. In particular, the diameter of the through holes 21 may be 0.5 mm to 2 mm.

[0057] Fig. Figure 4B shows a second embodiment of the support 20. In a preferred embodiment, the support 20 is configured such that the diameter of the through-holes 21 decreases downwards. This is because the anode 30, which shrinks during the reaction and moves downwards, is prevented from passing through the through-holes 21.

[0058] Fig. Figure 4C shows a third embodiment of the support 20. The underside of the support 20 does not need to have through-holes 21. This allows a reaction to be initiated quickly by increasing the contact area of ​​the anode, which decreases during the reaction, with the support on the underside.

[0059] The anode 30 may be made of any material capable of generating electrons by being ionized in the first electrolyte, and may, for example, comprise at least one selected from the group consisting of lithium (Li), sodium (Na), magnesium (Mg), zinc (Zn), aluminum (Al), and combinations thereof. Preferably, the anode 30 comprises at least one selected from the group consisting of magnesium (Mg), zinc (Zn), aluminum (Al), and combinations thereof. Magnesium (Mg), zinc (Zn), and aluminum (Al) are stable in water and are preferred in aqueous systems. Preferably, the anode 30 comprises at least one selected from the group consisting of zinc (Zn), aluminum (Al), and combinations thereof. Zinc (Zn) and aluminum (Al) are highly desirable given global reserves and prices.

[0060] The anode 30 may be in the form of a spherical, elliptical, cylindrical, etc. pellet. When the anode 30 is elliptical, its diameter is the length of a major axis. When the anode 30 is cylindrical, its diameter is the diameter of the base side. The diameter of the anode 30 can be 3 mm to 10 mm. If the diameter of the anode 30 is less than 3 mm, it may pass through the through holes 21 due to the reduced size caused by ionization. On the other hand, if the diameter of the anode 30 exceeds 10 mm, the specific surface area of ​​the anode 30 may decrease, and therefore the performance of the liquid metal battery may deteriorate.

[0061] Fig. 5 shows a second embodiment of the liquid metal battery according to the present disclosure. In contrast to Fig. 1, the anode 30 can be Fig. 5 in the form of a panel or a flat structure.

[0062] The liquid metal battery may include a pressure member 600 received in the interior space 14 of the plate 10 and provided between the inner surface of the plate 10 and the anode 30 to exert a pressure force to move the anode 30 toward the separator 40.

[0063] Here, the anode 30 may be configured such that a plurality of sheets are stacked and accommodated between the pressure part 600 and the separator 40.

[0064] The pressing member 600 may press the anode 30 toward the separator 40 so that those among the plates of the anode 30 that are close to the separator 40 react and are consumed first.

[0065] The pressing part 600 may include a support plate 610 configured to press the anode 30 and an elastic member 620 provided between the support plate 610 and the plate 10 to exert an elastic force on the support plate 610.

[0066] When those among the plates of the anode 30 that are close to the separator 40 are consumed by reaction, the support plate 610 presses the anode 30 by the elastic force of the elastic member 620. Therefore, the anode 30 can be positioned close to the separator 40.

[0067] The liquid metal battery may further include a separator spacer 80 disposed between the plate 10 and the separator 40, having a predetermined thickness and a frame shape of which a central portion is open.

[0068] The separator spacer 80 can support an edge of the separator 40 to expand the interior space 14 of the plate 10 by the thickness of the separator spacer 80. The thickness of the separator spacer 80 is not specifically limited but can be 5 mm to 20 mm.

[0069] The liquid metal battery may further include a protective layer 90 having a shape corresponding to the open surface 11a of the plate 10 and provided on the open surface 11a of the plate 10.

[0070] The protective layer 90 may be made of a material with high chemical resistance such as rubber, resin, silicone, metal, etc.

[0071] The protective layer 90 may be porous. Accordingly, the protective layer 90 may be impregnated with the first electrolyte so that potassium ions (K + ) or sodium ions (Na + ) in the first electrolyte to the separator 40.

[0072] The protective layer 90 can prevent the separator 40 from sagging. The protective layer 90 can serve as a physical support for the separator 40.

[0073] The separator 40 may comprise a material with cation conductivity. For example, the separator 40 may comprise a perfluorosulfonic acid-based resin such as Nafion, etc. Therefore, the separator 40 may block the movement of the first electrolyte A and the second electrolyte B while allowing the movement of cations between the anode 30 and the cathode 50.

[0074] The separator 40 may comprise a material with anion conductivity. For example, the separator 40 may comprise at least one selected from the group consisting of poly(terphenylene), 1,4-diazabicyclo[2,2,2]octane poly(ethersulfone), poly(arylpiperidinium), poly(phenylene oxide)-block-poly(vinylbenzyltrimethylammonium), and combinations thereof. Accordingly, the separator 40 may block the movement of the first electrolyte A and the second electrolyte B while allowing the movement of anions between the anode 30 and the cathode 50.

[0075] The thickness of the separator 40 is not specifically limited and can be, for example, 25 µm to 250 µm.

[0076] An area of ​​the separator 40 may be larger than an area of ​​the open area 11a of the plate 10. Also, the separator 40 may cover the entire open area 11a so that leakage of the first electrolyte A can be prevented.

[0077] Fig. 6 shows a cathode spacer 60. The cathode spacer 60 may be disposed between the separator 40 and the cathode 50. The cathode spacer 60 has a frame shape with an open central portion and may support an edge of the separator 40 to thereby form a gap G between the separator 40 and the cathode 50. The cathode spacer 60 may have a thickness of 5 mm to 20 mm.

[0078] The cathode spacer 60 may comprise a material that does not react with the second electrolyte B and is chemically stable. The cathode spacer 60 may comprise, for example, polycarbonate.

[0079] The cathode spacer 60 may include a second electrolyte inlet 61 formed through a portion of the side surface of the cathode spacer 60 and configured to communicate with the gap G, and a second electrolyte outlet 62 formed through a portion of the side surface of the cathode spacer 60, spaced from the second electrolyte inlet 61 by a predetermined distance and configured to communicate with the gap G. As shown in Fig. For example, as shown in Figure 6, the second electrolyte inlet 61 may be provided in the lower side surface and the second electrolyte outlet 62 may be provided in the upper side surface. Likewise, the cathode spacer 60 may have a plurality of second electrolyte inlets 61 and a plurality of second electrolyte outlets 62.

[0080] The cathode 50 may include a noble metal catalyst loaded onto a support. The type of support is not specifically limited and may, for example, include at least one selected from the group consisting of carbon paper, carbon fiber, carbon felt, carbon black, carbon cloth, metal foam, metal thin film, and combinations thereof. The type of noble metal catalyst is not specifically limited and may, for example, include platinum (Pt).

[0081] As in Fig. As shown in Figure 7, the liquid metal battery may comprise a stack configured to stack a plurality of DC twin cells. The number of DC twin cells stacked is not specifically limited and can be adjusted accordingly depending on the desired current.

[0082] The present disclosure is characterized in that the passivation of the anode 30 is prevented by increasing the temperature of the first electrolyte A and the second electrolyte B in the liquid metal battery and the power generation rate is increased.

[0083] The pH values ​​of the first electrolyte A and the second electrolyte B can be as follows. - first electrolyte A: pH 14 or higher - second electrolyte B: pH 7 to 9

[0084] The reaction can take place sufficiently if the pH values ​​of the first electrolyte A and the second electrolyte B are within the above-mentioned ranges.

[0085] The first electrolyte A may comprise an alkali metal hydroxide. Preferably, the first electrolyte A comprises at least one alkali metal hydroxide selected from the group consisting of potassium hydroxide (KOH), sodium hydroxide (NaOH), and combinations thereof. The concentration of the first electrolyte A may be 3 M to 6 M. When the concentration of the first electrolyte A is 6 M, a saturated solution of potassium ions (K + ) or sodium ions (Na + ), whereas the ionization of the metal may not be sufficient at less than 3 M, and therefore the suitable concentration of the first electrolyte A may be 3 M to 6 M.

[0086] The temperature of the first electrolyte A may be approximately 40°C to approximately 80°C. If the temperature of the first electrolyte A is lower than approximately 40°C, it may be difficult to prevent passivation of the anode 30.

[0087] The second electrolyte B may comprise protons and bicarbonate ions. Preferably, the second electrolyte B comprises at least one element from the group consisting of potassium bicarbonate (KHCO 3 ), sodium bicarbonate (NaHCO 3 ) and combinations thereof.

[0088] Materials supplied from a second electrolyte supply unit 300, which will be described later, can be used without limitation as long as they maintain a pH of 7 to 9 in the cell (gap: G) due to the dissolution of carbon dioxide (CO 2 ) and contain protons and bicarbonate ions. Examples include potassium hydroxide, potassium carbonate, potassium bicarbonate, sodium hydroxide, sodium carbonate, and sodium bicarbonate.

[0089] The concentration of the second electrolyte B can be 0.5 M to 3 M. If the concentration of the second electrolyte B is less than 0.5 M, this may affect the reaction rate depending on an increase in pH, and a saturated solution of potassium ions (K + ) or sodium ions (Na + ) and therefore the above concentration range may be appropriate.

[0090] The temperature of the second electrolyte B can be approximately 40°C to approximately 80°C. When the temperature of the second electrolyte B falls within the above-mentioned range, the resistance in the liquid metal battery can be reduced and the occurrence of overvoltage can be prevented.

[0091] The first electrolyte A and the second electrolyte B can be preheated to temperatures within the above-mentioned numerical ranges and then added to the liquid metal battery. Preferably, the temperature of the first electrolyte A is equal to or higher than the temperature of the second electrolyte B. Since increasing the activation of the anode 30 is important for the overall reaction, the temperature of the first electrolyte A can be considered more important. Therefore, considering the overall reaction, it is preferable that the temperature of the first electrolyte A is equal to or higher than the temperature of the second electrolyte B.

[0092] The temperature of the first electrolyte A and the second electrolyte B can be increased by providing a heating element outside the liquid metal battery or by using a first heating device or means 400 and a second heating device or means 500, as described later. A preferred method for controlling the temperature of the first electrolyte A and the second electrolyte B is described below.

[0093] Fig. 8 shows a system for hydrogen production and carbon dioxide storage according to the present disclosure.

[0094] The system includes the liquid metal battery 100 described above, a first electrolyte supply unit 200 configured to supply a first electrolyte to the liquid metal battery 100, a second electrolyte supply unit 300 configured to supply a second electrolyte to the liquid metal battery 100, a first heating device 400 disposed between the liquid metal battery 100 and the first electrolyte supply unit 200 and configured to perform heat exchange between the first electrolyte and a heat source, and a second heating device 500 disposed between the liquid metal battery 100 and the second electrolyte supply unit 300 and configured to perform heat exchange between the second electrolyte and the heat source.

[0095] The temperature of the first electrolyte can be increased by transferring heat from the heat source to the first electrolyte in the first heating device 400. Likewise, the temperature of the second electrolyte can be increased by transferring heat from the heat source to the second electrolyte in the second heating device 500. The first heating device 400 and the second heating device 500 can be formed, for example, by a heat exchanger, but are not limited thereto.

[0096] The type of heat source is not specifically limited and can include, for example, exhaust gases, wastewater and the like from power plants, vehicles, landfills, etc.

[0097] The functioning of the system is described below with reference to the Fig. 1, Fig. 2 and Fig. 8 described.

[0098] The first electrolyte supply unit 200 can supply the first electrolyte A to the liquid metal battery 100 through the first electrolyte inlet 16. The first electrolyte A is heated to approximately 40°C to approximately 80°C by supplying heat from a heat source in the first heating device 400.

[0099] The first electrolyte A can be supplied through the first electrolyte inlet 16 into the interior 14 of the plate 10.

[0100] When the anode 30 comes into contact with the first electrolyte A, the anode 30 can be ionized to generate electrons. The electrons move along the support 20, the lead L, and the wire 70 to the current collector CC and are then transferred to the cathode 50.

[0101] Alkali metal ions, preferably potassium ions (K + ) or sodium ions (Na + ) generated during the ionization of the anode 30 can move through the separator 40 to the cathode 50.

[0102] The second electrolyte supply unit 300 can supply the second electrolyte B and carbon dioxide to the liquid metal battery 100 via the second electrolyte inlet 61. The second electrolyte B is heated to 40°C to 80°C by absorbing heat from the heat source in the second heating device 500. The system can further include a carbon dioxide supplier (not shown) configured to supply carbon dioxide to the second electrolyte supply unit 300. Alternatively, the second electrolyte supply unit 600 can be used to supply an electrolyte in which carbon dioxide is dissolved.

[0103] The second electrolyte B and carbon dioxide can be supplied to the cathode 50 through the second electrolyte inlet 61. The following chemical dissolution reaction of the carbon dioxide takes place at the cathode 50. CO 2 (g) + H 2 O (1) → H + (aq) + HCO 3 -(aq)

[0104] The following hydrogen production reaction then takes place at the cathode 50. 2H + (aq) + 2e - → H 2 (G)

[0105] Carbon dioxide is also stored at the cathode 50 in the form of a salt as follows. HCO 3 - (aq) + K + (aq) → KHCO 3 (G) HCO 3 - (aq) + Na + (aq) → NaHCO 3 (G)

[0106] Here H 2 and KHCO 3 (or NaHCO 3 ) together with the second electrolyte through the second electrolyte outlet 62 to the outside.

[0107] A better understanding of the present disclosure can be gained through the following test examples. These test examples are merely illustrative of the present disclosure and should not be construed as limiting the scope of the present disclosure. Test example 1

[0108] Cell performance was measured by operating a double cell DC as in Fig. 1. In addition, a liquid metal battery with a single cell, SC, structure was fabricated and its cell performance was also evaluated.

[0109] Fig. Figure 9 shows a discharge diagram of a liquid metal battery with a dual cell (DC) structure and a liquid metal battery with a single cell (SC) structure. The liquid metal battery with a dual cell (DC) structure exhibits a high cell potential at the same current, indicating that the liquid metal battery with a dual cell (DC) structure according to the present disclosure is capable of stably obtaining a higher current.

[0110] The liquid metal battery with a dual cell (DC) structure can be manufactured in a more compact cell by eliminating and reducing the size of the components in the cathode distributor, current collector, and wire compared to a liquid metal battery with multiple single cells (SC) structures. Furthermore, the use of the dual cell DC can halve the number of control factors compared to individually controlling multiple single cells (SC). Test example 2

[0111] The liquid metal battery with a double cell, DC, structure as in Fig. The liquid metal battery shown in Figure 1 was operated at different temperatures of the first electrolyte, for example, at 20 °C, 40 °C, 60 °C, and 80 °C. The zinc utilization ratio (ZUR) of the liquid metal battery is shown in Table 1 below. The ZUR value was calculated using the following equation. ZUR(zinc utilization ratio)=specific capacity of Zntheoretical capacity of Zn [Table 1] Temperatur 20 °C 40 °C 60 °C 80 °C ZUR [%] 25,56 51,89 83,60 87,50

[0112] When the temperature of the first electrolyte is 20 °C, the ZUR value is about 25%, while when the temperature of the first electrolyte is 80 °C, it increases sharply and is about 87%.

[0113] Fig. Figure 10 shows a discharge diagram as a function of the current density of the liquid metal battery at different temperatures of the first electrolyte. Fig. Figure 11 shows a discharge diagram versus time of the liquid metal battery at different temperatures of the first electrolyte. The higher the electrolyte temperature, the better both the operating performance and the operating time. Test example 3

[0114] The liquid metal battery with a double cell, DC, structure, as in Fig. 1, was operated at different temperatures of the second electrolyte, for example 20 °C, 40 °C, 60 °C and 80 °C.

[0115] Fig. Figure 12 shows the evaluation results of the liquid metal battery at different second electrolyte temperatures. The higher the second electrolyte temperature, the lower the electrode overvoltage. Specifically, when the second electrolyte temperature was increased from 20°C to 40°C or from 40°C to 80°C, the overvoltage was approximately 0.05 V, confirming a lower battery resistance. Test example 4

[0116] The liquid metal battery with the Fig. The double cell, DC, structure shown in Figure 1 was operated under the following conditions. Condition 1: first electrolyte temperature 20 °C, second electrolyte temperature 20 °C Condition 2: first electrolyte temperature 80 °C, second electrolyte temperature 20 °C Condition 3: first electrolyte temperature 80 °C, second electrolyte temperature 80 °C

[0117] Fig. Figure 13 shows a discharge diagram of the liquid metal battery operated under conditions 1 to 3. Conditions 2 and 3 showed similar cell performance. It can be seen that the temperature of the first electrolyte, rather than the temperature of the second electrolyte, has a greater impact on the performance changes as the electrolyte temperature increases.

[0118] As is apparent from the above description, according to the present disclosure, a liquid metal battery with improved power generation amount and power generation rate can be obtained.

[0119] According to the present disclosure, a liquid metal battery can be obtained that prevents the anode from being passivated.

[0120] Since the test examples and embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited to the test examples and embodiments described above, and various modifications and improvements made by a person skilled in the art using the basic concept of the present disclosure defined in the following claims also fall within the scope of the present disclosure.

Claims

[1] Liquid metal battery, comprising: a double cell, comprising: a pair of single cells, each of the single cells having: an anode, a cathode, a separator arranged between the anode and the cathode, and a cathode spacer disposed between the separator and the cathode and configured to form a gap between the separator and the cathode; and a current collector arranged between the pair of individual cells such that cathodes of the individual cells face each other across the current collector. [2] A liquid metal battery according to claim 1, wherein: each of the individual cells further comprises a plate in sheet form having a predetermined thickness, which plate has a first main surface and a second main surface facing the first main surface, which second main surface is arranged on an outer surface of the individual cell and has an interior space open to the first main surface, the anode is accommodated in the interior, and the separator is stacked on the first main surface to cover an open area of ​​the interior. [3] A liquid metal battery according to claim 2, wherein the plate comprises: a first electrolyte inlet formed in a portion of a side surface and configured to communicate with the interior space; and a first electrolyte outlet formed at a position spaced from the first electrolyte inlet by a predetermined distance and configured to communicate with the interior space. [4] A liquid metal battery according to claim 2, wherein: the anode is in the form of a pellet, each of the individual cells further comprises a support provided obliquely in the interior space and having a plurality of through holes, the anode is accommodated between an inner surface of the plate and the support, and a diameter of the through holes is smaller than a diameter of the anode. [5] A liquid metal battery according to claim 2, wherein: the anode is in the form of a plate, and each of the individual cells further comprises a pressing member received in the interior space and provided between an inner surface of the plate and the anode for exerting a pressing force to move the anode toward the separator. [6] The liquid metal battery of claim 1, wherein the anode comprises at least one of the group consisting of lithium (Li), sodium (Na), magnesium (Mg), zinc (Zn), aluminum (Al), and a combination thereof. [7] The liquid metal battery of claim 1, further comprising a wire configured to electrically connect the anode and the current collector. [8] A liquid metal battery according to claim 1, wherein the cathode comprises a noble metal catalyst loaded on a carrier. [9] The liquid metal battery according to claim 2, further comprising a separator spacer disposed between the plate and the separator, having a predetermined thickness, and having a frame shape of which a central portion is open, the separator spacer supporting an edge of the separator to expand the interior space of the plate by a thickness of the separator spacer. [10] The liquid metal battery according to claim 2, further comprising a protective layer having a shape corresponding to the open surface of the plate, provided on the open surface of the plate, and being porous. [11] The liquid metal battery according to claim 1, wherein the separator comprises a material having cation conductivity or a material having anion conductivity. [12] A liquid metal battery according to claim 1, wherein: the cathode spacer has a frame shape, a central portion of which is open, and supports an edge of the separator to form the gap, and the cathode spacer has a second electrolyte inlet formed in a portion of a side surface of the cathode spacer and configured to communicate with the gap, and a second electrolyte outlet formed in a portion of a side surface of the cathode spacer spaced from the second electrolyte inlet by a predetermined distance and configured to communicate with the gap. [13] Liquid metal battery according to claim 2, further comprising: a first electrolyte accommodated in the interior of the plate; and a second electrolyte accommodated in the gap. [14] A liquid metal battery according to claim 13, wherein the first electrolyte comprises an alkali metal hydride. [15] A liquid metal battery according to claim 13, wherein the second electrolyte comprises protons and bicarbonate ions. [16] The liquid metal battery of claim 13, wherein the temperature of the first electrolyte is about 40°C to about 80°C or the temperature of the second electrolyte is about 40°C to about 80°C. [17] The liquid metal battery according to claim 13, wherein the temperature of the first electrolyte is equal to or higher than the temperature of the second electrolyte. [18] The liquid metal battery of claim 1, comprising a stack configured to stack a plurality of double cells. [19] System for hydrogen production and carbon dioxide storage, comprising: the liquid metal battery according to claim 1; a first electrolyte supply unit configured to supply a first electrolyte to the liquid metal battery; and a second electrolyte supply unit configured to supply a second electrolyte to the liquid metal battery. [20] The hydrogen generation and carbon dioxide storage system according to claim 19, further comprising a first heating device disposed between the liquid metal battery and the first electrolyte supply unit, and a second heating device disposed between the liquid metal battery and the second electrolyte supply unit.

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