KR20210137827A - Neutral electrolyte based metal air battery comprising sparked graphene oxide cathode - Google Patents

Abstract

According to an embodiment of the present invention, a metal-air battery includes: an anode comprising a metallic material; a cathode including sparked graphene oxide (sGO) in which a plurality of pores having different diameters are formed by thermal shock applied to the graphene oxide (GO); and a separator disposed between the anode and the cathode and comprising a predetermined liquid electrolyte. In the cathode, different volumes of liquid electrolytes are introduced into the plurality of pores according to the diameters of the plurality of pores, and thus a three-phase interface composed of oxygen, liquid electrolytes and sparked graphene oxide (sGO) can be formed. The present invention provides the metal-air battery with a reduced risk of explosion by using a stable neutral electrolyte.

Description

Neutral Electrolyte-Based Metal-Air Battery Containing Sparked Graphene Oxide Reduction Electrode {NEUTRAL ELECTROLYTE BASED METAL AIR BATTERY COMPRISING SPARKED GRAPHENE OXIDE CATHODE}

Embodiments relate to a neutral electrolyte-based metal-air battery including a sparked graphene oxide anode and a method for manufacturing the same.

In recent years, as the commercialization of electric vehicles is visualized due to technological development in the battery field, the market for large-capacity batteries to be used therein is growing significantly.

Currently, the absolute majority of commercialized electric vehicles use lithium-ion batteries, which are widely used in other electronic devices, as an energy source. However, due to the theoretical energy density limit of lithium-ion batteries, there is a problem in that they have no choice but to have a shorter mileage compared to conventional internal combustion engine-based vehicles.

To overcome this, metal-air batteries have emerged as a candidate to replace lithium-ion batteries since the 2000s.

A typical example of a metal-air battery is an aluminum-air battery. An aluminum-air battery is a metal-air battery that operates by oxidizing aluminum at the anode and oxygen in the atmosphere, which is introduced through the cathode of the battery, reacts with water present in the electrolyte. Aluminum-air batteries use aluminum as the active material for the anode and oxygen in the air as the reactant for the cathode.

The oxygen reduction reaction that occurs at the reduction electrode of a metal-air battery is a reaction that occurs when three phases of gas (oxygen), liquid (electrolyte), and solid (electrode and electron) meet. can be decided.

In addition, the reaction rate may vary depending on the type of electrolyte. Electrolytes used in metal-air batteries include neutral sodium chloride and basic potassium hydroxide aqueous solution. Among them, the basic electrolyte has a relatively fast reaction rate of the oxygen reduction reaction, but there is a problem in that aluminum, which is a metal included in the oxide electrode, is self-corroded.

The use of a neutral electrolyte has the advantage of excellent safety of the metal-air battery, but has a problem in that the reaction rate of the oxygen reduction reaction is relatively slow. In addition, in the case of using a neutral electrolyte, unlike the case of using an acidic or basic electrolyte, a catalyst capable of accelerating the oxygen reduction reaction is rare, so there is a limitation in improving the reaction rate.

Therefore, research on a method for improving the overall output of the battery while ensuring the stability of the metal-air battery by using a neutral electrolyte is in progress.

The problem to be solved through the embodiments is that a three-phase interface composed of oxygen, a liquid electrolyte, and sparked graphene oxide (sGO) is formed by introducing a liquid electrolyte of different volumes into a plurality of pores having different diameters into the pores. To provide a metal-air battery.

The problems to be solved through the embodiments are not limited to the above-described problems, and the problems not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the present specification and the accompanying drawings. will be.

As a technical means for achieving the above-described technical problem, a metal-air battery according to an embodiment, an oxide electrode including a metal material, a plurality of different diameters by thermal shock applied to graphene oxide (GO) A cathode comprising sparked graphene oxide (sGO) in which pores of A three-phase interface composed of oxygen, a liquid electrolyte, and sparked graphene oxide (sGO) may be formed by introducing a liquid electrolyte of different volumes according to the diameter into the plurality of pores.

In addition, the sparked graphene oxide (sGO) is locally applied to a region of the graphene oxide (GO) by thermal shock, so that the pores of the first region formed with a first diameter, and a second diameter larger than the first diameter The second region to be formed may include pores.

In addition, the liquid electrolyte is preferentially introduced into the pores of the first region over the pores of the second region due to capillary action, the liquid electrolyte flows into the pores of the first region by a first ratio, and the liquid electrolyte is supplied into the pores of the second region A second ratio smaller than the first ratio may be introduced.

In addition, the volume of the electrolyte absorbed into the separator may be 25.71 μL/mg to 45 μL/mg relative to the weight of the sparked graphene oxide (sGO).

In addition, the volume ratio of the liquid electrolyte filled in the plurality of pores to the volume of the plurality of pores may be 70% to 80%.

In addition, the thermal shock may be to apply heat locally to a region of graphene oxide (GO) in the first temperature range by liquid sodium.

In addition, the thermal shock may be to apply heat locally to a region of graphene oxide (GO) in the second temperature range by an iron.

In addition, the electrolyte may include at least one selected from the neutral electrolyte KCL, NaCL, or a combination thereof.

In addition, the concentration of the electrolyte may be 5 wt% or more and 20 wt% or less.

In addition, it may further include a first electrode including silver (Ag) and attached to the anode and a second electrode including silver (Ag) and attached to the cathode.

The metal-air battery according to another embodiment includes a plurality of metal-air batteries by using the metal-air battery according to the above-described embodiment as one unit cell, and the plurality of metal-air batteries includes a first electrode and the second electrode. through which they can be electrically connected to each other.

The metal-air battery according to the embodiments allows electrolytes of different volumes to be introduced into a plurality of pores having different diameters included in the sparked graphene oxide anode to maximize the area of the three-phase interface where the oxygen reduction reaction occurs. can Accordingly, by improving the oxygen reduction reaction rate of the cathode, it is possible to provide a metal-air battery with increased energy density, excellent economic feasibility, and reduced risk of explosion by using a stable neutral electrolyte.

The effects of the embodiments are not limited to the above-described effects, and the effects not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention pertains from the present specification and accompanying drawings.

1 is a schematic diagram of a metal-air battery according to an embodiment.
2 is a schematic diagram showing a spark reaction process for generating sparked graphene oxide according to an embodiment.
3 is a view comparing a state in which a liquid electrolyte is introduced into graphene oxide according to a comparative example and a state in which a liquid electrolyte is introduced into sparked graphene oxide according to an embodiment.
4 shows (a) a three-phase interface formed on graphene oxide into which a liquid electrolyte is introduced according to a comparative example, and (b) a three-phase interface formed on sparked graphene oxide into which a liquid electrolyte according to an embodiment is introduced. It is a comparative diagram.
5 is a schematic diagram and a scanning electron microscope (SEM) image of graphene oxide, sparked graphene oxide, and sparked graphene oxide in which a liquid electrolyte is introduced into the pores.
6 is (a) X-ray diffraction analysis (XRD), (b) X-ray photoelectron spectroscopy (XPS), (c) Raman and (d) FT-IR analysis data of graphene oxide and sparked graphene oxide. .
7 is BET analysis data of sparked graphene oxide and graphene oxide reduced with hydrazine vapor (hGO).
8 is a graph showing the relationship between the density of the three-phase interface and the volume of the liquid electrolyte filled in the pores.
9 is a graph relating to the output according to the liquid electrolyte volume of the metal-air battery according to an embodiment.
10 is (a) a polarization curve, (b) a current-output curve, and (c) a discharge curve of a metal-air battery and a metal-air battery including a thin film of graphene oxide (hGO) reduced with hydrazine vapor according to an embodiment; is a graph about
11 is a graph of a discharge curve according to a discharge current of a metal-air battery according to an embodiment.
12 is a graph showing a polarization curve when a plurality of metal-air batteries according to an embodiment are connected in series or in parallel.
13 is a view showing whether a metal-air battery can be operated after damage to a series-connected metal-air battery according to an embodiment;
14 is a diagram relating to an experiment on whether a metal-air battery according to an embodiment is harmless to the human body.

Phrases such as “in some embodiments” or “in one embodiment” appearing in various places in this specification are not necessarily all referring to the same embodiment.

The terms used in the embodiments are selected as currently widely used general terms as possible while considering the functions in the embodiments, but these are the intentions or precedents of those skilled in the art to which the embodiments belong, the emergence of new technologies, etc. may vary depending on In addition, in a specific case, there is a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the relevant part. Therefore, terms used in the embodiments should be defined based on the meaning of the terms and the contents throughout the embodiments, rather than the simple names of terms.

Since the embodiments may have various changes and may have various forms, some embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the embodiments to a specific disclosure form, and it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the embodiments. Terms used in the specification are used only for description of the embodiments, and are not intended to limit the embodiments.

Unless otherwise defined, terms used in the embodiments have the same meanings as commonly understood by those of ordinary skill in the art to which the embodiments belong. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in the embodiments, interpreted in an ideal or excessively formal meaning shouldn't be

1 is a schematic diagram of a metal-air battery 100 according to an embodiment.

Referring to FIG. 1 , in the metal-air battery 100 , a plurality of pores 171 having different diameters are formed by thermal shock applied to an oxide electrode 110 including a metal material and graphene oxide (GO). It is disposed between the anode 120 and the anode 110 and the cathode 120 including the sparked graphene oxide (sGO, 170) formed and a predetermined liquid electrolyte 180 (electrolyte). It may include an absorbed separator (130).

The material of the oxide electrode 110 may include, without limitation, various materials used in the field of metal-air battery technology. According to one embodiment, the oxide electrode 110 is an aluminum thin film, and the metal-air battery 100 is aluminum. It is an air battery.

The first electrode 140 includes silver (Ag) paste, and is attached to the anode 110 through the silver paste, and the second electrode 150 is attached to the cathode 120 through the silver paste. can be

The sealing unit 160 is a plastic pack or pouch cell, and sealing the oxide electrode 110 , the reducing electrode 120 , the separator 130 and the electrodes 140 and 150 , but the electrodes 140 , 150 , by protruding out of the sealing unit 160 , may supply power to an external electronic device.

The oxide electrode 110 , the reduction electrode 120 , the separator 130 , and the electrodes 140 , 150 may be used as cells constituting the metal-air battery 100 . The metal-air battery 100 may be configured by connecting a plurality of cells in series or in parallel. At this time, each anode 110 and each cathode 120 are connected in series or in parallel through a conductive textile and silver paste.

The cathode 120 may include sparked graphene oxide 170 . Sparked graphene oxide 170 may be generated by locally applying thermal shock to one region of graphene oxide (GO). According to an embodiment, the cathode 120 may include graphene oxide in another region to which thermal shock is not applied.

Thermal shock may be a spark reaction process in which heat is locally applied to a region of graphene oxide by a heating means. For example, the thermal shock may be the application of heat to the first temperature range by liquid sodium. At this time, the first temperature range may be 200 ℃ to 350 ℃. In addition, the thermal shock may be applying heat to the second temperature range by an iron. In this case, the second temperature range may be 400°C to 450°C. However, the heating means and the temperature range are not limited to the above.

2 is a schematic diagram showing the spark reaction process.

Figure 2 (a) is graphene oxide, it can be seen that oxygen and hydrogen functional groups are disposed between the graphene layers. Thereafter, as shown in FIGS. 2(b) and 2(c), when a thermal shock is applied to graphene oxide, the interlayer spacing and the diameter of pores 171 of graphene oxide increase, and oxygen functional groups As they leave, reduction can be facilitated.

Ingredients (%) Graphene Oxide (GO) Sparked graphene oxide (sGO, 170) C (%) 55.82 81.33 O(%) 44.18 18.67 Ratio (C/O) 1.263 4.356

Table 1 compares the component ratio of graphene oxide and the sparked graphene oxide 170 after transforming graphene oxide into sparked graphene oxide 170 through a spark reaction. It can be seen that the ratio of carbon to oxygen of the sparked graphene oxide 170 becomes 4.356, so that the oxygen functional groups are separated. Accordingly, the electrical conductivity of the sparked graphene oxide 170 may also increase.

3 shows a state in which the liquid electrolyte 180 is introduced into the graphene oxide 200 according to a comparative example, and a state in which the liquid electrolyte 180 is introduced into the sparked graphene oxide 170 according to an embodiment. It is a comparative drawing.

Referring to FIG. 3A , graphene oxide 200 according to a comparative example may include pores 271 formed between stacked planes. When the difference in diameter of each of the pores 271 is relatively small, the liquid electrolyte 180 may be introduced into each of the pores 271 by a similar volume. Accordingly, the liquid electrolyte 180 introduced into each of the pores 271 forms a uniform distribution.

Referring to FIG. 3B , the sparked graphene oxide 170 may include a plurality of pores 171 having different diameters between the stacked planes. Specifically, since the thermal shock is locally applied to a portion of the graphene oxide, the interlayer spacing and the diameter of the pores 171 may be non-uniformly expanded, so that the diameters of the plurality of pores 171 may be different from each other.

The pores 171 may accommodate air containing oxygen. Also, the liquid electrolyte 180 may be introduced into the pores 171 . The liquid electrolyte 180 and gas, oxygen, may be simultaneously introduced into the pores 171 .

Liquid electrolyte 180 having different volumes may be introduced into the plurality of pores 171 having different diameters, respectively. At this time, the liquid electrolyte 180 may be preferentially introduced into the small-diameter pores 174 than the large-diameter pores 172 due to the capillary phenomenon.

4 shows (a) a three-phase interface formed in the graphene oxide 200 into which the liquid electrolyte 180 according to a comparative example is introduced, and (b) a sparked liquid electrolyte 180 according to an embodiment. It is a schematic diagram comparing the three-phase interface formed on the graphene oxide 170.

The three-phase interface means an interface composed of oxygen as a gas, a liquid electrolyte 180 as a liquid, and sparked graphene oxide 170 as a solid. The three-phase interface can be said to be a place where oxygen, the liquid electrolyte 180, and the sparked graphene oxide 170 meet at the reducing electrode 120 of the metal-air battery 100 to cause an oxygen reduction reaction. As the area of the three-phase interface increases, the reaction rate of the oxygen reduction reaction may increase, thereby increasing the output of the metal-air battery 100 .

Referring to FIG. 4A , when the diameters of the pores 271 arranged side by side are the same, the liquid electrolyte 180 may be introduced into each of the pores 271 by the same volume. Accordingly, a region 271b into which the liquid electrolyte 180 is introduced may be formed in the pores 271 . In addition, oxygen is introduced into each pore 271 to form a region 271a into which oxygen is introduced.

The three-phase interface may be formed along the circumference 271c at the boundary between the region 271b in which the liquid electrolyte 180 is introduced into the pores 271 and the region 271a in which oxygen is introduced into the pores 271 .

Referring to FIG. 4B , the sparked graphene oxide 170 may include pores 171 having different diameters. The sparked graphene oxide 170 may include small-diameter pores 174 and large-diameter pores 172 adjacent thereto. When the diameters of the pores 172 and 174 are different, the liquid electrolyte 180 may be introduced by a different volume into each of the pores 172 and 174 due to capillary action.

The liquid electrolyte 180 and oxygen are introduced into the pores 174 having a small diameter to form a region 174b into which the liquid electrolyte 180 is introduced and a region 174a into which oxygen is introduced. The large-diameter pores 172 have different volumes of the liquid electrolyte 180 and oxygen from those of the small-diameter pores 174, so that the liquid electrolyte 180 is introduced into the region 172b and oxygen is introduced into the region 172a. ) can be formed.

Between the adjacent pores 172 and 174, the side surface 174d of the region 174b in which the liquid electrolyte 180 is introduced into the small-diameter pores 174 is the region 172a in which the oxygen of the large-diameter pores 172 is introduced. ) is easily exposed to oxygen. Accordingly, a three-phase interface may be formed along the side surface 174d of the pores 174 having a small diameter. In addition, the three-phase interface may be formed along the circumferences 172c and 174c at the boundary between the regions 172b and 174b into which the liquid electrolyte 180 is introduced and the regions 172a and 174a into which oxygen is introduced.

That is, in the sparked graphene oxide 170, the three-phase interface is the perimeter of the boundary between the regions 172b and 174b into which the liquid electrolyte 180 is introduced and the regions 172a and 174a into which oxygen is introduced. It may be formed along the side surface 174d of the small-diameter pore 174 .

Accordingly, the sparked graphene oxide 170 according to an embodiment includes pores 171 of different diameters, so that a three-phase interface of a larger area is formed than the graphene oxide 200 according to a comparative example. can

5 is a schematic diagram and a scanning electron microscope (SEM) image of graphene oxide, sparked graphene oxide 170 and sparked graphene oxide 170 in which liquid electrolyte 180 is introduced into pores 171 .

Referring to FIGS. 5A and 5B , it can be seen that the interlayer spacing of the sparked graphene oxide 170 is increased compared to that of the graphene oxide, and a plurality of pores 171 of different diameters are formed. . Also, referring to FIG. 5C , it can be seen that the liquid electrolyte 180 is introduced into some of the plurality of pores 171 .

6 shows (a) X-ray diffraction analysis (XRD), (b) X-ray photoelectron spectroscopy (XPS), (c) Raman, and (d) FT-IR of graphene oxide and sparked graphene oxide 170 analysis data.

Referring to Figure 6 (a), it can be confirmed that the interlayer gap included in the graphene oxide and the sparked graphene oxide 170. It can be seen that the interlayer spacing of the graphene oxide 170 sparked by thermal shock is 0.38 nm.

Referring to FIG. 6(b) , the binding energy of the graphene oxide and the sparked graphene oxide 170 can be confirmed. It can be seen that the carbon-oxygen bond decreases and the carbon-carbon bond increases after the spark reaction. Accordingly, the electrical conductivity of the sparked graphene oxide 170 can be expected to be superior to the electrical conductivity of the graphene oxide.

In addition, referring to FIG. 6( c ), it can be confirmed that the G peak of graphene oxide shifted to the left after the spark reaction, which can be interpreted as a phenomenon that occurs when graphene oxide is reduced and the sp2 graphitic domain is restored. .

In addition, referring to FIG. 6( d ), functional groups of graphene oxide and sparked graphene oxide 170 can be confirmed. As the peak corresponding to the -OH group disappears after the spark reaction, it can be seen that the -OH group and water molecules are blown away by thermal shock. it can be seen that

7 is BET analysis data of sparked graphene oxide 170 and graphene oxide reduced with hydrazine vapor (hGO).

Referring to FIG. 7( a ), the distribution according to the diameter of the pores 171 of graphene oxide (hGO) reduced with hydrazine vapor used as a comparison group can be confirmed. It can be seen that the pores 171 having a diameter of 0.7 nm are most distributed in hGO, and the diameter of the pores 171 is distributed over 30 nm.

Referring to Figure 7 (b), it can be confirmed the distribution according to the diameter of the pores 171 of the sparked graphene oxide 170. It can be seen that the pores 171 have various diameters from several nm to several tens of nm and are distributed, and the distribution of the pores 171 of various sizes can play an important role in the formation of the three-phase interface as described above. have.

The distribution along the diameter of the pores 171 of the sparked graphene oxide 170 is 5 nm to 15 nm, 15 nm to 25 nm, 25 nm to 35 nm, 35 nm to 45 nm, 45 nm to 55 nm, 55 nm to 65 nm, 65 nm to based on the BET data. It can be divided into 7 compartments of 75 nm. The pores 171 having a diameter of 5 nm to 15 nm occupy the largest proportion of the distribution of the entire pores 171 .

The pores 171 of the first region of the sparked graphene oxide 170 may have a first diameter, and the pores 171 of the second region may have a second diameter greater than the first diameter. For example, the first diameter may be between 5 nm and 15 nm, and the second diameter may include a diameter greater than 15 nm. Also, the first and second regions may not be continuously formed.

The liquid electrolyte 180 may flow into the pores 171 of the first region by a first ratio, and the liquid electrolyte 180 may flow into the pores 171 of the second region by a second ratio smaller than the first ratio. . For example, the first ratio may be 90% to 100% of the state in which the liquid electrolyte 180 is introduced into the entire pores 171 , but is not limited thereto and may mean a ratio greater than the second ratio.

In the method of introducing the liquid electrolyte 180 into the pores 171 , the liquid electrolyte 180 is immersed in the separator 130 , and the liquid electrolyte 180 immersed in the cathode 120 through the separator 130 moves. There is a method to do so, but it is not limited by the above-mentioned bar.

8 is a graph showing the relationship between the density of the three-phase interface and the volume of the liquid electrolyte 180 filled in the pores 171 .

The measurement of the liquid electrolyte 180 introduced into the pores 171 may be measured through the change in weight of the sparked graphene oxide 170 immersed in the liquid electrolyte 180 .

When the weight of the sparked graphene oxide 170 is measured before being immersed in the liquid electrolyte 180, and the increased weight change is measured by immersion in the liquid electrolyte 180, the liquid introduced into the sparked graphene oxide 170 is measured. The volume of the electrolyte 180 can be confirmed. The total volume of the pores 171 of the sparked graphene oxide 170 can be confirmed by measuring the weight change after immersing the sparked graphene oxide 170 in a sufficiently large amount of the liquid electrolyte 180 . However, measuring the volume of the liquid electrolyte 180 immersed in the sparked graphene oxide 170 is not limited by the above description and may be made in various ways.

Referring to FIG. 8 , the relationship between the volume ratio of the liquid electrolyte 180 introduced into the pores 171 and the density of the three-phase interface can be confirmed. The density of the three-phase interface may be proportional to the area of the three-phase interface.

The volume ratio of the liquid electrolyte 180 introduced into the pores 171 means the volume of the liquid electrolyte 180 introduced into the pores 171 compared to the volume of all pores 171 .

As the volume of the liquid electrolyte 180 increases, the volume ratio of the liquid electrolyte 180 introduced into the pores 171 increases. As the volume ratio of the liquid electrolyte 180 introduced into the pores 171 increases, the density of the three-phase interface may increase. In the section where the volume ratio of the liquid electrolyte 180 introduced into the pores 171 is 70% to 80%, it can be seen that the density of the three-phase interface increases and then decreases.

Referring back to FIG. 4 , when the inflow into the pores 171 of the liquid electrolyte 180 starts, a three-phase interface may be formed as shown in FIG. 4(b). When the inflow of the liquid electrolyte 180 into the small-diameter pores 174 is completed due to the capillary phenomenon, the inflow into the relatively large-diameter pores 172 may be active. Accordingly, the area corresponding to the side surface 174d of the small-diameter pore 174 is reduced, so that a three-phase interface is formed as shown in FIG. 4(a), so that the three-phase interface can be reduced.

That is, the critical point at which the three-phase interface increases and then decreases may be the point at which the introduction of the liquid electrolyte 180 into the small-diameter pores 174 is completed. The section in which the volume ratio of the liquid electrolyte 180 introduced into the pores 171 is 70% to 80% may be a section in which the introduction of the liquid electrolyte 180 into the pores 174 having a small diameter is completed. For example, it may be a point at which the introduction of the liquid electrolyte 180 into the pores 171 having a diameter of 5 nm to 15 nm is completed.

In summary, the condition for high output of the metal-air battery 100 is that the volume ratio of the liquid electrolyte 180 filled in the plurality of pores 171 to the total volume of the plurality of pores 171 is 70% to 80% It can be confirmed that The liquid electrolyte 180 flowing into the pores 171 may include at least one selected from neutral electrolytes KCL, NaCL, or a combination thereof, but is not limited thereto.

In addition, the concentration of the liquid electrolyte 180 may be 5 wt% or more and 20 wt% or less, but is not limited thereto.

Referring back to FIG. 8(b), in the graph of FIG. 8(b), the volume ratio of the liquid electrolyte 180 introduced into the pores 171 according to the volume of the liquid electrolyte 180 absorbed in the separator 130 and 3 The density of the phase interface can be confirmed.

9 is a graph regarding the output according to the volume of the liquid electrolyte 180 of the metal-air battery 100 according to an embodiment.

Referring to FIG. 9 , the output of the metal-air battery 100 according to the volume of the liquid electrolyte 180 absorbed in the separator 130 may be compared. When the volume of the liquid electrolyte 180 absorbed by the separator 130 is 180 μL to 315 μL, preferably 270 μL, it can be confirmed that the output of the metal-air battery 100 is excellently secured.

Therefore, it can be confirmed that the volume of the liquid electrolyte 180, which ensures excellent output of the metal-air battery 100 while ensuring the area of the three-phase interface, is 180 μL to 315 μL.

Since the weight of the sparked graphene oxide 170 used for measurement is 7 mg, the volume of the liquid electrolyte 180 absorbed in the separator 130 is 25.71 μL/mg to 45 μL compared to the weight of the sparked graphene oxide 170 In the case of /mg, it is possible to secure the metal-air battery 100 with excellent output.

In addition, when the volume of the liquid electrolyte 180 is 270 μL, it can be confirmed that the measured output is the best. This is a case in which the volume ratio of the liquid electrolyte 180 absorbed in the pores 171 to the volume of the entire pores 171 is 72.55%, and is included in the range of 70% to 80% of the volume ratio described above.

10 shows (a) a polarization curve, (b) current- It is a graph relating to the output curve and (c) the discharge curve.

Referring to FIGS. 10 ( a ) and 10 ( b ), the metal-air battery including the sparked graphene oxide 170 thin film is significantly higher than the metal-air battery including the graphene oxide thin film reduced with hydrazine vapor. Short-circuit current, maximum output, and specific capacity are shown. Graphene oxide reduced with hydrazine vapor has a pore 171 structure similar to that of the sparked graphene oxide 170, but is a hydrophobic material, and does not sufficiently absorb the liquid electrolyte 180, and thus exhibits inferior performance.

11 is a graph of a discharge curve according to a discharge current of the metal-air battery 100 according to an embodiment.

Referring to FIG. 11 , FIG. 11 is a graph of a discharge curve according to a discharge current of a metal-air battery 100 including a sparked graphene oxide 170 thin film. When aluminum is included in the oxide electrode 110 of the metal-air battery 100, an oxidation reaction of aluminum as a main reaction and a corrosion reaction of aluminum as a side reaction occur competitively. Therefore, it can be seen that the higher the discharge current of the metal-air battery 100 is, the larger the capacity is. The metal-air battery 100 exhibited a maximum capacity of 2392 mAh/g at a discharge current of 160 μA/cm 2 .

12 is a graph relating to a polarization curve when a plurality of metal-air batteries 100 according to an embodiment are connected in series or in parallel.

Referring to FIG. 12( a ), when two or four metal-air batteries 100 are connected in series, it can be seen that the open circuit voltage is increased by about 2 times and 4 times. Referring to FIG. 12( b ), when two or four metal-air batteries 100 are connected in parallel, the short-circuit current is increased by about 2 times and 4 times. Accordingly, the metal-air battery 100 according to an embodiment may be used by connecting a plurality of metal-air batteries 100 in series or in parallel as desired.

13 is a view showing whether a metal-air battery can be operated after damage to a series-connected metal-air battery according to an embodiment.

Referring to FIG. 13 , after the metal-air battery 100 including the sparked graphene oxide 170 is connected in series, the metal-air battery 100 is in a damaged state (eg, pierced with a needle). It can be seen that is working normally. In addition, when four metal-air batteries 100 are connected in series, 19 parallel-connected LEDs can be turned on, and it can be confirmed that the LEDs are turned on without change even when the metal-air battery 100 is pierced with a needle. Accordingly, it can be seen that the output of the metal-air battery 100 is stably maintained even in a state in which the metal-air battery 100 is damaged.

14 is a diagram related to an experiment on whether the metal-air battery 100 according to an embodiment is harmless to the human body.

Referring to FIG. 14 , it is a photograph confirming that no harm is done to the human body when the perforated metal-air battery 100 is attached to the human body for 3 days and then removed. Since the metal-air battery 100 according to an embodiment uses a neutral electrolyte, it can be confirmed that it is harmless to the human body as compared to the metal-air battery according to a comparative example using an acidic or basic electrolyte.

On the other hand, those of ordinary skill in the technical field related to the embodiments will understand that it may be implemented in a modified form within a range that does not deviate from the essential characteristics of the above description. Therefore, the disclosed methods are to be considered in an illustrative rather than a restrictive sense. The scope of the invention is indicated in the claims rather than in the foregoing description, and all differences within the scope equivalent thereto should be construed as being included in the invention.

100: metal air battery
110: oxide electrode
120: cathode
130: separator
140: first electrode
150: second electrode
160: seal
170: sparked graphene oxide
171: Qigong
172: large diameter pores
174: small diameter pores
180: liquid electrolyte
200: graphene oxide
271: Qigong

Claims (11)

an oxide electrode comprising a metal material;
a cathode including sparked graphene oxide (sGO) in which a plurality of pores having different diameters are formed by thermal shock applied to graphene oxide (GO); and
a separator disposed between the anode and the cathode and comprising a predetermined liquid electrolyte; including,
In the cathode, the liquid electrolyte of different volumes according to the diameter of the plurality of pores is introduced into the plurality of pores, whereby a three-phase interface composed of oxygen, liquid electrolyte and sparked graphene oxide (sGO) is formed, metal air battery. According to claim 1,
The sparked graphene oxide (sGO) is
The thermal shock is locally applied to a region of the graphene oxide (GO),
pores in the first region formed with a first diameter;
A metal-air battery comprising a; pores in the second region formed with a second diameter greater than the first diameter. 3. The method of claim 2,
The liquid electrolyte is preferentially introduced into the pores of the first region than the pores of the second region due to capillary action,
The liquid electrolyte is introduced into the pores of the first region by a first ratio,
The liquid electrolyte is introduced into the pores of the second region by a second ratio smaller than the first ratio, a metal-air battery. According to claim 1,
The volume of the liquid electrolyte absorbed into the separator is 25.71 μL/mg to 45 μL/mg based on the weight of the sparked graphene oxide (sGO), a metal-air battery. According to claim 1,
A volume ratio of the liquid electrolyte introduced into the plurality of pores relative to the volume of the plurality of pores is 70% to 80%, a metal-air battery. 3. The method of claim 2,
The thermal shock is to apply heat locally to a region of the graphene oxide (GO) in a first temperature range by liquid sodium. 3. The method of claim 2,
The thermal shock is to apply heat locally to a region of the graphene oxide (GO) in a second temperature range by an iron, a metal-air battery. According to claim 1,
The liquid electrolyte comprises at least one selected from the neutral electrolyte KCL, NaCL, or a combination thereof, a metal-air battery. According to claim 1,
The concentration of the liquid electrolyte is 5 wt% or more and 20 wt% or less, a metal-air battery. According to claim 1,
a first electrode comprising silver (Ag) and attached to the anode; and
Containing silver (Ag), the second electrode is attached to the cathode; further comprising a metal-air battery. 11. The method of claim 10,
A plurality of metal-air batteries are included by using the metal-air battery as one unit battery,
The plurality of metal-air batteries are electrically connected to each other through the first electrode and the second electrode.

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