KR101540786B1 - Complex catalyst for zinc air battery, method of preparing the same, air electrode for zinc air battery and zinc air battery including the same - Google Patents

Abstract

The present invention relates to a composite catalyst for a zinc air cell, a method for producing the same, a cathode for a zinc air cell and a zinc air cell containing the same, which comprises a carbon black-carbonized gelatin compound, A composite catalyst for an air cell is provided.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite catalyst for a zinc-air battery, a method for producing the composite catalyst, a cathode for a zinc air battery and a zinc air battery including the same,

A composite catalyst for a zinc air cell, a method for producing the same, an air electrode for a zinc air battery and a zinc air cell including the same.

A metal air cell is a cell that operates by using oxygen as an energy source in the air at the anode. It is a battery that plays an important role in developing an electric vehicle, which has a higher output and energy density than a conventional primary battery or a typical secondary battery, a lithium ion battery, and is the ultimate goal of the battery field.

The types of metal air cells include lithium and zinc air cells depending on the metal.

In the case of lithium metal, it is dangerous to react with water because it is explosive and it is difficult to control the moisture in the manufacturing process. On the other hand, zinc metal is safe because it is not explosive. Therefore, it is more promising than lithium secondary battery in electric vehicle battery, and manufacturing process is also performed at room temperature and general air, so the manufacturing cost is low.

In the case of zinc air cells, the electrode is composed of a cathode, which is an air electrode to which oxygen is reduced, and a cathode, which oxidizes zinc. As mentioned above, in order to increase the overall efficiency of the metal air cell, it is important to make the oxygen reduction reaction at the anode relatively slow in the reaction rate. Therefore, the catalyst is adsorbed on the air electrode to make two layers of poles to activate the reduction of oxygen. In the case of the cathode, electrons are generated as the zinc metal is oxidized to the zinc divalent ion, and the electrons move through the external conductor and react with each other while meeting the oxygen, so that the reduction reaction of oxygen occurs.

[Reaction Scheme 1]

Anode reaction: O ₂ + 2H ₂ O + 4e ^- ? 4OH ^-

Cathode reaction: Zn → Zn ^{2 +} + 2e ^-

Zn ^{2 +} + ₄ OH ^{- -} > Zn (OH) ₄ ^2-

Zn (OH) ₄ ^2- → ZnO + H ₂ O + 2OH ^-

When only a carbon cathode is used without using a catalyst, the anodic reaction is not efficiently performed and the oxygen reduction reaction characteristic is poor. Therefore, it is necessary to develop a catalyst for anode, and platinum catalyst which is commercialized has the best characteristics. However, it is disadvantageous in terms of cost and it is necessary to compensate the problem because electrolyte is not an alkaline solution but is poor in a solution such as methanol.

One embodiment of the present invention is to provide a composite catalyst for a zinc air cell that promotes an effective oxygen reduction reaction without containing a metal.

Another embodiment of the present invention is to provide a method for producing the composite catalyst for the zinc air battery.

Another embodiment of the present invention is to provide an air electrode for a zinc air battery including the composite catalyst for the zinc air battery.

Another embodiment of the present invention is to provide a zinc air battery including the air electrode for the zinc air battery.

Embodiments according to the present invention can be used to accomplish other tasks not specifically mentioned other than the above-described tasks.

In one embodiment of the present invention, there is provided a composite catalyst for a zinc air cell, which comprises a carbon black-carbonized gelatin compound and is doped with nitrogen in the compound.

The carbon black may be a conductive carbon black.

The conductive carbon black may be ketjen black.

The nitrogen doping ratio in the compound may be about 0.01 to 0.05 atomic ratio of nitrogen to carbon atoms in the compound.

The carbon black-carbonized gelatin compound may be in the form of a carbon sheet having an amorphous structure.

In one embodiment of the present invention, there is provided a method for manufacturing a zinc air cell, comprising: preparing a gelatin solution by dissolving gelatin in a solvent; preparing a mixture by adding and mixing carbon black to the gelatin solution; and heat- A method for producing a composite catalyst is provided.

In the step of dissolving the gelatin in a solvent to prepare a gelatin solution, the content of gelatin in the gelatin solution may be about 20 to 50% by weight.

In the step of adding and mixing carbon black to the gelatin solution to prepare a mixture, the content of the carbon black in the mixture may be about 1 to 20% by weight.

The heat treatment temperature may be about 650 to 1000 < 0 > C.

The step of heat-treating the mixture may be an argon atmosphere.

Adding the carbon black to the gelatin solution and mixing to prepare a mixture, and then cooling the mixture to obtain the mixture in the form of a jelly.

The composite catalyst obtained by the method for producing a composite catalyst for a zinc air battery may include a carbon black-carbonized gelatin compound and nitrogen doped in the compound.

According to an embodiment of the present invention, there is provided an air electrode for a zinc air battery including a composite catalyst for a zinc air battery according to an embodiment of the present invention.

An embodiment of the present invention is a negative electrode comprising a carbon black-carbonized gelatin compound and a composite catalyst for a zinc air cell in which the compound is doped with nitrogen, a negative electrode comprising a zinc gel or a zinc plate , A separator, and an electrolytic solution containing an aqueous alkali solution.

Provided is a method for manufacturing a composite catalyst for a zinc air cell, which is capable of promoting an oxygen reduction reaction in a zinc air cell cathode and providing a composite catalyst for a zinc air battery with reduced cost, and which is economical and advantageous for mass production .

Also, it is possible to realize a zinc air cell having high energy density characteristics including the same.

1 is a schematic view showing an air electrode for a zinc air battery according to an embodiment of the present invention.
2 is a schematic view showing a zinc air cell according to an embodiment of the present invention.
3 is a schematic diagram of a step of preparing a ketjen black-carbonized gelatin compound according to an embodiment of the present invention.
FIG. 4 shows TEM and fast fourier transform (FFT) photographs of the Ketjen black (A, B) and the heat-treated gelatin samples used in Comparative Example 1, respectively.
FIG. 5 is a graph showing the results of XPS nitrogen 1s orbitals spectra of the composite catalyst for zinc air cells prepared in Examples 1 to 3. FIG.
6 is a graph summarizing the nitrogen content (atomic%) according to the heat treatment temperature in Table 1 described in Experimental Example 2 of the present invention.
7 is a graph showing nitrogen atomic ratios (atomic%) with respect to carbon atoms contained in the composite catalysts of Examples 1 to 3;
8 is a graph showing the results of measurement of current density using RRDE (Rotating Ring Dick Electrode) and a linear scanning voltage method.
9 is a graph showing the results of calculating the number of electrons participating in the oxygen reduction reaction using the result data according to Experimental Example 3 and (1) and (2) of [Equation 1] described in Experimental Example 4. FIG.
10 is a graph showing an experiment result of a current density of 50 mA / cm ² applied in an experiment for measuring a discharge capacity by applying a specific current density to a zinc air cell.
11 is a graph showing an experiment result of a current density of 25 mA / cm ² applied in an experiment for measuring a discharge capacity by applying a specific current density to a zinc air cell.
FIG. 12A is a graph showing various models according to nitrogen content and position, and B is a graph showing analysis of HOMO-LUMO energy difference through a program called GaussSum 2.2.
13 is an XRD analysis graph for Examples 1 to 3 of the present invention.
14 is a Raman spectroscopic analysis graph for Examples 1 to 3 of the present invention.
15 is a graph showing the results of evaluating methanol tolerance by measuring the current density by performing a constant potential test on each of the electrodes including the composite catalyst prepared in Example 2 of the present invention and a platinum catalyst (20 wt% Pt) Fig.
16 is a graph showing the result of measuring the relative current (%) by performing a constant potential test on each of the electrodes including the composite catalyst prepared in Example 2 and a platinum catalyst (20 wt% Pt).

Hereinafter, embodiments of the present invention will be described in detail. However, it should be understood that the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

FIG. 1 is a schematic view showing an air electrode for a zinc air battery according to one embodiment, and FIG. 2 is a schematic view showing a zinc air battery according to an embodiment.

Referring to FIG. 1, the air electrode 110 for a zinc air battery according to an embodiment may include the composite catalyst 111 for a zinc air battery, the carbon carrier 112, and the binder 113 described above.

The air electrode 110 may be formed on the first diffusion layer by forming a slurry together with the composite catalyst 111 for the zinc air battery, the carbon support 112 and the binder 113, A method using a roll press or a hot press, a method using a doctor blade or a roller coater, a method using either electrospinning or electrospray ≪ / RTI >

The air electrode 110 may react with oxygen in the air to cause a reaction represented by the following formula (1).

[Chemical Formula 1]

O ₂ + 2H ₂ O + 4e ^- ? 4OH ^-

The carbon support 112 supports the composite catalyst 111 for the zinc air battery and may specifically include activated carbon, carbon fiber, carbon nanotube (CNT), graphene, and the like.

If only the carbon cathode is used without using the catalyst, the above-mentioned cathode reaction is not efficiently performed and the oxygen reduction reaction characteristic is not good.

Accordingly, in one embodiment of the present invention, there is provided a composite catalyst 111 for a zinc air cell including a carbon black-carbonized gelatin compound and doped with nitrogen in the compound.

In one embodiment of the present invention, the composite catalyst 111 may contain a certain percentage of nitrogen atoms, and the ratio of the nitrogen atoms may be controlled by controlling the ratio of the gelatin material used in the manufacturing step, have. In the case where the composite catalyst 111 containing nitrogen atoms according to an embodiment of the present invention is used as an air electrode of a zinc air battery, the oxygen reduction reaction occurring in the air electrode can be promoted.

Specifically, in one embodiment of the present invention, the carbon black may be a conductive carbon black. More specifically, the conductive carbon black may be ketjen black, and the ketjen black may be highly conductive and uniformly mixed in gelatin. Therefore, when used as the air electrode of a zinc air battery, excellent oxygen reduction characteristics can be exhibited.

The atomic ratio of nitrogen to carbon atoms in the composite catalyst for a zinc air cell, which is an embodiment of the present invention, may be about 0.01 to 0.05. More specifically, it may be 0.01 to 0.02. The specific range can be calculated from FIG. 12, but is not limited thereto. A more specific range can be calculated in Table 1 of Experimental Example 2.

The proper type and ratio of carbon between the carbon of the carbon atom source and the nitrogen from the nitrogen atom source gelatin can be formed within the atomic ratio of nitrogen to improve the ability as an oxygen reduction catalyst .

Nitrogen according to the types of carbon and nitrogen bonds can be classified into pyridinic nitrogen, pyrrolic nitrogen, quaternary nitrogen, oxidized nitrogen, and the like.

In one embodiment of the present invention, the carbon black-carbonized gelatin compound may be in the form of a carbon sheet having an amorphous structure. Specifically, carbon black and gelatin which are in contact with each other in the production step can form new carbon and nitrogen atom bonds. The carbon black-carbonized gelatin compound thus prepared is entirely in the form of a carbon sheet, and the carbon black-carbonized gelatin compound can have a constantly amorphous structure in the outside. In one embodiment of the present invention, since the carbon black-carbonized gelatin compound sheet structure is in the form of a carbon sheet having a constant amorphous structure inside and outside, it functions as a composite catalyst having excellent activity . One embodiment of the present invention is a method for producing a zinc air cell, comprising the steps of preparing a gelatin solution by dissolving gelatin in a solvent, preparing a mixture by adding and mixing carbon black to the gelatin solution, and heat- And a method for producing the composite catalyst 111 is provided.

Hereinafter, one embodiment of the present invention will be described in detail for each step.

First, the step of dissolving gelatin in a solvent to prepare a gelatin solution is a step for preparing a mixed solution by dissolving gelatin in a solvent. The solvent may be specifically water. Specifically, in the step of dissolving the gelatin in a solvent to prepare a gelatin solution, a pretreatment in which gelatin is added to water and is called at room temperature for about 30 minutes to 1 hour can be performed.

After the step of preparing the gelatin solution, stirring can be additionally performed for a certain period of time so that the effective gelatin is mixed with the solvent. For example, mixing can be effected by stirring at room temperature for about 2 to 4 hours.

In the step of dissolving the gelatin in a solvent to prepare a gelatin solution, the content of gelatin in the gelatin solution may be 20 to 50% by weight. More specifically from 30 to 35% by weight. In the step of adding the carbon black which can be carried out within the above range of the gelatin content, it is possible to have a viscosity and a physical property which can be easily dispersed in the carbon black to be added, Can be controlled.

Next, the step of adding and mixing carbon black to the gelatin solution to prepare a mixture is performed by mixing carbon black, which is a carbon atom source, with nitrogen to form a carbon-nitrogen bond having excellent oxygen reduction characteristics in the produced composite catalyst 111, To a solution containing gelatin, which is an atomic source.

Specifically, the carbon black may be a conductive carbon black. More specifically, the conductive carbon black may be ketjen black, and the ketjen black is a composite catalyst prepared by mixing with gelatin which is highly conductive and can be uniformly mixed in gelatin and is a source of mixed nitrogen atoms 0.0 > (111) < / RTI >

In addition, the weight ratio of the carbon black to the gelatin material in the mixture may be about 1 to 20 wt%. More specifically, it may be 5 to 10% by weight. It is possible to effectively disperse the carbon black in the gelatin solution within a weight ratio of the carbon black and control the ratio of carbon to nitrogen in the composite catalyst to be produced within a range that exhibits excellent oxygen reduction characteristics.

Next, the step of heat-treating the mixture of carbon black is performed, thereby not only removing the solvent in the mixture but also controlling the ratio of the nitrogen atoms present in the composite catalyst 111 to be produced. Specifically, when the heat treatment is performed at a relatively high temperature, the nitrogen atom ratio in the composite catalyst 111 produced by performing the heat treatment at a relatively low temperature is low.

The heat treatment temperature may be about 650 to 1000 < 0 > C. More specifically, it may be about 850 to 950 < 0 > C. The heat treatment time may be about 30 minutes to 1 hour and 30 minutes.

It is possible to control the nitrogen atoms contained in the composite catalyst 111 manufactured within the heat treatment temperature range and to exhibit excellent oxygen reduction characteristics.

Specifically, the heat treatment can be performed in an argon atmosphere.

In one embodiment of the present invention, the step of adding the carbon black to the gelatin solution and mixing the mixture to prepare the mixture may further include cooling the mixture to obtain the mixture in the form of a jelly. The obtained jelly-like mixture can maintain the dispersed form of the carbon black in a fixed state, and can control the dispersed form during the subsequent heat treatment process.

3 is a schematic diagram of a step of preparing a ketjen black-carbonized gelatin compound according to an embodiment of the present invention.

Referring to FIG. 3, it can be confirmed that gelatin according to an embodiment of the present invention has both hydrophobicity and hydrophilicity, so that it can be easily mixed with a hydrophilic solvent and hydrophobic carbon black.

Specifically, Fig. 3 (a) is a photograph of a state in which 25 g of gelatin is dissolved in water in Experimental Example 2, and (b) 2 g of Ketjen Black powder is added and mixed in a mixed solution of 25 g of gelatin dissolved in Experimental Example 2 And c is a photograph of a Ketjenblack-carbonized gelatin compound after the heat treatment in Experimental Example 2. FIG.

In one embodiment of the present invention, the composite catalyst 111 obtained by the method for producing the composite catalyst 111 for a zinc air battery includes a carbon black-carbonized gelatin compound, and the nitrogen-doped Lt; / RTI >

Referring to FIG. 1, the binder 113 may include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), and the like. However, There is no particular limitation as long as it is a material that can block water flowing into the air electrode to maintain the hydrophobicity of the air electrode and prolong the life of the battery.

Hereinafter, a zinc air cell including the air electrode will be described with reference to FIG.

2 is a schematic diagram illustrating a zinc air cell according to one embodiment.

2, a zinc air cell according to an embodiment includes a cathode 120 including a cathode or anode 110, a zinc gel or a zinc plate, a separator 120 interposed between the cathode 110 and the cathode 120, An electrolyte 130, and an electrolytic solution.

Further, it may further comprise a case 140 surrounding the entire zinc air cell. The case 140 according to one embodiment functions as an exterior material of the zinc air cell to protect the entire components. An air hole 141 may be formed on the upper surface of the case 140, that is, on the surface adjacent to the air electrode 110, so that the air electrode 110 reacts with oxygen in the air to perform a chemical reaction of the chemical formula 1. In addition, a terminal exposed portion 142 may be formed on the surface of the case, that is, on the surface adjacent to the cathode portion 120, so that the anode terminal of the zinc air battery is extended to be exposed to the outside.

The air electrode 110 is as described above.

The cathode part 120 generates a chemical reaction represented by the following formula (2).

(2)

Zn - > Zn ₂ + + 2e ^-

Zn ₂ + + 4OH-? Zn (OH) ₄ ^2-

Zn (OH) ₄ ^2- → ZnO + H ₂ O + 2OH ^-

Examples of the zinc gelling agent include carboxymethyl cellulose, hydroxypropylmethyl cellulose, gelatin, polyvinyl alcohol, polyethylene oxide, polybutylvinyl alcohol, alcohol, polyzincrylic acid, and polyacrylic amide. However, the present invention is not limited thereto.

The separator 130 is disposed under the air electrode 110 to separate the air electrode 110 and the cathode unit 120 from each other. The separator 130 may be bonded to the lower surface of the composite catalyst for a zinc air battery, which is one component of the air electrode 110. As described above, the air electrode 110 generates a hydroxide ion or the like by causing a reaction of the formula (1). The hydroxide ion should be transmitted to the cathode unit 120 through the separator 130. Therefore, the separator 130 may be made of a material having ion permeability, specifically, polypropylene, teflon, polyethylene, polytetrafluoroethylene (PTFE), nylon membrane filter, and nonwoven fabric.

The electrolytic solution may include an aqueous alkali solution, and specifically, potassium hydroxide, sodium hydroxide, lithium hydroxide, or the like may be used, but the present invention is not limited thereto.

One or more gelling agents selected from the above materials may be rapidly stirred into a selected alkaline electrolytic solution or dissolved by ultrasonic dispersion, and then zinc may be added to the electrolytic solution to form a zinc gel.

An embodiment of the present invention is a carbon black-carbonated gelatin compound, and a cathode, a zinc gel or a zinc plate containing a composite catalyst (111) for a zinc air cell doped with nitrogen in the compound, A separator, and an electrolyte solution containing an aqueous alkaline solution.

The composite catalyst 111 for a zinc air cell or the zinc air cell including the air electrode according to an embodiment of the present invention minimizes deterioration of electrical and chemical characteristics without using a metal material in the manufacturing process, This is possible.

Hereinafter, specific embodiments of the present invention will be described. It is to be understood, however, that the embodiments described below are only for illustrative purposes or to illustrate the present invention, and the present invention should not be limited thereby.

< Example  1> Preparation of composite catalyst

50 g of distilled water and 25 g of gelatin are mixed to prepare a mixed solution. Thereafter, the gelatin is stirred at about 60 캜 for about 3 hours until the gelatin is completely dissolved in the water.

Next, 2 g of ketjen black, which is carbon black, is mixed with the mixed solution in which gelatin is dissolved and stirred, and stirred until uniformly dispersed. Then, the mixed solution in which the ketjen black is uniformly dispersed is cooled at about 3 캜 for about 30 minutes to produce a jelly-like substance. Next, the produced jelly-like material is placed in a tube furnace under argon gas atmosphere and heat-treated at about 800 ° C for about 1 hour to obtain a composite catalyst for a zinc air cell.

< Example  2> Preparation of composite catalyst

A composite catalyst for a zinc air battery was obtained in the same manner as in Example 1 except that the heat treatment temperature was set at about 900 ° C.

< Example  3> Preparation of composite catalyst

A composite catalyst for a zinc air cell was obtained in the same manner as in Example 1, except that the heat treatment temperature was set at about 1000 캜.

< Example  4> Manufacture of zinc air cell

In order to manufacture a zinc air cell according to an embodiment of the present invention, a zinc air cell is manufactured as follows.

About 0.75 grams of zinc powder is wetted with about 200 microns of aqueous solution of about 6 moles of KOH for the cathode formation.

Then, in order to form a separation membrane, a nylon membrane is laminated on the negative electrode.

Next, an active carbon powder and a polytetrafluoroethylene (PTFE) mixture are laminated on a nickel mesh to prepare an air electrode in which a catalyst layer is not present, and is placed on the separator.

The content of the mixture in the air electrode is about 60% by weight. The weight ratio of active carbon powder and polytetrafluoroethylene in the mixture is about 7: 3 (activated carbon powder: polytetrafluoroethylene).

Next, using the method of making the composite catalyst powder as an ink on the air electrode on which the catalyst layer does not exist, and dropping the ink onto the air electrode on which the catalyst layer does not exist to perform vacuum adsorption, the zinc air battery produced in Example 1 A zinc cathode comprising a composite catalyst is prepared.

The ink was prepared by mixing about 12 mg of the composite catalyst for zinc air cell prepared in Example 1, about 400 microliters of about 0.05% Nafion solution and about 1600 microliters of ethanol and performing ultrasonic treatment for about 1 hour .

< Example  5> Manufacture of zinc air cell

A zinc air cell was manufactured in the same manner as in Example 4, except that the composite catalyst powder used for the production of the ink was the composite catalyst for a zinc air cell produced in Example 2 .

< Example  6> Manufacture of zinc air cell

A zinc air cell was manufactured in the same manner as in Example 4 except that the composite catalyst powder used for the production of the ink was the composite catalyst for zinc air battery prepared in Example 3 .

< Comparative Example  1> Preparation of catalyst by simple physical mixing

25 g of gelatin is sampled and the sample heat-treated at about 900 ° C is physically simply mixed with 2 g of Ketjenblack powder to prepare a mixed powder type catalyst.

< Experimental Example  1> Transmission scanning microscope ( TEM ) Analysis

FIG. 4 shows TEM and Fast Fourier transform (FFT) photographs of each of the keten black (A, B) and the heat-treated gelatin sample used in Comparative Example 1. FIG.

As a result, it is observed that Ketjenblack, carbonized gelatin, and the Ketjenblack-carbonized gelatin compound prepared in Example 2 of the present invention all have a carbon sheet form.

Specifically, referring to FIGS. 4A and 4B, the Ketjenblack shows that the outer boundary portion has a relatively ordered structure, that is, a crystalline structure, or a disdordered structure inside, that is, an amorphous ) Structure.

Referring to FIGS. 4C and 4D, the carbonated gelatin has a relatively ordered structure, that is, a crystalline structure, or an internally disdordered structure, that is, an amorphous structure . Referring to FIGS. 4E and 4F, it can be seen that the Ketjenblack-carbonized gelatin compound prepared in Example 2 of the present invention has a constant internal and external structure and is amorphous (disordered). Here, the image in the upper right square box in F in FIG. 4 is an FFT image obtained by enlarging the circle portion indicated by E in FIG.

< Experimental Example  2> XPS  Analysis

FIG. 5 is a graph showing the results of XPS nitrogen 1s orbitals spectra of the composite catalyst for zinc air cells prepared in Examples 1 to 3. FIG. In FIG. 5, N-6 represents pyridinic nitrogen, N-5 represents pyrrolic nitrogen, NQ represents quaternary nitrogen, and NX represents oxidized nitrogen .

Referring to FIG. 5, it can be seen that the relative amount of N-Q is greater than N-6 as the heat treatment temperature in the composite catalyst preparation step is increased.

The following Table 1 summarizes the existence ratio of carbon, nitrogen and oxygen according to the XPS analysis result of Experimental Example 2. Each of the sample name GK-800 corresponds to the composite catalyst prepared in Example 1, GK-900 to Example 2 and GK-1000 corresponds to the composite catalyst prepared in Example 3.

Referring to Table 1 below, it can be seen that the amount of nitrogen decreases as the heat treatment temperature in the production step increases.

7 is a graph showing the nitrogen atomic ratio (atomic%) of the carbon atoms contained in the composite catalysts of Examples 1 to 3, Fig.

As a result, it can be seen that the nitrogen content and the kind in the composite catalyst can be controlled by controlling the heat treatment temperature in the production step.

< Experimental Example  3> Linear scan Voltage method  Results analysis

In order to evaluate the current density with respect to the applied voltage of the electrode including the composite catalyst according to an embodiment of the present invention, the current density is measured using a rotating ring dick electrode (RRDE) and a linear scanning voltage method. The measurement results are shown in Fig.

Specifically, the same procedure as in Example 4 for preparing the composite catalyst powder and the platinum catalyst (20 wt% of Pt) prepared in Examples 1 to 3 and Comparative Example 1 was carried out in the same manner as in Example 4, To prepare a composite catalyst ink. Each of the composite catalyst inks prepared above was vacuum-adsorbed for 5 minutes on a glassy carbon electrode for about 10 minutes, immersed in 0.1 M KOH solution (oxygen-saturated), and rotated at 1600 rpm to form an experimental system do. At this time, the system is a system in which platinum counter electrode and Hg / HgO reference electrode are also dipped together with glassy carbon. In the case of the linear scanning voltage method, the scanning speed is set to about 10 mV / s and the voltage range is scanned from about 0.2 V to -0.7 V.

The measured current density in each system was measured, and the results are shown in FIG.

Referring to FIG. 8, it can be confirmed that the current density is slightly superior to the case of containing the composite catalyst of Example 2, as compared with the case of containing the platinum catalyst (20 wt% of Pt).

< Experimental Example  4> Comparison of number of electrons involved in oxygen reduction reaction

In order to evaluate the oxygen reduction characteristics of the composite catalyst according to an embodiment of the present invention, the number of electrons participating in the oxygen reduction reaction is calculated as follows.

The number of electrons involved in the oxygen reduction reaction is calculated using the result data according to Experimental Example 3 and (1) and (2) shown below in FIG.

[Equation 1]

(1)H ₂ O ^- (%) = 100

(One)

(2)

(2 )

At this time, each variable Ir is a ring current, Id is disk current, and N is a collection efficiency.

Here, when N is 10 mM K ₃ [Fe (CN) ₆ ] in an argon atmosphere, a value of 0.41 is obtained. In the case of Id and Ir described above, it is possible to obtain by using the data values in FIG. 8, and substitute each variable into the above equation 1 to finally obtain the number n of electrons.

Referring to FIG. 9, the closer the number of electrons is to 4, the more dominant the 4-electron reaction. The closer to 2, the more dominant the 2-electron reaction. . Therefore, it can be seen that the efficiency of the oxygen reduction reaction is not lowered in Examples 1 to 3 as compared with the case of including the platinum catalyst.

< Experimental Example  5> Evaluation of Discharge Characteristics of Zinc Air Battery

A zinc air cell manufactured in Example 5 of the present invention is prepared. The same procedure as in Example 5 was carried out except that a platinum catalyst (20 wt% Pt) was used in place of the composite catalyst for a zinc air cell produced in Example 2 in Example 5, Prepare an air cell. Experiments to measure the discharge capacity by applying a specific current density to the two zinc air cells are performed. Figures 10 and 11 show the results. In Figure 10, each in the current density is 50mA / cm ^2, 11 corresponds to the graph in the case of 25 mA / cm ^2.

10 and 11, in the case of the zinc air cell manufactured in Example 5, the initial discharge capacity and the discharge capacity were longer than those of the zinc air cell having the air electrode containing the platinum catalyst (20 wt% Pt) .

< Experimental Example  6> Depending on nitrogen content and position HOMO - LUMO  Energy difference evaluation

FIG. 12 is a graph showing the results of analysis of HOMO-LUMO energy difference through a program called GaussSum 2.2 after modeling various models according to nitrogen content and position as shown in FIG. 12A. Considering the case where 2, 4, or 6 are doped from the case of no nitrogen content, each nitrogen position is also measured at various positions from the outside to the inside. Referring to FIG. 12B, there are points at which the HOMO-LUMO energy difference becomes the minimum (four in the inner basal and the edge (pyridinic) and two in the outer basal) depending on the specific nitrogen content, It can be seen as the nitrogen content that gives the best response. It can be seen that the nitrogen content in the composite catalyst exhibits the best oxygen reduction reaction capability when an appropriate level of nitrogen is doped.

< Experimental Example  7> XRD  And Raman spectra analysis results

XRD analysis was performed on Examples 1 to 3 of the present invention and is shown in Fig. In addition, Raman spectra analysis was performed on Examples 1 to 3 of the present invention, and it is shown in Fig.

Referring to FIG. 13, it can be seen that the carbonated gelatin-Ketjenblack catalyst, which is the composite catalyst prepared in Examples 1 to 3, is an amorphous structure,

Referring to FIG. 14, it can be seen that the I (D / G) ratio decreases as the heat treatment temperature increases.

< Experimental Example  8> Methanol tolerance test

Each of the electrodes including the composite catalyst prepared in Example 2 and the platinum catalyst (20 wt% Pt) was prepared separately from the step of preparing the air electrode of Example 4.

Each of the prepared electrodes was subjected to a constant potential test under a condition of about -0.2 V (vs Hg / HgO) at 1600 rpm and a 0.1 M KOH electrolyte saturated with oxygen. Methanol was added to the KOH aqueous solution at about 150 seconds When dropped, perform an experiment to observe the current change. The results are shown in Fig.

Referring to FIG. 15, the electrode containing the composite catalyst prepared in Example 2 showed no significant change in current. However, in the case of an electrode including a platinum catalyst (20 wt% Pt) . As a result, it can be confirmed that the electrode including the composite catalyst according to an embodiment of the present invention has excellent resistance to methanol.

< Experimental Example  9> Electrostatic potential immunity test

Each of the electrodes including the composite catalyst prepared in Example 2 and the platinum catalyst (20 wt% Pt) was prepared separately from the step of preparing the air electrode of Example 4.

For each of the electrodes, the relative current (%) is measured by running the constant potential test under the condition of -0.2 V (vs Hg / HgO) at 1600 rpm and 0.1 M KOH electrolyte saturated with oxygen for about 20000 seconds. The results are shown in Fig.

In the case of the electrode including the composite catalyst prepared in Example 2, the current intensity was about 79% in the case of the catalyst at 20000 seconds compared to the current intensity at the start, but the platinum catalyst (20 wt% Pt) It is found that the composite catalyst according to one embodiment of the present invention is excellent in terms of durability because it is about 48%

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims. As will be understood by those skilled in the art. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

110: air electrode
111: composite catalyst
112: Carbon carrier
113: binder
120: cathode part
130: Separator
140: Case
141: air hole
142: Terminal exposed portion

Claims (14)

Carbon black - a carbonized gelatin compound,
Nitrogen in the compound is doped,
The nitrogen doping ratio in the compound is,
Wherein the atomic ratio of nitrogen to carbon atoms in the compound is 0.01 to 0.05. The method of claim 1,
Wherein the carbon black is a conductive carbon black. 3. The method of claim 2,
Wherein the conductive carbon black is ketjen black. delete The method of claim 1,
The carbon black-carbonized gelatin compound may be prepared by,
Composite catalyst for zinc air cell in the form of a carbon sheet having an amorphous structure. Dissolving gelatin in a solvent to prepare a gelatin solution,
Adding and mixing carbon black to the gelatin solution to prepare a mixture, and
Heat treating the mixture,
&Lt; / RTI &gt; wherein the method comprises the steps of: The method of claim 6,
In the step of dissolving the gelatin in a solvent to prepare a gelatin solution,
Wherein the content of gelatin in the gelatin solution is 20 to 50 wt%. The method of claim 6,
In the step of adding and mixing carbon black to the gelatin solution to prepare a mixture,
Wherein the content of the carbon black in the mixture is 1 to 20 wt%. The method of claim 6,
Wherein the heat treatment temperature is 650 to 1000 占 폚. The method of claim 6,
Wherein the step of heat-treating the mixture is an argon atmosphere. The method of claim 6,
After adding the carbon black to the gelatin solution and mixing to prepare the mixture,
And cooling the mixture to obtain the mixture in the form of a jelly. The method of claim 6,
The composite catalyst obtained by the method for producing a composite catalyst for a zinc air battery,
A process for preparing a composite catalyst for a zinc air cell, the carbon black comprising a carbonized gelatin compound and doped with nitrogen in the compound. A cathode for a zinc air battery, comprising the composite catalyst for a zinc air battery according to any one of claims 1 to 3 and 5. Carbon black-carbonized gelatin compound, wherein the nitrogen doping ratio in the compound is such that the atomic ratio of nitrogen to carbon atoms in the compound is from 0.01 to 0.05. An air electrode comprising a composite catalyst;
A negative electrode comprising a zinc gel or zinc plate;
A separator; And
An electrolyte solution containing an aqueous alkali solution
Gt;

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