KR20200066939A - The aluminum anode for aluminum-air using recycling aluminum can and aluminum-air containing the same - Google Patents

Abstract

The present invention relates to an aluminum electrode for an aluminum air battery in which aluminum cans are recycled, a method for manufacturing an aluminum air battery comprising the same, and an electrode of the aluminum air battery manufactured thereby.

Description

A method for manufacturing an electrode of an aluminum air battery and an aluminum air battery electrode produced thereby{The aluminum anode for aluminum-air using recycling aluminum can and aluminum-air containing the same}

The present invention relates to a method for manufacturing an electrode of an aluminum air battery using a recycled aluminum can that can recycle resources, be environmentally friendly, and increase industrial competitiveness, and an aluminum air battery electrode produced thereby.

Aluminum cans are recycled packaging containers that can efficiently recycle waste aluminum cans, which is very important not only for environmental conservation but also for recycling resources. In particular, considering the reality that most of the demand for aluminum, including raw materials for aluminum cans, is dependent on imports, recycling of waste aluminum cans is very important in terms of import substitution effects.

Waste aluminum cans and packaging materials generate about 276,000 tons annually in Korea. More than 90% is collected, but the officially estimated recycling rate is around 60%. The waste aluminum can is washed, crushed, removed from impurities and paint, and then heated and melted at a temperature of about 700°C or higher, and then regenerated into an aluminum alloy.

In general, recycling of waste aluminum cans is accomplished through heating and melting, which leads to large amounts of fuel consumption, gas removal of impurities in the paint removal and melting process, generation of CO ₂ and SOx, dust generation from melting residues, etc. Several problems arise that cause environmental pollution problems. In addition, it is a situation that shows a recovery rate of aluminum of 60% to 70% due to high oxidation of aluminum itself and an increase in melting temperature due to inclusions and oxides in molten metal.

Therefore, research on the creation and recycling of a new recycling market is needed to increase the recycling ratio of waste aluminum cans and create high added value.

An object of the present invention is to provide an aluminum air battery electrode and an aluminum air battery produced thereby by recycling waste aluminum cans.

In addition, the present invention is an eco-friendly and economical aluminum can by measuring the current-voltage (IV) and current-output (IP) characteristics of the battery by applying the aluminum electrode recycled to the waste aluminum can to the aluminum-air battery system. It aims to develop a recycling plan.

The recycling method of an aluminum can for one purpose of the present invention is a method of producing a aluminum alloy electrode for an aluminum-air battery by compressing and molding a scrap after performing a painting removal and crushing process without a melting process in the prior art and the aluminum alloy electrode It includes a method of manufacturing an aluminum air battery to which it is applied.

The recycling method of aluminum cans for another purpose of the present invention is a mixture of a binder and a mixture is made by drying the mixture on a current collector without a melting process in the prior art and selectively proceeding with crushing while selectively removing the coating. It includes a method of producing an aluminum alloy electrode for an air battery and a method of manufacturing an aluminum air battery using the aluminum alloy electrode.

In addition, the present invention is manufactured by the above method, and provides an environmentally friendly aluminum air battery electrode and air battery.

According to the present invention, aluminum cans are recycled and applied to aluminum air cell electrodes and air cells, thereby securing economical and eco-friendly electrical energy compared to the prior art.

The present invention, compared to the conventional aluminum alloy for aluminum air battery, has the effect of having a high initial electromotive force, it was confirmed that it has a high current density and output density under the same discharge voltage.

Figure 1a is a flow chart of a method for manufacturing an electrode of an aluminum air battery according to the paint removal step of the present invention.
1B is a flow chart of a method for manufacturing an electrode of an aluminum air battery according to the binder-mixing step of the present invention.
2 is a view showing the results of the polarization test of the coin using the aluminum can recycling electrode according to an embodiment of the present invention.
3 is a view showing the results of measuring the current density and voltage (IV characteristic) of an aluminum-air battery using an aluminum can recycling electrode according to an embodiment of the present invention, respectively.
4 is a view showing the results of measuring the discharge current density and the output density (IP characteristics) of the aluminum-air battery using the aluminum can recycling electrode according to an embodiment of the present invention, respectively.

Hereinafter, an embodiment of the present invention will be described in detail. The present invention can be applied to various changes and may have various forms, and specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosure form, and it should be understood as including all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing each drawing, similar reference numerals are used for similar components. In the accompanying drawings, the dimensions of the structures are shown to be enlarged than the actual for clarity of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from other components. For example, the first component may be referred to as a second component without departing from the scope of the present invention, and similarly, the second component may be referred to as a first component.

The terms used in the present application are only used to describe specific embodiments and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "include" or "have" are intended to indicate that a feature, step, operation, component, part, or combination thereof described on the specification exists, one or more other features or steps. It should be understood that it does not preclude the existence or addition possibility of the operation, components, parts or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. Terms, such as those defined in a commonly used dictionary, should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

Method for manufacturing an electrode of an aluminum air battery according to an embodiment of the present invention, preparing an aluminum can; Removing the coating on the outside of the aluminum can; And compression molding the aluminum can.

1A is a flowchart of a method of manufacturing an electrode of an aluminum air battery according to an embodiment of the present invention.

According to Figure 1a, preparing an aluminum can (S 110); Removing the coating on the outside of the aluminum can (S 140); And compression molding the aluminum can (S 150).

In this case, after the step of preparing the aluminum can (S 110), the step of crushing the aluminum can (S 120) may be further included.

After the step of crushing the aluminum can (S 120), the step of screening the aluminum can (S 130) may be further included.

In step S 110, an aluminum can is prepared. The preparation of the aluminum cans can be done in any way, and there is no particular limitation.

In step S 120, the aluminum can is crushed. The crushing proceeds to a certain size, and there is no particular limitation on this, but a size of 50 mm to 200 mm is suitable.

In step S 130, aluminum cans are sorted, and in this case, aluminum cans that are difficult to recycle or for other reasons are removed, and there is no particular limitation on this step.

In step S 140, the painting on the outside of the aluminum can is removed. Removal of the external coating can be removed by treatment for 10 minutes to 30 minutes under a hot air of 500° C. or more and 660° C. or 5 minutes to 20 minutes in an acid solution having a concentration of 90% to 98% at room temperature.

When removing the coating on the outside of the aluminum can under the hot air, a temperature of less than 500°C is difficult to remove the coating on the outside of the aluminum can, and the melting point of aluminum is 660°C. Because the aluminum can is melted, it is difficult to remove only the coating on the outside of the aluminum can.

When removing the coating on the outside of the aluminum can in an acid solution having a concentration of 90% to 98% at room temperature, the acid solution used is preferably sulfuric acid (H ₂ SO ₄ ).

In step S 150, an aluminum can is subjected to compression molding, and it is preferable to mold at a normal temperature with a compression force of 630 kN or more. If the compressive force is less than 630 kN, the compressive force is weak, so that sufficient compression is not achieved when recycling the aluminum can, and the efficiency may be lowered due to internal empty space or the like when used as an electrode in the future.

Method for manufacturing an electrode of an aluminum air battery according to another embodiment of the present invention, preparing an aluminum can; Crushing the aluminum can; Mixing a crushed piece of the aluminum can and a binder to form a mixture; The step of fixing the mixture to the current collector: and drying the mixture fixed to the current collector.

1B is a flowchart of a method of manufacturing an electrode of an aluminum air battery according to another embodiment of the present invention.

According to Figure 1b, preparing an aluminum can (S 210); Crushing the aluminum can (S 250); Mixing a crushed piece of the aluminum can and a binder to make a mixture (S 260); Fixing the mixture to a current collector (S 270); And drying the mixture fixed to the current collector (S 280).

In this case, after the step of preparing the aluminum can (S 210), the step of crushing the aluminum can (S 220) may be further included.

After the step of crushing the aluminum can (S 220), the step of screening the aluminum can (S 230) may be further included.

After the step of selecting the aluminum can (S 230), the step of removing the coating of the exterior of the aluminum can (S 240) may be further included.

In step S 210, an aluminum can is prepared. The preparation of the aluminum cans can be done in any way, and there is no particular limitation.

In step S 220, the aluminum can is crushed. The crushing proceeds to a certain size, and there is no particular limitation on this, but a size of 50 mm to 200 mm is suitable.

In step S 230, aluminum cans are sorted, and in this case, aluminum cans that are difficult to recycle or for other reasons are removed, and there is no particular limitation.

In step S 240, the painting on the outside of the aluminum can is removed. Removal of the external coating can be removed by treatment for 10 minutes to 30 minutes under a hot air of 500° C. or more and 660° C. or 5 minutes to 20 minutes in an acid solution having a concentration of 90% to 98% at room temperature.

When removing the coating on the outside of the aluminum can under the hot air, a temperature of less than 500°C is difficult to remove the coating on the outside of the aluminum can, and the melting point of aluminum is 660°C. Because the aluminum can is melted, it is difficult to remove only the coating on the outside of the aluminum can.

When removing the coating on the outside of the aluminum can in an acid solution having a concentration of 90% to 98% at room temperature, the acid solution used is preferably sulfuric acid (H ₂ SO ₄ ).

In step S 250, the aluminum can is crushed. At this time, the size of the aluminum cans to be crushed is 1 mm to 30 mm.

In step S260, a mixture of crushed pieces of aluminum cans and a binder is prepared. The resulting mixture contains crushed pieces of aluminum cans of 40% by weight or more and 10% by weight or less of polyvinylidene fluoride (PVDF), and 5% by weight or less of carbon black And, it is a mixture of a binder consisting of a solution containing 30% to 50% by weight of methyl pyrrolidone (N-Methyl-2-Pyrrolidone (NMP)).

In step S 270, the mixture is fixed to the current collector. At this time, the current collector used is a commercial aluminum alloy processed to a thickness of 0.3 mm to 3 mm to prevent separation of the mixture from the electrode. In the embodiment of FIG. 1B, since a pulverization process is performed, a large number of separation points may be present when fabricated as an electrode of an aluminum air battery, and thus, the electrode efficiency is prevented from being reduced by attaching to the current collector and detaching the electrode. In the embodiment of FIG. 1A, a separate current collector may not be required because it is directly compression-molded without going through a crushing process.

In step S 280, the mixture fixed to the current collector is dried. The mixture is dried at a temperature of 80°C to 130°C for at least 2 hours.

Example 1

Production of electrodes and electrolytes utilizing waste aluminum cans

Sodium hydroxide (NaOH) was used in deionized water having an electrical resistance of 15 MΩ or higher to prepare an electrolyte solution having a pH of 14 or higher. In this solution environment, the aluminum surface loses passivation properties and promotes oxidation, so an aqueous sodium hydroxide (NaOH) solution was set as the electrolyte in this experiment. In this electrolyte environment, an electrode using an aluminum can was applied to confirm the effect of the invention.

In this experiment, the paint on the surface of the aluminum can was removed through sulfuric acid (H ₂ SO ₄ ), and compressed to produce an aluminum alloy electrode for an aluminum-air battery.

Example 2

Battery characteristics test of aluminum-air battery using waste aluminum can recycle electrode

The aluminum electrode and the conventional aluminum alloy according to an embodiment of the present invention were processed into a form for evaluating the properties of an aluminum-air battery, respectively, and the electrochemical characteristics and battery characteristics of the electrode in a 4M sodium hydroxide (NaOH) aqueous solution at room temperature were 3 It was evaluated more than once. As an aluminum alloy used as a reference alloy electrode, pure aluminum having a purity of 99.5% and 99.99% was used. As a reference electrode for evaluating the electrochemical properties, a saturated caromel electrode (SCE) was used, and a counter electrode was used for graphite.

Experimental Example 1: Potentiodynamic polatization test

This experiment was conducted by continuously changing the voltage in the range of ±1 기준 based on the corrosion potential of the electrode in a three-electrode system at a rate of 10 mＶ/min, and measuring the current density at each voltage. Through this experiment, it was confirmed that the electrode using the aluminum can exhibits similar corrosion potential and corrosion rate compared to a purity of 99.99% aluminum alloy, and exhibits more active anode polarization characteristics at a potential of -1.4 V (vs SCE) or higher.

Experimental Example 2: Current-voltage characteristic evaluation (I-V curve)

In this experiment, in the aluminum air battery system, the voltage having a range of 0 to 1.6 Ｖ was continuously increased at a rate of 10 mＶ/min, and the experiment was conducted by measuring the current density at each voltage. In addition, the limit voltage in this experiment was set to 0 mA. Through this experiment, it can be seen that the electrode using the aluminum can exhibits a higher electromotive force at the same discharge current density than the 99.5% purity aluminum alloy, and a higher electromotive force than the purity 99.99% aluminum at a constant discharge current density or higher.

Experimental Example 3: Current-output characteristic evaluation (I-P curve)

In the current-voltage characteristics obtained in Experimental Example 2, the output density was calculated by multiplying the voltage values appearing at a specific current value, and the discharge current density of the battery according to the calculated output density was measured. Through this experiment, it can be seen that the maximum output density of the aluminum can recycling electrode is about 5 mW/cm ² higher than that of the reference aluminum alloy electrode. Therefore, it was confirmed that the recycled electrode exhibits improved aluminum-air battery output characteristics than the reference alloy.

Although described above with reference to preferred embodiments and experimental examples of the present invention, those skilled in the art variously modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. And can be changed.

Claims (20)

Preparing an aluminum can;
Removing the coating on the outside of the aluminum can; And
Compress molding the aluminum can,
Method for manufacturing an electrode of an aluminum air battery.
According to claim 1,
After the step of preparing the aluminum can,
Further comprising the step of crushing the aluminum can,
Method for manufacturing an electrode of an aluminum air battery.
According to claim 2,
The step of crushing the aluminum can,
Comprising the step of crushing to a size of 50mm to 200mm
Method for manufacturing an electrode of an aluminum air battery.
According to claim 2,
After the step of crushing the aluminum can,
Further comprising the step of screening the aluminum can,
Method for manufacturing an electrode of an aluminum air battery.
According to claim 1,
The step of removing the coating on the outside of the aluminum can,
Comprising the step of treating for 10 minutes to 30 minutes under a hot air of 500 ℃ or more and 660 ℃ or less, or 5 to 20 minutes in an acid solution at a concentration of 90% to 98% at room temperature,
Method of manufacturing an electrode of an aluminum air battery
The method of claim 5,
The acid solution is characterized in that the sulfuric acid (H ₂ SO ₄ ) solution
Method of manufacturing an electrode of an aluminum air battery
According to claim 1,
The compression molding step,
Comprising the step of forming an aluminum plate having a thickness of 50mm or more by applying a compression force of 630kN or more at room temperature,
Method for manufacturing an electrode of an aluminum air battery.
Prepared according to the method of any one of claims 1 to 7,
Electrode of aluminum air battery.
Preparing an aluminum can;
Crushing the aluminum can;
Mixing a crushed piece of the aluminum can and a binder to form a mixture;
Fixing the mixture to a current collector; And
Drying the mixture fixed to the current collector,
Method for manufacturing an electrode of an aluminum air battery.
The method of claim 9,
After the step of preparing the aluminum can,
Further comprising the step of crushing the aluminum can,
Method for manufacturing an electrode of an aluminum air battery.
The method of claim 10,
The step of crushing the aluminum can,
Comprising the step of crushing to a size of 50mm to 200mm
Method for manufacturing an electrode of an aluminum air battery.
The method of claim 10,
After the step of crushing the aluminum can,
Further comprising the step of screening the aluminum can,
Method of manufacturing an electrode of an aluminum air battery
The method of claim 12,
After the step of screening the aluminum can,
Further comprising the step of removing the coating on the outside of the aluminum can,
Method for manufacturing an electrode of an aluminum air battery.
The method of claim 13,
The step of removing the coating on the outside of the aluminum can,
Comprising the step of treating for 10 minutes to 30 minutes under a hot air of 500 ℃ or more and 660 ℃ or less, or 5 to 20 minutes in an acid solution at a concentration of 90% to 98% at room temperature,
Method of manufacturing an electrode of an aluminum air battery
The method of claim 14,
The acid solution is characterized in that the sulfuric acid (H ₂ SO ₄ ) solution
Method of manufacturing an electrode of an aluminum air battery
The method of claim 9,
The step of crushing the aluminum can,
Comprising the step of crushing to a size of 1mm to 30mm
Method for manufacturing an electrode of an aluminum air battery.

The method of claim 9,
The step of making a mixture by mixing the crushed pieces of the aluminum can and a binder,
Crushed pieces of aluminum cans of at least 40% by weight,
10% by weight or less of polyvinylidene fluoride (Polyvinylidene fluoride (PVDF)), 5% by weight or less of carbon black (Carbon black), 30% by weight to 50% by weight of methyl pyrrolidone (N -Methyl-2-Pyrrolidone (NMP)) comprising the step of mixing a binder made of a solution containing,
Method for manufacturing an electrode of an aluminum air battery.
The method of claim 9,
In the step of fixing the mixture to the current collector,
The current collector is a commercial aluminum alloy processed to a thickness of 0.3mm to 3mm is used,
Method for manufacturing an electrode of an aluminum air battery.
The method of claim 9,
Drying the mixture fixed to the current collector,
Comprising a drying time of at least 2 hours at a temperature of 80°C to 130°C.
Method for manufacturing an electrode of an aluminum air battery.
Prepared according to the method of any one of claims 9 to 19,
Electrode of aluminum air battery.

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