KR20230121263A - Manufacturing method for anode electrode material secondary cell using medical waste mask, anode electrode material in secondary cell thereof and secondary cell thereof - Google Patents

Abstract

The present invention relates to a method for manufacturing a negative electrode material for a secondary battery by recycling a medical waste mask, a negative electrode material for a secondary battery using the same, and a secondary battery, and has a one-dimensional structure through recycling of a medical waste mask made of polypropylene (PP) material. It relates to a negative electrode material for a secondary battery synthesized with non-graphitic carbon and a secondary battery.
A method for manufacturing an anode material for a secondary battery by recycling a medical waste mask according to the present invention includes a first step of cutting the waste mask to obtain a piece of the waste mask; A second step of performing a sulfonation reaction by mixing the waste mask pieces and sulfuric acid (H ₂ SO ₄ ); A third step of washing the waste mask pieces subjected to the sulfonation reaction with distilled water (DI water); A fourth step of drying the washed waste mask pieces in a vacuum oven; It is characterized by including; a fifth step of producing a waste mask carbon material (WMC) by carbonization at a temperature of 900 to 1,000 ° C. in a tube furnace in a nitrogen atmosphere.

Description

Manufacturing method of anode material for secondary battery by recycling medical waste mask, anode material for secondary battery and secondary battery using the same }

The present invention relates to a method for manufacturing a negative electrode material for a secondary battery by recycling a medical waste mask, a negative electrode material for a secondary battery using the same, and a secondary battery, and has a one-dimensional structure through recycling of a medical waste mask made of polypropylene (PP) material. It relates to a negative electrode material for a secondary battery synthesized with non-graphitic carbon and a secondary battery.

As the corona pandemic spreads around the world, wearing individual masks is recommended or enforced as a measure to prevent infection. Accordingly, the amount of disposable masks is greatly increasing, and as the amount of masks increases, the amount or amount of waste masks is increasing. Conventionally used waste masks are put into a general trash can, and then collected and collected in a certain amount to be discharged. Therefore, the waste mask discharge treatment is a problem, and the recycling problem of the waste mask needs to be solved.

Meanwhile, worldwide interest in highly efficient energy conversion and storage devices capable of storing electrical energy in the form of chemical energy is increasing. Lithium-ion batteries (LIBs) are a state-of-the-art power source for a variety of modern electronic devices. Among various secondary batteries, LIBs have been regarded as the most promising energy storage systems for next-generation small portable electronic devices including cell phones, laptops, computers, and video cameras because of their excellent energy density and power performance. Lithium-ion batteries can also be used for electric vehicles (HEVs and EVs) because of their high energy density, flexibility, light-weight design and long lifespan. The most common materials used in LIBs are mainly carbon-based anode (cathode) materials (typically graphite), but the demand for lithium batteries with high power, large capacity, and high rate capabilities is increasing, and researchers around the world are now using expensive Currently, new electrode materials that can replace raw materials are being sought. A key urgent task at present is to synthesize carbon materials with high energy and power densities in a low-cost and simple way.

Therefore, the present invention is intended to be applied as an anode material for a lithium ion battery by synthesizing a one-dimensional structure of non-graphitic carbon through recycling of a medical waste mask made of polypropylene (PP) material.

Korean Patent Publication No. 10-2022-0010757

The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for manufacturing an anode material for a lithium ion battery that can reuse a discarded mask.

The technical problems to be solved by the invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below. You will be able to.

A method of manufacturing a negative electrode material for a secondary battery by recycling a medical waste mask according to the present invention,

A first step of cutting the waste mask to obtain a piece of the waste mask;

A second step of performing a sulfonation reaction by mixing the waste mask pieces and sulfuric acid (H ₂ SO ₄ );

A third step of washing the waste mask pieces subjected to the sulfonation reaction with distilled water (DI water);

A fourth step of drying the washed waste mask pieces in a vacuum oven;

A fifth step of producing a waste mask carbon material (WMC) by carbonization at a temperature of 900 to 1,000 ° C. in a tube furnace in a nitrogen atmosphere. .

By means of solving the above problems, the present invention synthesizes one-dimensional non-graphitic carbon using a discarded mask, so it can be applied as an anode material for a lithium ion battery using an environmentally friendly material. can

1 is a schematic view showing a method for manufacturing a negative electrode material for a secondary battery by recycling a waste medical mask of the present invention, a negative electrode material for a secondary battery using the same, and a method for manufacturing a secondary battery.
2 is a scanning electron microscope (SEM) image of a waste mask carbon (WMC) manufactured according to an embodiment of the present invention.
3 is an XRD pattern graph of a waste mask carbon (WMC) manufactured according to an embodiment of the present invention.
4 is a charge and discharge curve of a lithium ion battery using a waste mask carbon material (WMC) manufactured according to an embodiment of the present invention, an initial 3 cycle (0.1C) curve.
5 is a charge and discharge curve of a lithium ion battery using waste mask carbon (WMC) manufactured according to an embodiment of the present invention, and is a 100 cycle (0.5C) curve.
6 is a flow chart of a method for manufacturing an anode material for a secondary battery by recycling a medical waste mask according to the present invention.
7 is a charge and discharge curve of a sodium ion battery using waste mask carbon (WMC) manufactured according to an embodiment of the present invention, an initial 3 cycle (0.1C) curve.
8 is a charge and discharge curve of a sodium ion battery using a waste mask carbon material (WMC) manufactured according to an embodiment of the present invention, and is a 100 cycle (0.5C) curve.
9 is a charge and discharge curve of a potassium ion battery using a waste mask carbon material (WMC) manufactured according to an embodiment of the present invention, an initial 3 cycle (0.1C) curve.
10 is a charge and discharge curve of a potassium ion battery using waste mask carbon (WMC) manufactured according to an embodiment of the present invention, and is a 100 cycle (0.5C) curve.

The terms used in this specification will be briefly described, and the present invention will be described in detail.

The terms used in the present invention have been selected from general terms that are currently widely used as much as possible while considering the functions in the present invention, but these may vary depending on the intention of a person skilled in the art or precedent, the emergence of new technologies, and the like. Therefore, the term used in the present invention should be defined based on the meaning of the term and the overall content of the present invention, not simply the name of the term.

In the entire specification, when a part is said to "include" a certain component, it means that it may further include other components, not excluding other components unless otherwise stated.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

The specific details, including the problem to be solved, the means for solving the problem, and the effect of the invention with respect to the present invention are included in the embodiments and drawings to be described below. Advantages and features of the present invention, and methods for achieving them, will become clear with reference to the embodiments described below in detail in conjunction with the accompanying drawings.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

The present invention is to synthesize one-dimensional non-graphitic carbon through recycling of polypropylene (PP) material for medical waste masks and apply it as a negative electrode material for lithium ion batteries.

6 shows a flowchart of a method for manufacturing a negative electrode material for a secondary battery by recycling a medical waste mask according to the present invention. The present invention, a method for manufacturing a negative electrode material for a secondary battery by recycling a medical waste mask, sulfonates the waste mask in a sulfuric acid solution through a hydrothermal dehydration process, replaces it with a non-volatile material, and then carbonizes it at high temperature ) process to produce non-graphitized carbon.

First, in the first step (S10), a waste mask piece is obtained by cutting the waste mask. More specifically, the waste mask is cut into pieces of 1 g to obtain waste mask pieces.

Next, in the second step (S20), a sulfonation reaction is performed by mixing the waste mask pieces and sulfuric acid (H ₂ SO ₄ ). More specifically, it is preferable to put the waste mask piece and sulfuric acid (H ₂ SO ₄ ) in a Teflon vessel and mix them at 100 to 120 ° C. for 11 to 13 hours to perform sulfonation, More preferably, sulfonation is performed by mixing at 110 ° C. for 12 hours.

Next, in the third step (S30), the waste mask piece subjected to the sulfonation reaction is washed with distilled water (DI water). The waste mask pieces undergoing the sulfonation reaction are washed several times with the distilled water (DI water).

Next, in the fourth step (S40), the washed waste mask pieces are dried in a vacuum oven. More specifically, it is preferable to dry the washed waste mask pieces in a vacuum oven at a temperature of 60 to 80 ° C for 11 to 13 hours, more preferably at 70 ° C for 12 hours.

Next, in the fifth step (S50), carbonization is performed at a temperature of 900 to 1,000 ° C. in a tube furnace in a nitrogen atmosphere to produce a waste mask carbon material (WMC). More specifically, the fifth step (S50) proceeds with carbonization at a temperature of 940 to 960 ° C. for 2 to 4 hours and 5 ° C./min in a tube furnace in a nitrogen atmosphere to activate It is preferable to prepare the material (WMC), and more preferably, carbonization is performed at a temperature of 950° C. for 3 hours and at a rate of 5° C./min.

In addition, the negative electrode material for a lithium ion battery of the present invention preferably includes a waste mask carbon material (WMC) manufactured by the method for manufacturing a negative electrode material for a lithium ion battery by recycling a medical waste mask described above, and also for a secondary battery of the present invention The negative electrode material preferably includes a waste mask carbon material (WMC) manufactured by the method for manufacturing a negative electrode material for a secondary battery by recycling the previously described medical waste mask.

More specifically, it is preferable to mix the slurry with 80 wt% of the waste mask carbon material (WMC), 10 wt% of the conductive agent (acetylene black), and 10 wt% of the binder (PVDF). Although the slurry can be prepared at different mixing ratios, it is preferable to perform the above conditions in order to obtain a uniform and homogeneous slurry without lumps or cracks while maximizing the ratio of the active material. When mixing less than 80 wt% of the waste mask carbon material (WMC), 10 wt% of the conductive agent (acetylene black) and 10 wt% of the binder (PVDF), there may be a problem in that conductivity is lowered, and the waste mask carbon material ( When mixing in excess of 80 wt% WMC, 10 wt% conductive agent (acetylene black), and 10 wt% binder (PVDF), there may be a problem in that the capacity is lowered, so it is preferable to perform the above conditions.

Next, it is coated on copper foil (Cu foil) to a thickness of 140 to 160 μm, and then dried at 70 to 90 ° C for 11 to 13 hours to prepare a negative electrode material for a secondary battery. The prepared negative electrode material for a secondary battery has an active loading density of 2.2 to 2.3 mg/cm 2 , and is compressed to a density of 1 g/cc.

In addition, the secondary battery of the present invention preferably includes a waste mask carbon material (WMC) manufactured by the method for manufacturing a negative electrode material for a secondary battery by recycling the previously described medical waste mask.

Preferably, the secondary battery includes a cathode electrode, a cathode electrode, a separator, and an electrolyte. Preferably, the positive electrode is lithium (Li), the separator is Celgard 2400, and the electrolyte is fluoroethylene carbonate (FEC) and 1.0M LiPF ₆ together. More specifically, a PP/PE/PP (Celgard 2400) multilayer separator and 1M LiPF ₆ EC/DEC (1/1, v/v) + 10 wt% FEC electrolyte were used.

As shown in Example 2 below, the lithium ion battery manufactured by recycling the medical waste mask manufactured by the present invention has a first cycle lithiation and delithiation capacity of 761.9/303.3, respectively, at 0.1 C. It was expressed as mAh/g, and the coulombic efficiency was 39.8%. After the first cycle, the capacity stability was 294.1 mAh/g at 0.1 C and 178.2 mAh/g at 0.5 C, and the charge/discharge curve confirmed that the operating voltage was predominantly less than 1.5 V (FIGS. 4 and 5). did

Hereinafter, the present invention will be described in more detail through examples. Objects, features, and advantages of the present invention will be easily understood through the following examples. The present invention is not limited to the embodiments described herein and may be embodied in other forms. The embodiments introduced here are provided to sufficiently convey the spirit of the present invention to those skilled in the art to which the present invention belongs. Therefore, the present invention should not be limited by the following examples.

Example 1: Fabrication of waste mask carbon (WMC)

Through a hydrothermal dehydration process, the waste mask is sulfonated in a sulfuric acid solution to be substituted with a non-volatile material, and then non-graphitized carbon is produced through a carbonization process at a high temperature.

Cut the waste mask sample (1g) finely and mix it with H ₂ SO ₄ (20 ml) and put it in a Teflon vessel. If it does not mix well, the sample is subjected to the sulfonation process through hydrothermal synthesis (110 ℃, 12 h) in the Magnetic Stirrer. After washing several times with DI water, it is manufactured through a drying process (70 ℃, 12 h) in a vacuum oven. In order to carbonize the sample thus obtained, a heat treatment process (950 ℃, 3 h, 5 ℃/min) is performed in a Tube Furnace in a nitrogen atmosphere to obtain a WMC sample.

As shown in FIG. 2, it can be confirmed through a scanning electron microscope (SEM) image that the solid shape of the material is clear and the end is hard and can be easily broken, waste mask carbon (WMC). can

As shown in FIG. 3, it can be confirmed that the amorphous waste mask carbon material (WMC) was manufactured by looking at the wide peak form at a low angle of the XRD pattern graph.

Example 2: Fabrication of WMC//Li half cell

For the WMC working electrode, a slurry was mixed with waste mask carbon material (WMC): conductive material (acetylene black): binder (PVDF) in a weight ratio of 80: 10: 10, and after applying to Cu foil to a thickness of 150 μm, 80 It was prepared by drying for 12 hours at °C. The WMC working electrode had an active loading density of 2.2~2.3 mg/cm2 and was pressed to a density of 1 g/cc.

Lithium (Li) metal was used for the anode to manufacture the half-cell, and the manufacture of the WMC half-cell was carried out in an argon atmosphere glove box. 1/1, v/v) + 10 wt% FEC electrolyte was used.

The charge/discharge test was conducted, and the WMC//Li half cell was subjected to 0.1C, 3 cycles and then 0.5C, 100 cycles in the voltage range of 0.01-3.0 V.

As shown in FIG. 4, WMC//Li had a lithiation/delithiation capacity of 761.9/303.3 mAh/g in the first cycle at 0.1 C, respectively, and a coulombic efficiency of 39.8%.

As shown in FIG. 5, after the first 3 cycles at 0.1C in FIG. 4, the 4th consecutive cycle at 0.5C showed a discharge capacity of 238.4 mAh/g and a discharge capacity stability of 178.2 mAh/g up to 100 cycles thereafter, Through the charge/discharge curve, it was confirmed that the operating voltage appeared predominantly at less than 1.5 V.

Example 3: Fabrication of WMC//Na half cell

As in Example 2, the WMC working electrode was mixed with a slurry of waste mask carbon material (WMC): conductive material (acetylene black): binder (PVDF) in a weight ratio of 80: 10: 10, and Cu foil with a thickness of 150 μm. After applying to a thickness, it was manufactured by drying at 80 ° C for 12 hours. The WMC working electrode had an active loading density of 2.2~2.3 mg/cm2 and was pressed to a density of 1 g/cc.

To manufacture the half cell, sodium (Na) metal was used as the anode, and the manufacture of the WMC half cell was carried out in an argon atmosphere glove box, and a glass fiber filter (Whatman/GF/A) separator and 1M NaPF6 DEGDME (1 /1, v/v) electrolyte solution was used.

The charge/discharge test was conducted, and the WMC//Na half-cell was subjected to 0.1C, 3 cycles and then 0.5C, 100 cycles in the voltage range of 0.01-2.5 V.

As shown in FIG. 7, WMC // Na showed a sodiation / desodiation capacity of 231.3 / 135.5 mAh / g in the first cycle at 0.1 C, respectively, and a coulombic efficiency of 41.4%, but 99 in the second and third cycles. A stable value of % or higher was indicated.

As shown in FIG. 8, after the first 3 cycles at 0.1 C in FIG. 7, the discharge capacity of 125.4 mAh/g in the 4 consecutive cycles at 0.5 C and the discharge capacity of 71.4 mAh/g up to 100 cycles thereafter continuously decreased. showed This is judged to be instability that appears because the size of Na ions is larger than that of Li ions when a relatively high current density (C-rate) is applied. It is believed that the performance can be improved by changing the type of electrolyte.

Example 4: Fabrication of WMC//K half cell

As in Example 2, the WMC working electrode was mixed with a slurry of waste mask carbon material (WMC): conductive material (acetylene black): binder (PVDF) in a weight ratio of 80: 10: 10, and Cu foil with a thickness of 150 μm. After applying to a thickness, it was manufactured by drying at 80 ° C for 12 hours. The WMC working electrode had an active loading density of 2.2~2.3 mg/cm2 and was pressed to a density of 1 g/cc.

To manufacture the half-cell, potassium (K) metal was used for the anode, and the manufacture of the WMC half-cell was carried out in an argon atmosphere glove box, and a glass fiber filter (Whatman/GF/A) separator and 0.8M KFSI + EC /DEC (1/1, v/v) electrolyte was used.

The charge/discharge test was carried out, and the WMC//K half cell was subjected to 0.1C, 3 cycles and then 0.5C, 100 cycles in the voltage range of 0.01-3.0 V.

As shown in FIG. 9, WMC//K showed a potassiation / depotassiation capacity of the first cycle at 0.1C of 501.2 / 95.5 mAh / g, respectively, and the coulombic efficiency was very low at 19.1%, but the second and third Cycles showed stable values of 95% or more.

As shown in FIG. 10, stability was maintained with a discharge capacity of 57.9 mAh/g in the 4th consecutive cycle at 0.5C after the first 3 cycles at 0.1C in FIG. 7 and a discharge capacity of 41.2 mAh/g up to 100 cycles thereafter. . Unlike Na, cycle stability was maintained even though the specific capacity was low due to the large ionic radius. This is because the solid-electrolyte interphase (SEI) layer formed on the surface of the sample during the initial discharge was thicker in the case of Li than in the case of Na, and it was determined that K ions were stably entering and exiting under the prepared conditions.

By means of solving the above problems, the present invention synthesizes one-dimensional non-graphitic carbon using a discarded mask, so it can be applied as an anode material for a lithium ion battery using an environmentally friendly material. can

As such, it will be understood that the technical configuration of the present invention described above can be implemented in other specific forms without changing the technical spirit or essential features of the present invention by those skilled in the art to which the present invention pertains.

Therefore, the embodiments described above should be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the claims to be described later rather than the detailed description, and the meaning and scope of the claims and their All changes or modified forms derived from equivalent concepts should be construed as being included in the scope of the present invention.

S10. The first step to obtain waste mask pieces by cutting the waste mask
S20. A second step of performing a sulfonation reaction by mixing the waste mask pieces and sulfuric acid (H ₂ SO ₄ )
S30. A third step of washing the waste mask pieces subjected to the sulfonation reaction with distilled water (DI water)
S40. A fourth step of drying the washed waste mask pieces in a vacuum oven
S50. The fifth step of producing waste mask carbon material (WMC) by carbonization at a temperature of 900 to 1,000 ° C in a tube furnace in a nitrogen atmosphere

Claims (5)

A first step of cutting the waste mask to obtain a piece of the waste mask;
A second step of performing a sulfonation reaction by mixing the waste mask pieces and sulfuric acid (H ₂ SO ₄ );
A third step of washing the waste mask pieces subjected to the sulfonation reaction with distilled water (DI water);
A fourth step of drying the washed waste mask pieces in a vacuum oven;
A fifth step of producing a waste mask carbon material (WMC) by carbonization at a temperature of 900 to 1,000 ° C. in a tube furnace in a nitrogen atmosphere; A method for manufacturing a negative electrode material for a recycled secondary battery.
Waste mask carbon material (WMC) prepared by mixing waste mask pieces and sulfuric acid (H ₂ SO ₄ ) to perform sulfonation, and then carbonization at a temperature of 900 to 1,000 ° C. include,
A negative electrode material for a secondary battery, characterized in that it is mixed with 80 wt% of the waste mask carbon material (WMC), 10 wt% of a conductive agent (acetylene black), and 10 wt% of a binder (PVDF).
According to claim 2,
The anode material for the secondary battery,
An anode material for a secondary battery, characterized in that the active loading density is 2.2 to 2.3 mg/cm 2 .
In the secondary battery composed of a positive electrode, a negative electrode, a separator and an electrolyte,
Waste mask carbon material (WMC) prepared by mixing waste mask pieces and sulfuric acid (H ₂ SO ₄ ) to perform sulfonation, and then carbonization at a temperature of 900 to 1,000 ° C. A secondary battery, characterized in that using the negative electrode material manufactured including as a negative electrode.
According to claim 1,
The positive electrode is lithium (Li),
The separator is Celgard 2400,
The electrolyte solution is a secondary battery, characterized in that fluoroethylene carbonate (FEC) and 1.0M LiPF ₆ are used together.