Method for preparing porous carbon electrode material by taking waste medical mask as raw material

Abstract

The invention relates to the technical field of porous carbon electrode materials, in particular to a preparation method of a porous carbon electrode material with a waste medical mask as a raw material, comprising the following steps: S1, soaking the waste medical mask in concentrated sulfuric acid for sulfonation reaction; and filtering, washing and drying to obtain the sulfonated mask particles. And S2, mixing the sulfonated mask particles with solid alkali, and carrying out mechanical ball milling activation treatment to obtain the activated mask derived porous carbon material. S3, performing high-temperature calcination on the mask derived porous carbon material, and then adding hydrochloric acid to remove residual solid alkali; and alternately washing with ionized water and ethanol, and drying to obtain the porous carbon electrode material. The preparation method has the advantages that agglomeration of material particles is effectively avoided through ball milling, and the dispersity and the specific surface area of the material are improved. Through the synergistic effect of mechanical ball milling and a potassium hydroxide activating agent, a hierarchical pore structure is accurately constructed in a carbon skeleton of polypropylene, and an ion transmission path is optimized.

Description

Technical Field

[0001] The present invention relates to the technical field of porous carbon electrode materials, and in particular to a method for preparing a porous carbon electrode material using discarded medical masks as raw materials. Background Art

[0002] With the surge in the use of disposable medical masks worldwide, the disposal of discarded masks has become a serious environmental challenge. Disposable masks are primarily composed of polypropylene (PP) meltblown nonwoven fabric. Its non-biodegradable nature poses a secondary pollution risk through traditional landfill or incineration, necessitating the development of efficient, high-value-added resource utilization technologies. Simultaneously, demand for high-performance carbon electrode materials is growing in energy storage applications (such as supercapacitors and fuel cells), but their preparation often relies on high-cost precursors (such as petroleum-based polymers or biomass) and involves complex processes and high energy consumption. The performance of porous carbon materials lies at the heart of their pore structure (e.g., micropore, mesopore, and macropore distribution) and surface chemical properties (e.g., functional groups, conductivity). Existing methods for preparing carbon materials from waste polymers primarily include direct carbonization, chemical activation (e.g., with KOH and H3PO4), and template methods.

[0003] The Chinese patent application, CN112158823A, published on January 1, 2021, is titled "A Method for Preparing Porous Carbon Gel Materials from Discarded Masks." It discloses a three-step process for converting masks into porous carbon gel materials via low-temperature sterilization, pre-carbonization, and high-temperature carbonization. While this method simplifies the process, it fails to optimize the pore structure for electrode applications. The resulting material has a low specific surface area and lacks the introduction of functional components, resulting in insufficient electrochemical performance.

[0004] The Chinese patent application, CN115910619A, published on December 29, 2022, is titled "A Mask-Based Sulfur-Rich Porous Carbon Material, Its Preparation Method, and Application." The invention utilizes a sulfonation crosslinking strategy to enhance the thermal stability of polypropylene (PP) molecular chains, followed by NaOH activation to produce high-surface-area activated carbon. Using the mask's interlayer as a carbon source, a metal polyphenol network is constructed by combining bayberry tannins with metal compounds. The resulting aerogel carbon electrode is freeze-dried and pyrolyzed at high temperatures. This material exhibits an oxygen reduction onset potential of 1.08 V, but the process requires multiple steps in an organic solvent (xylene), which is costly. Furthermore, the metal coordination process is sensitive to pH and temperature, making large-scale production difficult.

[0005] While existing technologies have made progress in the field of mask-derived carbon materials, the following challenges remain: Extensive pore structure control and a lack of multi-level pore coordination limit ion transport kinetics. Functionalization methods are limited, failing to integrate the advantages of physical activation and chemical modification, making it difficult to achieve high specific surface area and specific capacitance. Summary of the Invention

[0006] In view of this, the present invention aims to provide a method for preparing porous carbon electrode materials using discarded medical masks as raw materials. Through the synergistic effect of mechanical ball milling and potassium hydroxide activator, a multi-level pore structure is precisely constructed in the carbon skeleton of polypropylene, and the ion transmission path is optimized, thereby enabling it to have extremely high electrochemical performance when used as a supercapacitor electrode material.

[0007] To achieve the above object, the technical solution created by the present invention is implemented as follows: a method for preparing a porous carbon electrode material using discarded medical masks as raw materials, comprising the following steps: S1: Soak the discarded medical masks in concentrated sulfuric acid to carry out sulfonation reaction; after the reaction is completed, filter and wash to remove excess concentrated sulfuric acid; finally, dry them to obtain sulfonated mask particles.

[0008] S2: The sulfonated mask particles are mixed with a solid base and subjected to mechanical ball milling activation treatment to obtain an activated mask-derived porous carbon material.

[0009] S3: The mask-derived porous carbon material is calcined at high temperature under the protection of inert gas, and hydrochloric acid is added after high-temperature calcination to remove the residual solid alkali; ion water and ethanol are used to wash the material alternately multiple times, and finally the washed material is dried to obtain a porous carbon electrode material.

[0010] Furthermore, in step S1, the mass concentration of concentrated sulfuric acid is 96% to 98%; the discarded medical masks are soaked in concentrated sulfuric acid for 8 minutes to 15 minutes.

[0011] Furthermore, in step S1, the ratio of the mass of the discarded medical masks to the volume of concentrated sulfuric acid is 1:20 to 1:6; wherein the mass unit of the discarded medical masks is gram, and the volume unit of the concentrated sulfuric acid is milliliter.

[0012] Furthermore, in step S1, the temperature of the sulfonation reaction is 150° C. to 180° C.; and the reaction time is 10 hours to 15 hours.

[0013] Furthermore, the activation process in step S2 includes the following steps: S21: Add sulfonated mask particles and sodium hydroxide into the ball mill according to a preset mass ratio.

[0014] S22: adding a preset mass of stainless steel balls into the ball mill; then, the ball mill performs ball milling at a preset speed per minute and for a preset time to obtain a mask-derived porous carbon material.

[0015] Furthermore, the rotation speed of the ball mill is 600 rpm to 800 rpm, and the ball milling treatment time is 24 hours to 48 hours.

[0016] Furthermore, in step S2, the solid base is potassium hydroxide.

[0017] Furthermore, in step S3, the high-temperature calcination is carried out by heating the mixture to 600°C to 750°C at a rate of 3°C / min to 6°C / min under the protection of an inert gas, and then calcining the mixture for 1.5 hours to 3 hours.

[0018] Furthermore, in step S3, the drying temperature is 55° C. to 70° C., and the drying time is 10 hours to 24 hours.

[0019] Compared with the prior art, the present invention can achieve the following beneficial effects: 1) Concentrated sulfuric acid, as a strong acid and strong oxidant, destroys the hydrocarbon chain structure of polypropylene through sulfonation reaction, introduces sulfonic acid groups, improves the thermal stability of the material, makes it easier to react with KOH, and improves activation efficiency.

[0020] 2) The rotation of the stainless steel ball mill ensures thorough mixing of the sulfonated mask particles and potassium hydroxide. Simultaneously, the grinding and shearing action between the stainless steel balls effectively prevents particle agglomeration, significantly improving the material's dispersibility and specific surface area. The combination of ball milling and sulfonation processes enables efficient pretreatment of the materials (sulfonated mask particles and potassium hydroxide). The synergistic effect of mechanical ball milling and potassium hydroxide activator precisely constructs a hierarchical pore structure within the polypropylene carbon backbone, optimizing ion transport pathways.

[0021] 3) The porous carbon electrode material prepared by this invention exhibits excellent electrochemical performance. At a current density of 1 A / g, its specific capacitance reaches 352.6 F / g, and after 10,000 cycles, the capacitance retention remains above 99%. Furthermore, when this material is assembled into a symmetrical supercapacitor device, the device's specific capacitance reaches 122.6 F / g at a current density of 1 A / g, and the capacity retention remains at 82.6% after 10,000 cycles. These performance indicators significantly outperform existing technologies.

[0022] 4) The material's high specific surface area, excellent conductivity, and good catalytic activity make it ideal for use as a supercapacitor electrode material, meeting the demands of high-performance energy storage. Furthermore, the material's stable performance, excellent cycle life, and rate capability make it suitable for large-scale commercial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which constitute part of the present invention, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings: Figure 1This is a flow chart of a method for preparing a porous carbon electrode material using discarded medical masks as raw materials according to an embodiment of the present invention; Figure 2 is an XRD pattern (X-ray diffraction pattern) of sulfonated mask particles, mask-derived porous carbon materials, and porous carbon electrode materials provided according to embodiments of the present invention; Figure 3 This is a Raman spectrum of the sulfonated mask particles and porous carbon electrode materials provided by an embodiment of the present invention; Figure 4 TEM (transmission electron microscope) and SEM (scanning electron microscope) images of the porous carbon material provided by an embodiment of the present invention after calcination at 700° C. Figure 5 1. (a) Cyclic voltammetry curve and (b) charge-discharge curve of a three-electrode system of a porous carbon electrode material according to an embodiment of the present invention; Figure 6 2. It is a graph showing the long cycle performance of a three-electrode system of a porous carbon electrode material according to an embodiment of the present invention; Figure 7 1. (a) Cyclic voltammetry curve and (b) charge-discharge curve of a two-electrode system of a porous carbon electrode material according to an embodiment of the present invention; Figure 8 This is a long cycle performance diagram of a dual-electrode system of a porous carbon electrode material provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0025] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0026] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, features defined as "first", "second" and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0027] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0028] The present invention will be described in detail below with reference to the embodiments.

[0029] like Figures 1 to 8 As shown, an embodiment of the present invention provides a method for preparing a porous carbon electrode material using discarded medical masks as raw materials, comprising the following steps: S1: Soak the discarded medical masks in concentrated sulfuric acid to carry out sulfonation reaction; after the reaction is completed, filter and wash to remove excess concentrated sulfuric acid; finally, dry them to obtain sulfonated mask particles.

[0030] S2: The sulfonated mask particles are mixed with a solid base and subjected to mechanical ball milling activation treatment to obtain an activated mask-derived porous carbon material.

[0031] S3: The mask-derived porous carbon material is calcined at high temperature under the protection of inert gas, and hydrochloric acid is added after high-temperature calcination to remove the residual solid alkali; ion water and ethanol are used to wash the material alternately multiple times, and finally the washed material is dried to obtain a porous carbon electrode material.

[0032] Furthermore, in step S1, the mass concentration of concentrated sulfuric acid is 96% to 98%; the discarded medical masks are soaked in concentrated sulfuric acid for 8 minutes to 15 minutes.

[0033] Furthermore, in step S1, the ratio of the mass of the discarded medical masks to the volume of concentrated sulfuric acid is 1:20 to 1:6; wherein the mass unit of the discarded medical masks is gram, and the volume unit of the concentrated sulfuric acid is milliliter.

[0034] Furthermore, in step S1, the temperature of the sulfonation reaction is 150° C. to 180° C.; and the reaction time is 10 hours to 15 hours.

[0035] Furthermore, the activation process in step S2 includes the following steps: S21: Add sulfonated mask particles and sodium hydroxide into the ball mill according to a preset mass ratio.

[0036] S22: adding a preset mass of stainless steel balls into the ball mill; then, the ball mill performs ball milling at a preset speed per minute and for a preset time to obtain a mask-derived porous carbon material.

[0037] Furthermore, the rotation speed of the ball mill is 600 rpm to 800 rpm, and the ball milling treatment time is 24 hours to 48 hours.

[0038] Furthermore, in step S2, the solid base is potassium hydroxide.

[0039] Furthermore, in step S3, the high-temperature calcination is carried out by heating the mixture to 600°C to 750°C at a rate of 3°C / min to 6°C / min under the protection of an inert gas, and then calcining the mixture for 1.5 hours to 3 hours.

[0040] Furthermore, in step S3, the drying temperature is 55° C. to 70° C., and the drying time is 10 hours to 24 hours.

[0041] The present invention is combined with Figures 1-8 A method for preparing a porous carbon electrode material using discarded medical masks as raw materials provided by the present invention is described with a specific embodiment.

[0042] S1: Sulfonation treatment: S11: Take 10 g of discarded disposable polypropylene medical mask particles, add them to 200 ml of 98% H2SO4, and soak them for 10 minutes.

[0043] Concentrated sulfuric acid, as a strong acid and strong oxidant, destroys the hydrocarbon chain structure of polypropylene through sulfonation reaction, introduces sulfonic acid groups, improves the thermal stability of the material, makes it easier to react with KOH, and improves activation efficiency.

[0044] S12: Transfer the soaked mask particles to three 100 ml polytetrafluoroethylene (PTFE) reactors. Each reactor is filled with approximately 65 ml of the mixture of concentrated sulfuric acid and disposable polypropylene medical mask particles from step S11, and the reactors are sealed. Due to the volume limitations of the PTFE reactors, the mixture of concentrated sulfuric acid and mask particles from step S11 must be divided among the three reactors for processing.

[0045] S13: placing the polytetrafluoroethylene reactor in a forced air drying oven for sulfonation reaction at a temperature of 160° C. for 12 hours.

[0046] The blast drying oven is a purchased part produced by Shanghai Yilin Scientific Instrument Co., Ltd., model DHG-9055A.

[0047] S14: After the reaction is completed, the polytetrafluoroethylene reactor is taken out and the black product therein is filtered out.

[0048] S15: Wash the black product with deionized water at least three times to remove residual sulfuric acid.

[0049] S16: Dry at 60°C for 12 hours to obtain black sulfonated mask particles.

[0050] The polytetrafluoroethylene reactor is a purchased part produced by Shanghai Fuding Technology Co., Ltd., model FDHR-100.

[0051] S2: Activate the sulfonated mask particles using mechanical ball milling: S21: Weigh 15 g of sulfonated mask particles and potassium hydroxide (KOH) at a 2:1 ratio (preset mass ratio). This includes 10 g of sulfonated mask particles and 5 g of potassium hydroxide. Place the weighed materials into a stainless steel ball mill.

[0052] S22: Add 10 mm diameter stainless steel balls. The mass ratio of stainless steel balls to the material (sulfonated mask particles and potassium hydroxide) is 20:1, resulting in a total mass of 300 g of stainless steel balls. Rotate the stainless steel ball mill at 600 rpm (preset speed) for 24 hours (preset time). After milling, 13 g to 14.5 g of activated mask-derived porous carbon material is obtained.

[0053] The rotation of the stainless steel ball mill ensures thorough mixing of the sulfonated mask particles and potassium hydroxide. Simultaneously, the grinding and shearing action between the stainless steel balls effectively prevents particle agglomeration, significantly improving the dispersion and specific surface area of the material. The combination of ball milling and sulfonation processes enables efficient pretreatment of the materials (sulfonated mask particles and potassium hydroxide). The synergistic effect of mechanical ball milling and potassium hydroxide activator precisely constructs a hierarchical pore structure within the polypropylene carbon backbone, optimizing ion transport pathways.

[0054] The stainless steel ball mill is a purchased part produced by Changsha Miqi Instrument Equipment Co., Ltd., model YXQM-1L.

[0055] S3: High temperature calcination: S31: Pour 15 g of mask-derived porous carbon material into a porcelain boat.

[0056] S32: Under the protection of inert gas (N2), place the porcelain boat in a tube furnace, heat it to 700℃ at a heating rate of 5℃ / min, and keep calcining at 700℃ for 2 hours. High-temperature calcination under N2 protection, combined with ball milling activation treatment, further optimizes the pore structure and surface chemical properties of the carbon material. Figure 4 As shown, the TEM image (transmission electron microscope image) and SEM image (scanning electron microscope image) of the mask-derived porous carbon material after calcination at 700°C.

[0057] The tubular furnace is a purchased part, produced by Hefei Kejing Material Technology Co., Ltd., model OTF-1200X.

[0058] The porcelain boat is a purchased part, produced by Lianyungang Haibo Technology Co., Ltd., and the model is OEM.

[0059] S33: After the calcination is completed, the calcined product is immersed in a 1 mol / L hydrochloric acid solution to remove residual KOH.

[0060] S34: The product treated in step S33 is washed alternately with deionized water and ethanol at least three times to remove surface impurities and residual acid.

[0061] S35: Dry the washed product at 60° C. for 12 hours to finally obtain a porous carbon electrode material.

[0062] The reaction equation in step S3 is as follows: (1) High-temperature decomposition of KOH: 2KOH → K2O + H2O↑.

[0063] (2) Direct reaction of KOH with carbon: 6KOH + 2 C →K2CO3 + 3H2↑.

[0064] (3) Further reaction of intermediate products with carbon: K2O + C → 2 K + CO↑.

[0065] (4) Pickling to remove residual KOH and its products: K2CO3+ 2 HCl → 2 KCl+CO2↑ + H2O.

[0066] like Figure 2 The XRD patterns shown in Figure 1 demonstrate the changes in the crystal structure of sulfonated mask particles, porous carbon materials, and porous carbon electrode materials under different treatment conditions. The figure includes the XRD patterns of the sulfonated mask particles, porous carbon materials, and porous carbon electrode materials, and compares them with standard XRD patterns of polypropylene (PDF#50-2397) and potassium hydroxide (KOH, PDF#15-0890). By comparing the XRD patterns of the samples with the standard patterns, it is possible to analyze the material composition, modification effects, and the formation of the porous structure.

[0067] like Figure 3 As shown in the figure, the Raman spectrum characteristics of sulfonated mask particles and porous carbon materials at different treatment temperatures are shown. As can be seen from the figure, with the increase of treatment temperature, the intensity ratio of the D peak and the G peak of the carbon in the sulfonated mask particles and porous carbon materials (I D / I G This indicates that the disorder and defect density of the material gradually decrease, and the degree of graphitization gradually increases.

[0068] S4: Material testing of porous carbon electrode materials: 50 mg of porous carbon electrode material, 10 mg of acetylene black, and 10 mg of binder (polytetrafluoroethylene) were mixed in a mass ratio of 5:1:1, for a total mass of 70 mg. The mixture was added to 3 ml of anhydrous ethanol to form a mixed solution. The mixed solution was placed in the container of an ultrasonic device set to 400 W power and 40 kHz frequency. The mixture was sonicated for 40 minutes to produce a uniformly dispersed black suspension. After sonication, the suspension was transferred to a forced air drying oven and dried at 60°C for 12 hours to form a paste. After cooling to room temperature, the paste was evenly coated on a 1 cm × 1 cm nickel foam substrate and compacted under a pressure of 15 MPa to obtain a working electrode.

[0069] The ultrasonic cleaning machine is a purchased part, produced by Hangzhou Farrant Ultrasonic Technology Co., Ltd., model FRQ-1020.

[0070] The electrochemical performance of the electrodes was evaluated using a CHI 660E workstation (manufactured by Shanghai Chenhua Instrument Co., Ltd.), including cyclic voltammetry (CV), charge-discharge (GCD) test, and electrochemical impedance spectroscopy (EIS).

[0071] Three-electrode system test, such as Figure 5 、 Figure 6 As shown: A potassium hydroxide solution containing 6 moles per liter of solution was used as the electrolyte, nickel foam loaded with active substances was used as the working electrode, platinum mesh was used as the counter electrode, and Hg / HgO was used as the reference electrode.

[0072] The test voltage window is 0 V to 1 V. The scan rate of the CV test is 5 mV s -1 ~100 mV s -1 The GCD test was carried out at a current density of 1A g -1 ~10 A g -1 The frequency range of EIS measurements was 100 kHz to 10 mHz with a sinusoidal amplitude of 5 mV.

[0073] The specific capacitance calculation formula is: ; Among them, C m is the specific capacitance, I is the discharge current, △t is the discharge time, m is the mass of the electrode material, and △V is the potential window.

[0074] In order to further evaluate the performance of electrode materials in practical applications, a dual-electrode system test was also conducted. Figure 7 、 Figure 8 shown.

[0075] The voltage window of the two-electrode test was 0 V–1.4 V. A CT-4008Tn-50 mA cycling test system (NEWARE Electronics Co., Ltd.) was used to assemble CR2032 button cells to evaluate the long-term cycling stability of the two-electrode device.

[0076] The porous carbon electrode material prepared by this invention exhibits excellent electrochemical performance. At a current density of 1 A / g, its specific capacitance reaches 352.6 F / g, and after 10,000 cycles, the capacitance retention rate remains as high as over 99%. Furthermore, when this material is assembled into a symmetrical supercapacitor device, the device's specific capacitance reaches 122.6 F / g at a current density of 1 A / g, and the capacity retention rate remains at 82.6% after 10,000 cycles. These performance indicators significantly surpass existing technologies.

[0077] The material's high specific surface area, excellent conductivity, and good catalytic activity make it ideal for use as a supercapacitor electrode material, meeting the demands of high-performance energy storage. Furthermore, the material's stable performance, coupled with its excellent cycle life and rate capability, makes it suitable for large-scale commercial applications.

[0078] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A method for preparing a porous carbon electrode material using discarded medical masks as raw materials, characterized in that: The following steps are involved: S1: Soaking discarded medical masks in concentrated sulfuric acid to carry out a sulfonation reaction; after the reaction is completed, filtering and washing to remove excess concentrated sulfuric acid; finally, drying to obtain sulfonated mask particles; S2: mixing the sulfonated mask particles with a solid base and performing a mechanical ball milling activation treatment to obtain an activated mask-derived porous carbon material; S3: The mask-derived porous carbon material is subjected to high-temperature calcination under the protection of an inert gas, and hydrochloric acid is added after high-temperature calcination to remove the residual solid alkali; ionized water and ethanol are used to wash the material alternately for at least three times, and finally the washed material is dried to obtain a porous carbon electrode material.

2. The method for preparing a porous carbon electrode material using discarded medical masks as raw materials according to claim 1, characterized in that: In step S1, the concentration of the concentrated sulfuric acid is 96% to 98%; the discarded medical masks are soaked in the concentrated sulfuric acid for 8 minutes to 15 minutes.

3. The method for preparing a porous carbon electrode material using discarded medical masks as raw materials according to claim 1, characterized in that: In step S1, the ratio of the mass of the discarded medical masks to the volume of concentrated sulfuric acid is 1:20 to 1:6; wherein the mass unit of the discarded medical masks is gram, and the volume unit of the concentrated sulfuric acid is milliliter.

4. The method for preparing a porous carbon electrode material using discarded medical masks as raw materials according to claim 1, characterized in that: In step S1, the temperature of the sulfonation reaction is 150° C. to 180° C.; and the reaction time is 10 hours to 15 hours.

5. The method for preparing a porous carbon electrode material using discarded medical masks as raw materials according to claim 1, characterized in that: The activation process of step S2 includes the following steps: S21: adding the sulfonated mask particles and solid alkali into a ball mill according to a preset mass ratio; S22: Stainless steel balls are added to the ball mill; then, the ball mill is subjected to ball milling treatment at a preset speed and for a preset time to obtain a mask-derived porous carbon material.

6. The method for preparing a porous carbon electrode material using discarded medical masks as raw materials according to claim 5, characterized in that: The ball milling jar has a rotation speed of 600 rpm to 800 rpm, and the ball milling treatment time is 24 hours to 48 hours.

7. The method for preparing a porous carbon electrode material using discarded medical masks as raw materials according to claim 1 or claim 5, characterized in that: The solid base is potassium hydroxide.

8. The method for preparing a porous carbon electrode material using discarded medical masks as raw materials according to claim 1, characterized in that: In step S3 , the high-temperature calcination is carried out by heating the material to 600° C. to 750° C. at a rate of 3° C. / min to 6° C. / min under inert gas protection, and then calcining the material for 1.5 hours to 3 hours.

9. The method for preparing a porous carbon electrode material using discarded medical masks as raw materials according to claim 1, characterized in that: In step S3 , the drying temperature is 55° C. to 70° C., and the drying time is 10 hours to 24 hours.

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