Tar residue-based porous carbon electrode material, preparation method and supercapacitor electrode
Patent Information
- Application Number
- CN202610986643.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-03
- Publication Date
- 2026-09-04
AI Technical Summary
然而，采用单一碳源直接制备的焦油渣基碳材料通常存在孔结构不发达、比表面积有限、活性位点不足以及电化学性能较差等问题，难以满足高性能储能器件对电极材料的要求
[0025] The beneficial effects of this invention are that it uses tar residue as a carbon source, combined with acetone and carbon disulfide Soxhlet extraction to extract soluble components, effectively removing impurities and improving the uniformity of the carbon source; simultaneously, it introduces MOF-based precursor materials and potassium hydroxide for synergistic effects, completing structural regulation and pore construction simultaneously during high-temperature carbonization, thus constructing a well-developed porous structure. In-situ doping is achieved using melamine as a nitrogen source, simplifying the traditional multi-step doping process, improving material preparation efficiency, and providing a feasible path for low-cost, high-value-added utilization of tar residue.
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Figure CN122685047A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of solid waste preparation of porous carbon materials, and particularly to a tar residue-based porous carbon electrode material, its preparation method, and a supercapacitor electrode. Background Technology
[0002] With global population growth and the accelerating pace of urbanization and industrialization, the amount of solid waste generated continues to increase. Its harmless disposal and resource utilization have become important research directions in the fields of environmental protection and sustainable energy development. Coal tar residue is a typical organic solid waste generated during coal chemical production. Rich in aromatic structures, fixed carbon, and oxygen-containing functional groups, it possesses high potential for carbon resource utilization. However, currently, coal tar residue is mainly treated through incineration or landfill, which not only wastes resources but also potentially causes environmental pollution. Therefore, converting coal tar residue into high-value-added carbon materials and realizing its resource utilization has significant economic and environmental value.
[0003] In recent years, porous carbon materials have been widely used in the field of supercapacitor electrode materials due to their high specific surface area, good conductivity, and excellent electrochemical stability. However, tar-based carbon materials prepared directly from a single carbon source often suffer from problems such as underdeveloped pore structure, limited specific surface area, insufficient active sites, and poor electrochemical performance, making it difficult to meet the requirements of high-performance energy storage devices for electrode materials. Although methods such as chemical activation, heteroatom doping, and template-assisted construction can improve material properties to some extent, they still have drawbacks such as complex processes, high costs, or limited ability to control pore structure.
[0004] Therefore, there is an urgent need to develop a simple, low-cost, highly controllable, and large-scale application method for preparing porous carbon electrode materials based on tar residue, so as to achieve high-value utilization of tar residue and obtain supercapacitor electrode materials with high specific surface area, rich pore structure and excellent electrochemical performance. Summary of the Invention
[0005] This invention discloses a tar residue-based porous carbon electrode material, its preparation method, and a supercapacitor electrode. The tar residue-based porous carbon electrode material prepared by this invention has advantages such as high specific surface area and cycle stability, as well as high specific capacitance and ideal pseudocapacitance.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] A method for preparing a porous carbon electrode material based on tar residue specifically includes the following steps:
[0008] S1. The tar residue sample was subjected to Soxhlet extraction using a mixed solvent of acetone and carbon disulfide to obtain tar residue solubles, which were used as a carbon source.
[0009] S2. After mixing the carbon source obtained in step S1 with melamine in a certain proportion, KOH solution is added, and the mixture is stirred and the solvent is removed under water bath conditions to obtain a precursor. Then MOF-based precursor material is added and mixed evenly. The mixture is placed in a horizontal tube furnace and reacted under high temperature and N2 conditions. After cooling to room temperature, tar residue-based porous carbon is obtained.
[0010] S3. The tar residue-based porous carbon obtained in step S2 is placed in an acid solution and magnetically stirred. It is then washed with deionized water and ethanol until neutral, and then dried to obtain the tar residue-based porous carbon electrode material.
[0011] In a further step S1, the volume ratio of acetone to carbon disulfide is 1:(0.8~1.2); the solid-liquid ratio of the tar residue sample to the mixed solvent is 1:(20~60) g•mL. -1 Soxhlet extraction time is 12-48 hours.
[0012] More preferably, the volume ratio of acetone to carbon disulfide is 1:1; the solid-liquid ratio of the tar residue sample to the mixed solvent is 1:40 g•mL-1; and the Soxhlet extraction time is 24 h.
[0013] Further, in step S2, the MOF-based precursor material is selected from ZIF-67 or core-shell ZIF-67@mZrO2 composite material, and the mass ratio of carbon source to MOF-based precursor material is 8: (0.5~1.5).
[0014] More preferably, the mass ratio of carbon source to MOF-based precursor material is 8:1.
[0015] Further, in step S2, the mass ratio of melamine, carbon source and KOH is (0.2~0.3):1:(0.8~1.2).
[0016] More preferably, the mass ratio of melamine, carbon source and KOH is 0.25:1:1.
[0017] Furthermore, in step S2, the reaction conditions are controlled as follows: temperature 600~800℃, time 1~3h, and N2 flow rate 180~220 mL•min. -1 .
[0018] More preferably, the high temperature is 700°C, the time is 2 h, and the N2 flow rate is 200 mL•min. -1 .
[0019] Furthermore, the acid solution in step S3 is a hydrochloric acid solution with a mass concentration of 0.8~1.2 mol·L⁻¹. -1 The drying temperature is 70~90℃, and the drying time is 20~28h.
[0020] More preferably, the mass concentration of the acid solution is 1 mol·L⁻¹. -1 The drying temperature is 80℃ and the drying time is 24 hours.
[0021] Secondly, the present invention also discloses a tar residue-based porous carbon electrode material prepared by the above-described preparation method.
[0022] Thirdly, the present invention also discloses a supercapacitor electrode made using the above-mentioned tar residue-based porous carbon electrode material.
[0023] This invention also discloses a method for preparing a supercapacitor electrode, comprising uniformly mixing a conductive agent, a binder, and a tar-based porous carbon electrode material in a mass ratio of 1:(0.5~1.5):(7~9), adding a solvent, and mixing the mixture into a slurry. The slurry is then coated onto nickel foam and dried, with an area of 0.8~1.2 cm². 2 The electrode of the supercapacitor is obtained by compacting it under a pressure of 10~40MPa.
[0024] Further, the conductive agent is acetylene black; the binder includes one or more of polytetrafluoroethylene, polyacrylamide, polybutadiene, polyvinylpyrrolidone, polyethylene oxide, fluororubber, and polyvinyl alcohol; the solvent includes one or more of alcohols, water, ethyl acetate, dimethyl carbonate, methyl propionate, and diethyl carbonate.
[0025] The beneficial effects of this invention are that it uses tar residue as a carbon source, combined with acetone and carbon disulfide Soxhlet extraction to extract soluble components, effectively removing impurities and improving the uniformity of the carbon source; simultaneously, it introduces MOF-based precursor materials and potassium hydroxide for synergistic effects, completing structural regulation and pore construction simultaneously during high-temperature carbonization, thus constructing a well-developed porous structure. In-situ doping is achieved using melamine as a nitrogen source, simplifying the traditional multi-step doping process, improving material preparation efficiency, and providing a feasible path for low-cost, high-value-added utilization of tar residue.
[0026] The tar residue-based porous carbon material prepared by this method has a high specific surface area, hierarchical pore structure, and uniformly distributed nitrogen doping sites. Among them, the metal active component derived from the MOF-based precursor can promote the formation of defect structures during carbonization, improve the conductivity and interfacial reactivity of the material, and help the rapid diffusion of electrolyte ions and charge storage.
[0027] The tar residue-based porous carbon electrode material prepared by this invention has a compressive strength of 0.5 A•g. -1 At current densities up to 540 F•g -1 Ultra-high specific capacitance. Attached Figure Description
[0028] Figure 1 The isothermal adsorption curve of the tar residue-based porous carbon electrode material prepared in Example 1 of this invention;
[0029] Figure 2 The isothermal adsorption curve of the tar residue-based porous carbon electrode material prepared in Example 3 of this invention;
[0030] Figure 3 This is a SEM image of the tar residue-based porous carbon electrode material prepared in Example 1 of the present invention;
[0031] Figure 4 This is a SEM image of the tar residue-based porous carbon electrode material prepared in Example 3 of the present invention;
[0032] Figure 5 Cyclic voltammetry curves of the tar residue-based porous carbon electrode material prepared in Example 1 of this invention at different scan rates in a three-electrode system using 6M potassium hydroxide as electrolyte;
[0033] Figure 6 Cyclic voltammetry curves of the tar residue-based porous carbon electrode material prepared in Example 3 of this invention at different scan rates in a three-electrode system using 6M potassium hydroxide as electrolyte;
[0034] Figure 7 The constant current charge-discharge curve of the tar residue-based porous carbon electrode material prepared in Example 1 of this invention;
[0035] Figure 8 The constant current charge-discharge curve of the tar residue-based porous carbon electrode material prepared in Example 3 of this invention;
[0036] Figure 9 The graph shows the 10,000-cycle charge-discharge and coulombic efficiency of the tar residue-based porous carbon electrode material prepared in Example 1 of this invention.
[0037] Figure 10 The diagram shows the 10,000-cycle charge-discharge and coulombic efficiency of the tar residue-based porous carbon electrode material prepared in Example 3 of this invention. Detailed Implementation
[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0039] Example 1
[0040] This invention discloses a method for preparing a porous carbon electrode material based on tar residue, the specific process of which is as follows:
[0041] ZIF-67 was used as the MOF-based precursor material. Preliminary experiments determined that, under the same calcination conditions, the carbonization yields of tar residue solubles (carbon source) and ZIF-67 were 5.3% and 62%, respectively. Based on these carbonization yields, the precursor feed mass was adjusted so that the final carbon material contained approximately 80% carbon derived from the carbon source and approximately 10% ZIF-67 derived components.
[0042] (1) Take a 5g tar residue sample and perform Soxhlet extraction on it with a mixed solvent of acetone and carbon disulfide in a volume ratio of 1:1 for 24h to obtain tar residue solubles, which can be used as carbon source.
[0043] (2) Weigh 1 g of carbon source, add 0.25 g of melamine and mix well; dissolve 1 g of KOH in anhydrous ethanol and slowly add it to the above system, stir and evaporate the solvent under water bath conditions to obtain the precursor; then add 0.010 g of ZIF-67 and mix well.
[0044] The resulting mixture was transferred to a ceramic boat and placed in a horizontal tube furnace at 700°C for 2 hours, with an N2 flow rate of 200 mL / min. -1 Allow it to cool to room temperature to obtain tar residue-based porous carbon.
[0045] (3) The tar residue-based porous carbon was magnetically stirred in a 1 M acid solution for 24 h, and then washed alternately with deionized water and ethanol until neutral; then dried in a drying oven at 80 °C for 24 h to obtain the tar residue-based porous carbon electrode material, denoted as N4Co. 10% PC 700 .
[0046] The process of preparing supercapacitor electrodes using this tar residue-based porous carbon electrode material:
[0047] Acetylene black, polyacrylamide, and the tar residue-based porous carbon electrode material prepared in Example 1 were uniformly mixed in a mass ratio of 1:1:8. Ethyl acetate was added to adjust the mixture into a slurry, which was then coated onto a current collector and dried. The slurry was then compacted under a pressure of 30 MPa to obtain a supercapacitor electrode.
[0048] The supercapacitor electrode was prepared in a three-electrode system using 6M KOH as the electrolyte at 0.5 A•g -1 The specific capacitance is relatively high at 508 F•g -1 .
[0049] Example 2
[0050] This invention discloses a method for preparing a porous carbon electrode material based on tar residue, the specific process of which is as follows:
[0051] ZIF-67 was used as the MOF-based precursor material. Preliminary experiments determined that, under the same calcination conditions, the carbonization yields of tar residue solubles (carbon source) and ZIF-67 were 5.3% and 62%, respectively. Based on these carbonization yields, the precursor feed mass was adjusted so that the final carbon material contained approximately 80% carbon derived from the carbon source and approximately 15% ZIF-67 derived components.
[0052] (1) Take a 5g tar residue sample and perform Soxhlet extraction on it with a mixed solvent of acetone and carbon disulfide in a volume ratio of 1:1 for 24h to obtain tar residue solubles, which can be used as carbon source.
[0053] (2) Weigh 1 g of carbon source, add 0.25 g of melamine and mix well; dissolve 1 g of KOH in anhydrous ethanol and slowly add it to the above system, stir and evaporate the solvent under water bath conditions to obtain the precursor; then add 0.016 g of ZIF-67 and mix well.
[0054] The resulting mixture was transferred to a ceramic boat and placed in a horizontal tube furnace at 700°C for 2 hours, with an N2 flow rate of 200 mL / min. -1 Allow it to cool to room temperature to obtain tar residue-based porous carbon.
[0055] (3) The tar-based porous carbon was magnetically stirred in a 1 M acid solution for 24 h, and then washed with deionized water and ethanol alternately until neutral; then dried in a drying oven at 80 °C for 24 h to obtain the tar-based porous carbon electrode material.
[0056] The process of preparing supercapacitor electrodes using this tar residue-based porous carbon electrode material:
[0057] Acetylene black, polyacrylamide, and tar residue-based porous carbon electrode material were uniformly mixed in a mass ratio of 1:1:8. Ethyl acetate was added to adjust the mixture into a slurry, which was then coated onto a current collector and dried. The slurry was then compacted under a pressure of 30 MPa to obtain a supercapacitor electrode.
[0058] The supercapacitor electrode was prepared in a three-electrode system using 6M KOH as the electrolyte at 0.5 A•g -1 At that time, the specific capacitance was relatively high at 435 F•g -1 .
[0059] Example 3
[0060] This invention discloses a method for preparing a porous carbon electrode material based on tar residue, the specific process of which is as follows:
[0061] Core-shell ZIF-67@mZrO2 composite material was used as the MOF-based precursor material. Preliminary experiments determined that, under the same calcination conditions, the carbonization yields of tar residue solubles (carbon source) and ZIF-67@mZrO2 composite material were 5.3% and 44%, respectively. Based on the carbonization yields, the precursor feed mass was adjusted so that the final carbon material contained approximately 80% carbon derived from the carbon source and approximately 10% ZIF-67@mZrO2 derived components.
[0062] (1) Take a 5g tar residue sample and perform Soxhlet extraction on it with a mixed solvent of acetone and carbon disulfide in a volume ratio of 1:1 for 24h to obtain tar residue solubles, which can be used as carbon source.
[0063] (2) Weigh 1 g of carbon source, add 0.25 g of melamine and mix well; dissolve 1 g of KOH in anhydrous ethanol and slowly add it to the above system, stir and evaporate the solvent under water bath conditions to obtain the precursor; then add 0.015 g of ZIF-67@mZrO2 and mix well.
[0064] The resulting mixture was transferred to a ceramic boat and placed in a horizontal tube furnace at 700°C for 2 hours, with an N2 flow rate of 200 mL / min. -1 Allow it to cool to room temperature to obtain tar residue-based porous carbon.
[0065] (3) The tar residue-based porous carbon was magnetically stirred in a 1 M acid solution for 24 h, and then washed alternately with deionized water and ethanol until neutral; then dried in a drying oven at 80 °C for 24 h to obtain the tar residue-based porous carbon electrode material, denoted as N4Zr(Co). 10% PC 700 .
[0066] The process of preparing supercapacitor electrodes using this tar residue-based porous carbon electrode material:
[0067] Acetylene black, polyacrylamide, and tar residue-based porous carbon electrode material were uniformly mixed in a mass ratio of 1:1:8. Ethyl acetate was added to adjust the mixture into a slurry, which was then coated onto a current collector and dried. The slurry was then compacted under a pressure of 30 MPa to obtain a supercapacitor electrode.
[0068] The supercapacitor electrode was prepared in a three-electrode system using 6M KOH as the electrolyte at 0.5 A•g -1 At that time, the specific capacitance was relatively high at 540 F•g. -1 .
[0069] Example 4
[0070] This invention discloses a method for preparing a porous carbon electrode material based on tar residue, the specific process of which is as follows:
[0071] Core-shell ZIF-67@mZrO2 composite material was used as the MOF-based precursor material. Preliminary experiments determined that, under the same calcination conditions, the carbonization yields of tar residue solubles (carbon source) and ZIF-67@mZrO2 composite material were 5.3% and 44%, respectively. Based on the carbonization yields, the precursor feed mass was adjusted so that the final carbon material contained approximately 80% carbon derived from the carbon source and approximately 15% ZIF-67@mZrO2 derived components.
[0072] (1) Take a 5g tar residue sample and perform Soxhlet extraction on it with a mixed solvent of acetone and carbon disulfide in a volume ratio of 1:1 for 24h to obtain tar residue solubles, which can be used as carbon source.
[0073] (2) Weigh 1 g of carbon source, add 0.25 g of melamine and mix well; dissolve 1 g of KOH in anhydrous ethanol and slowly add it to the above system, stir and evaporate the solvent under water bath conditions to obtain the precursor; then add 0.023 g of ZIF-67@mZrO2 and mix well.
[0074] The resulting mixture was transferred to a ceramic boat and placed in a horizontal tube furnace at 700°C for 2 hours, with an N2 flow rate of 200 mL / min. -1 Allow it to cool to room temperature to obtain tar residue-based porous carbon.
[0075] (3) The tar-based porous carbon was magnetically stirred in a 1 M acid solution for 24 h, and then washed with deionized water and ethanol alternately until neutral; then dried in a drying oven at 90 °C for 20 h to obtain the tar-based porous carbon electrode material.
[0076] The process of preparing supercapacitor electrodes using this tar residue-based porous carbon electrode material:
[0077] Acetylene black, polyacrylamide, and tar residue-based porous carbon electrode material were uniformly mixed in a mass ratio of 1:1:8. Ethyl acetate was added to adjust the mixture into a slurry, which was then coated onto a current collector and dried. The slurry was then compacted under a pressure of 30 MPa to obtain a supercapacitor electrode.
[0078] The supercapacitor electrode was prepared in a three-electrode system using 6M KOH as the electrolyte at 0.5 A•g -1 At that time, the specific capacitance was relatively high at 474 F•g -1 .
[0079] The following are tests conducted on the tar residue-based porous carbon electrode materials obtained in Examples 1 and 3.
[0080] Table 1 shows the surface physical characteristics of the tar residue-based porous carbon electrode materials prepared in Examples 1 and 3.
[0081]
[0082] a BET method; b t-plot method; c The adsorption amount was calculated using the t-plot method at P / P0 = 0.99.
[0083] As can be seen from the table, both tar residue-based porous carbon electrode materials possess high specific surface areas and abundant pore structures. Among them, N4Co... 10% PC 700 The total specific surface area reaches 1550.7 m². 2 •g -1 The average pore size is 1.90 nm; N4Zr(Co) 10% PC 700 The total specific surface area reaches 1923.3 m². 2 •g -1 The average pore size is 1.73 nm. The abundant microporous structure and large pore volume are conducive to the transport and storage of electrolyte ions, giving the obtained tar residue-based porous carbon electrode material excellent electrochemical performance.
[0084] Figures 1-2 The isothermal adsorption curves are shown for the tar residue-based porous carbon electrode materials prepared in Examples 1 and 3, respectively. Figure 1 As can be seen from this, N4Co 10% PC 700 It exhibits typical type I / IV adsorption curve characteristics, indicating that it possesses abundant microporous and mesoporous structures, which are beneficial for the rapid transport of electrolyte ions and charge storage; from Figure 2 As can be seen from this, N4Zr(Co) 10% PC 700 It exhibits typical type I adsorption curve characteristics, indicating that it has abundant microporous structure and high specific surface area, which is beneficial to improving the charge storage capacity of the material.
[0085] Figures 3-4 The images show SEM images of the tar residue-based porous carbon electrode materials prepared in Examples 1 and 3, respectively. Both materials have a well-developed honeycomb structure.
[0086] Figures 5-6 The figures show the cyclic voltammetry curves of the tar residue-based porous carbon electrode materials prepared in Examples 1 and 3 at different scan rates. As can be seen from the figures, the CV curves of both are slightly deformed rectangles, indicating that the overall capacitance is the result of the electric double-layer capacitance and pseudocapacitance.
[0087] Figures 7-8 The constant current charge-discharge curves of the tar residue-based porous carbon electrode materials prepared in Examples 1 and 3 are shown below under different current densities. 6M KOH was used as the electrolyte, and N₄Co was used as the electrolyte. 10% PC 700 At a current density of 0.5 A•g -1 The specific capacitance reaches 508 F•g -1 N4Zr(Co) 10% PC 700 At a current density of 0.5 A•g -1 The specific capacitance reaches 540 F•g -1 .
[0088] Figures 9-10 The graphs show the 10,000-cycle charge-discharge and coulombic efficiency of the tar residue-based porous carbon electrode materials prepared in Examples 1 and 3, respectively. (N4Co) 10% PC 700 After 10,000 cycles, the capacitance retention was 97% and the coulombic efficiency was 101%; N4Zr(Co) 10% PC 700 After 10,000 cycles, the capacitance retention was 94% and the coulombic efficiency was 100%.
[0089] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.
Claims
1. A method for preparing a porous carbon electrode material based on tar residue, characterized in that, Specifically, the following steps are included: S1. The tar residue sample was subjected to Soxhlet extraction using a mixed solvent of acetone and carbon disulfide to obtain tar residue solubles, which were used as a carbon source. S2. After mixing the carbon source obtained in step S1 with melamine in a certain proportion, KOH solution is added, and the mixture is stirred and the solvent is removed under water bath conditions to obtain a precursor. Then MOF-based precursor material is added and mixed evenly. The mixture is placed in a horizontal tube furnace and reacted under high temperature and N2 conditions. After cooling to room temperature, tar residue-based porous carbon is obtained. S3. The tar residue-based porous carbon obtained in step S2 is placed in an acid solution and magnetically stirred. It is then washed with deionized water and ethanol until neutral, and then dried to obtain the tar residue-based porous carbon electrode material.
2. The method for preparing a tar residue-based porous carbon electrode material as described in claim 1, characterized in that, In step S1, the volume ratio of acetone to carbon disulfide is 1:(0.8~1.2); the solid-liquid ratio of the tar residue sample to the mixed solvent is 1:(20~60) g•mL. -1 Soxhlet extraction time is 12-48 hours.
3. The method for preparing a tar residue-based porous carbon electrode material as described in claim 2, characterized in that, In step S2, the MOF-based precursor material is selected from ZIF-67 or core-shell ZIF-67@mZrO2 composite material, and the mass ratio of carbon source to MOF-based precursor material is 8: (0.5~1.5).
4. The method for preparing a tar residue-based porous carbon electrode material as described in claim 3, characterized in that, In step S2, the mass ratio of melamine, carbon source and KOH is (0.2~0.3):1:(0.8~1.2).
5. The method for preparing a tar residue-based porous carbon electrode material as described in claim 4, characterized in that, In step S2, the reaction conditions are controlled as follows: temperature 600~800℃, time 1~3h, and N2 flow rate 180~220 mL•min. -1 .
6. The method for preparing a tar residue-based porous carbon electrode material as described in claim 5, characterized in that, The acid solution in step S3 is a hydrochloric acid solution with a mass concentration of 0.8~1.2 mol·L⁻¹. -1 The drying temperature is 70~90℃, and the drying time is 20~28h.
7. A porous carbon electrode material based on tar residue prepared by the preparation method described in claim 6.
8. A supercapacitor electrode made using the tar residue-based porous carbon electrode material as described in claim 7.
9. The method for preparing a supercapacitor electrode as described in claim 8, characterized in that, A conductive agent, binder, and tar-based porous carbon electrode material in a mass ratio of 1:(0.5~1.5):(7~9) were uniformly mixed, and a solvent was added to form a slurry. This slurry was then coated onto nickel foam and dried, with an area of 0.8~1.2 cm². 2 The electrode of the supercapacitor is obtained by compacting it under a pressure of 10~40MPa.
10. The method for preparing a supercapacitor electrode as described in claim 9, characterized in that, The conductive agent is acetylene black; the binder includes one or more of polytetrafluoroethylene, polyacrylamide, polybutadiene, polyvinylpyrrolidone, polyethylene oxide, fluororubber, and polyvinyl alcohol; the solvent includes one or more of alcohols, water, ethyl acetate, dimethyl carbonate, methyl propionate, and diethyl carbonate.