NiS-based composite electrode material for supercapacitor and preparation method of NiS-based composite electrode material

Abstract

The invention discloses a NiS-based composite electrode material for a supercapacitor and a preparation method. The preparation method specifically comprises the following steps: step 1, preparing a TiO2 / NiO heterojunction material; step 2, preparing a TiO2 / NiS heterojunction material; step 3, preparing a DMF-aqueous solution, preparing a PTA solution through the DMF-aqueous solution, and adding the TiO2 / NiS heterojunction material into the PTA solution to obtain a TiO2 / NiS / MOF heterojunction material; and step 4, mixing the TiO2 / NiS / MOF heterojunction material, acetylene black, polyvinylidene fluoride and N-methyl pyrrolidone to prepare slurry, and coating a foamed nickel base material with the slurry to obtain the composite electrode material. According to the invention, the specific capacitance and the cycling stability of the electrode are improved by combining the high capacity characteristic of the TiO2 / NiS heterojunction with the high conductivity, the ion diffusion capability and the structure supporting effect of the MOF.

Description

Technical Field

[0001] The present invention belongs to the technical field of supercapacitor electrode materials, and in particular relates to a NiS-based composite electrode material for supercapacitors and a preparation method thereof. Background Art

[0002] In recent years, supercapacitors have attracted widespread attention as a promising energy storage device. Compared with traditional batteries, supercapacitors have the advantages of fast charging and discharging, high power density and long cycle life. However, these properties depend to a large extent on the selection and design of electrode materials, especially the conductivity and structural stability of the materials.

[0003] Transition metal sulfides have become a hot topic in the research of supercapacitor electrode materials due to their high theoretical specific capacitance, abundant redox reaction sites and low cost. Among them, nickel sulfide (NiS) and its various crystal structures (such as α-NiS, β-NiS, Ni3S2, etc.) are considered to be very promising electrode materials due to their mixed valence and excellent electrochemical properties. However, pure nickel sulfide still faces many challenges in practical applications, such as poor cycle stability, low conductivity, slow ion transport rate and performance degradation due to sulfur dissolution. At the same time, TiO2 has attracted widespread attention as an electrode material due to its wide potential window and excellent chemical stability. However, the semiconductor properties of TiO2 have poor conductivity and low theoretical specific capacitance (335mAh / g), which limits its application in supercapacitors.

[0004] Therefore, the development of new high-performance electrode materials based on TiO2 and NiS is of great significance to improving the overall performance of supercapacitors. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a NiS-based composite electrode material for a supercapacitor, which improves the specific capacitance and cycle stability of the electrode by combining the high capacity characteristics of the TiO2 / NiS heterojunction with the high conductivity and ion diffusion capacity and structural support of MOF.

[0006] Another object of the present invention is to provide a NiS-based composite electrode material for supercapacitors.

[0007] The first technical solution adopted by the present invention is a method for preparing a NiS-based composite electrode material for a supercapacitor, which specifically comprises the following steps: Step 1, preparing TiO2 / NiO heterojunction material; Step 2, mixing the TiO2 / NiO heterojunction material prepared in step 1 with a Na2S solution to prepare a TiO2 / NiS heterojunction material; Step 3, preparing a DMF-water solution, adding terephthalic acid to the DMF-water solution to obtain a PTA solution, adding a TiO2 / NiS heterojunction material to the PTA solution, and reacting the solution to obtain a TiO2 / NiS / MOF heterojunction material; Step 4: Mix the TiO2 / NiS / MOF heterojunction material, acetylene black and polyvinylidene fluoride, and add N-methylpyrrolidone thereto to prepare a slurry, apply the mixed slurry on a nickel foam substrate, and obtain a composite material electrode after drying and pressurizing.

[0008] The first technical solution of the present invention is also characterized in that: The preparation of TiO2 / NiO heterojunction material in step 1 specifically includes the following steps: Step 1.1, preparing TiO2 dispersion and starch solution; Step 1.2, drop the TiO2 dispersion into the starch solution and continue stirring for 30 min to 60 min; Step 1.3, add 0.01 mol of Ni(NO3)2 to the stirred starch solution, and continue stirring for 20 min to 30 min to obtain a mixed solution; Step 1.4, stirring the mixed solution at a constant temperature of 80°C to 85°C for 5min to 10min, adding 3ml of concentrated ammonia water with a concentration of 25% to 28% to the mixed solution, and continuing to stir for 30min to 40min, and then allowing the mixed solution to precipitate to obtain a precipitate; Step 1.5, using deionized water to perform ultrasonic centrifugal cleaning on the precipitate for 3 to 5 times, drying the cleaned precipitate at 80°C to 100°C for 10h to 12h, and annealing the dried precipitate in air at 450°C to 500°C for 2h to 3h to obtain a TiO2 / NiO heterojunction material.

[0009] In step 1.1, the TiO2 dispersion is prepared by weighing 0.001 g to 0.01 g of P25 powder, adding it to 5 ml of deionized water, and performing ultrasonic dispersion to obtain the TiO2 dispersion; The starch solution is prepared by adding 3g~7g of soluble starch to 150ml of deionized water, and heating to 100°C while stirring until it becomes a transparent gel.

[0010] The pH of the mixed solution after adding concentrated ammonia water in step 1.4 is 8-9; In step 1.5, the pH value of the solution is neutral after the precipitate is ultrasonically centrifuged and cleaned 3 to 5 times with deionized water.

[0011] The concentration of the Na2S solution in step 2 is 0.05mol / L~0.1mol / L; The molar ratio of TiO2 / NiO heterojunction material and Na2S solution is 1g:300ml.

[0012] The mixing and preparation of the TiO2 / NiS heterojunction material in step 2 is specifically to seal the mixed solution of the TiO2 / NiO heterojunction material and the Na2S solution at a temperature of 200°C~240°C and heat it for 9h~12h, then wait for the solution to cool and precipitate naturally, and then use ionized water and anhydrous ethanol to centrifuge and wash the precipitate for 3~5 times to obtain the TiO2 / NiS heterojunction material.

[0013] The DMF-water solution in step 3 is prepared by mixing dimethylformamide and deionized water in a volume ratio of 2:1 to obtain the DMF-water solution; The ratio of terephthalic acid to DMF-water solution is 1 g:600 ml; The reaction treatment after adding the TiO2 / NiS heterojunction material to the PTA solution is specifically as follows: adding the TiO2 / NiS heterojunction material to the PTA solution and stirring for 10 min to 20 min, and then sealing the mixed solution and heating it at a temperature of 150° C. for 9 h to 12 h; Then, after the solution is naturally cooled to room temperature, the precipitate is centrifugally washed 3 to 5 times with ionized water and anhydrous ethanol, and dried in air at 60°C to 80°C for 10h to 12h to obtain a TiO2 / NiS / MOF heterojunction material.

[0014] In step 3, the amount ratio of TiO2 / NiS heterojunction material to PTA solution is 1g:150ml.

[0015] The mass ratio of TiO2 / NiS / MOF heterojunction material, acetylene black and polyvinylidene fluoride is 8:1:1; Add N-methylpyrrolidone while grinding, the ratio of TiO2 / NiS / MOF heterojunction material and N-methylpyrrolidone is 1 mg: 60 μl; The drying process was carried out at a temperature of 60° C. for 12 h, and the pressure of the pressurization process was 10 MPa.

[0016] The second technical solution adopted by the present invention is that the NiS-based composite electrode material for supercapacitor is prepared by the above-mentioned method for preparing the NiS-based composite electrode material for supercapacitor.

[0017] The beneficial effects of the present invention are: (1) The preparation method of the NiS-based composite electrode material for supercapacitors of the present invention forms a three-dimensional colloidal network by gelatinizing soluble starch, which is used as a soft template to uniformly disperse TiO2 and guide the confined hydrolysis of Ni²⁺ to Ni(OH)2, thereby effectively inhibiting particle agglomeration and achieving efficient synthesis and performance optimization of TiO2 / NiO heterojunctions; the synergistic effect of TiO2 double-layer energy storage and NiS pseudocapacitance contribution is then utilized to improve the specific capacity, and the internal electric field design of the TiO2 / NiS heterojunction interface is used to improve the carrier transmission and enhance the electrode surface reaction activity, thereby achieving high-rate charge and discharge; a porous structure of the TiO2 / NiS heterojunction supported by 3DMOF is constructed to accelerate ion transmission and buffer cyclic stress, thereby significantly extending the device life.

[0018] (2) The preparation method of the NiS-based composite electrode material for supercapacitors of the present invention provides Ni²⁺ / Ti³⁺ metal atomic centers in situ on the TiO2 / NiS surface, which are self-assembled in situ with terephthalic acid to form a firmly bonded MOF framework, thereby optimizing the electrode interface stability, ion transport kinetics and active site density, and realizing the construction of high-performance energy storage materials without the introduction of exogenous metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic flow diagram of a method for preparing a NiS-based composite electrode material for a supercapacitor of the present invention; Figure 2 is an X-ray diffraction pattern of the TiO2 / NiS / MOF composite electrode of the present invention; Figure 3 This is a low-magnification scanning electron microscope image of the TiO2 / NiS / MOF composite electrode of the present invention; Figure 4 This is a high-magnification scanning electron microscope image of the TiO2 / NiS / MOF composite electrode of the present invention; Figure 5 It is a graph of the cycle stability and coulombic efficiency of the TiO2 / NiS / MOF electrode of the present invention at 3A / g in a three-electrode system.

[0020] Figure 6 It is a graph of cycle stability and coulombic efficiency of the TiO2 / NiS / MOF / / AC supercapacitor of the present invention at 3A / g in a double electrode system; DETAILED DESCRIPTION The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] The preparation method of the NiS-based composite electrode material for supercapacitors of the present invention combines MOFs with TiO2 / NiS heterojunctions through interface engineering and three-dimensional mesh nanostructure design to improve the overall performance of supercapacitors. The high capacity characteristics of the TiO2 / NiS heterojunction are combined with the high conductivity, ion diffusion capacity and structural support of MOF to significantly improve the specific capacitance and cycle stability of the electrode. The specific examples are shown in the following.

[0022] Example 1 The invention discloses a method for preparing a NiS-based composite electrode material for supercapacitors, such as Figure 1 As shown, the specific steps include: Step 1, preparing TiO2 / NiO heterojunction material; Step 2, mixing the TiO2 / NiO heterojunction material prepared in step 1 with a Na2S solution to prepare a TiO2 / NiS heterojunction material; Step 3, preparing a dimethylformamide (DMF)-water solution, adding terephthalic acid (PTA) to the DMF-water solution to obtain a PTA solution, adding a TiO2 / NiS heterojunction material to the PTA solution, and then reacting to obtain a TiO2 / NiS / MOF heterojunction material; Step 4: Mix the TiO2 / NiS / MOF heterojunction material, acetylene black and polyvinylidene fluoride, add N-methylpyrrolidone thereto to prepare a slurry, apply the mixed slurry on a nickel foam (NF) substrate, and obtain a composite material electrode after drying and pressurizing.

[0023] The composite electrode material prepared in this embodiment is subjected to X-ray diffraction to obtain an XRD spectrum, such as Figure 2 As shown, the XRD spectrum shows the typical diffraction peaks of the rhombic NiS structure, and the peaks at 31.1° and 55.15° are attributed to the (110) and (122) crystal planes of Ni3S2 (JCPDS 97-003-6338). Due to the low content and dense coating structure, the characteristic peaks of TiO2 were not detected; the test also did not find the characteristic peaks of MOF. This result confirms that the composite material has good crystallinity and small particle size, and the XRD characteristics effectively confirm the phase composition of the TiO2 / NiS / MOF composite electrode.

[0024] Example 2 In this embodiment, based on the embodiment 1, the preparation method of the NiS-based composite electrode material for supercapacitors of the present invention in step 1 specifically comprises the following steps: Step 1.1, weigh 0.001g~0.01g of P25 (TiO2) powder and add it to 5ml of deionized water for ultrasonic dispersion to obtain a TiO2 dispersion; then add 3g~7g of soluble starch to 150ml of deionized water, and heat to 100℃ while stirring until it becomes a transparent gel; Step 1.2, drop the TiO2 dispersion into the starch solution and continue stirring for 30 min to 60 min; Step 1.3, add 0.01 mol of Ni(NO3)2 to the stirred starch solution, continue stirring for 20 min to 30 min, and obtain a mixed solution after it is completely dissolved; Step 1.4, stirring the mixed solution at a constant temperature of 80°C to 85°C for 5min to 10min, adding 3ml of concentrated ammonia water with a concentration of 25% to 28% to the mixed solution, adjusting the pH value of the mixed solution to 8 to 9, and continuing to stir for 30min to 40min to allow the mixed solution to precipitate and obtain a precipitate; Step 1.5, use deionized water to perform ultrasonic centrifugal cleaning on the precipitate for 3 to 5 times, the pH value of the solution after cleaning is neutral, the cleaned precipitate is dried at 80°C to 100°C for 10h to 12h, and the dried precipitate is annealed in air at 450°C to 500°C for 2h to 3h to obtain a TiO2 / NiO heterojunction material.

[0025] The composite electrode material prepared in this embodiment is subjected to low-magnification electron microscope scanning and high-magnification electron microscope scanning respectively; like Figure 3 As shown, a low-magnification SEM image of the TiO2 / NiS / MOF electrode shows a fluffy bulk structure in which a network of MOFs is inserted between the TiO2 / NiS particles, effectively connecting them together. This network structure enhances the conductivity and stability of the TiO2 / NiS material.

[0026] like Figure 4 As shown in Figure 2, the introduction of MOF significantly increased the porosity between TiO2 / NiS particles and significantly reduced their size. The reduction in the size of TiO2 / NiS particles effectively increased the specific surface area of ​​the electrode, provided more active sites for the reaction, and improved the specific capacitance of the electrode. In addition, the fluffy porous structure supported by MOF promoted electrolyte penetration and increased OH in the electrode process. - The diffusion rate of ions is increased, thereby accelerating the electrochemical reaction rate on the electrode surface. These results indicate that the introduction of MOF plays a crucial role in adjusting the arrangement of TiO2 / NiS particles.

[0027] Example 3 In this embodiment, based on Example 2, in step 2 of the method for preparing a NiS-based composite electrode material for a supercapacitor of the present invention, the concentration of the Na2S solution is 0.05 mol / L~0.1 mol / L; the amount ratio of the TiO2 / NiO heterojunction material to the Na2S solution is 1 g:300 ml.

[0028] Furthermore, the mixing and preparation of the TiO2 / NiS heterojunction material in step 2 is specifically performed by sealing the mixed solution of the TiO2 / NiO heterojunction material and the Na2S solution at a temperature of 200°C~240°C and heating it for 9h~12h, and then after the reaction is complete and the solution is naturally cooled and precipitated, the precipitate is centrifugally washed 3~5 times with ionized water and anhydrous ethanol to obtain the NiS / TiO2 heterojunction material.

[0029] Example 4 In this embodiment, based on the embodiment 3, the DMF-water solution is prepared in step 3 of the method for preparing the NiS-based composite electrode material for supercapacitors of the present invention, specifically by mixing dimethylformamide and deionized water in a volume ratio of 2:1 to obtain the DMF-water solution; Terephthalic acid was added to the DMF-water solution to obtain a PTA solution, and the ratio of terephthalic acid to the DMF-water solution was 1 g: 600 ml.

[0030] Furthermore, the reaction treatment after adding TiO2 / NiS heterojunction material to the PTA solution is specifically as follows: according to the ratio of TiO2 / NiS heterojunction material to PTA solution of 1g:150ml, the TiO2 / NiS heterojunction material is added to the PTA solution and stirred for 10min~20min, and then the mixed solution is sealed and stirred and heated at a temperature of 150°C for 9h~12h.

[0031] After the reaction is completed and the solution is naturally cooled to room temperature, the precipitate is centrifugally washed 3 to 5 times with ionized water and anhydrous ethanol, and dried in air at 60°C to 80°C for 10h to 12h to obtain a TiO2 / NiS / MOF heterojunction material.

[0032] Example 5 The preparation method of the NiS-based composite electrode material for supercapacitors of the present invention comprises the following steps: ultrasonically dispersing P25 (TiO2) powder in deionized water to obtain a TiO2 dispersion; separately dissolving soluble starch in deionized water, continuously stirring and heating until boiling to present a transparent colloid state. Subsequently, the TiO2 dispersion is dropwise added to the starch solution, and Ni (NO3) 2 is added after stirring and continuously stirred until completely dissolved, and then transferred to a constant temperature environment, continuously stirred, and concentrated ammonia water is added dropwise to adjust the pH to 8-9. After heating and stirring, the precipitate is collected, and repeatedly ultrasonically centrifuged with deionized water until the solution is neutral, and finally the precipitate is dried and annealed in an air atmosphere to obtain a TiO2 / NiO heterojunction material.

[0033] Then, a Na2S solution is prepared, and the obtained TiO2 / NiO heterojunction material is immersed in the solution, and then sealed and heated. After the reaction, the precipitate is naturally cooled and washed by centrifugation with deionized water and anhydrous ethanol to obtain a TiO2 / NiS heterojunction material.

[0034] Then, a dimethylformamide DMF-water solution (Solution A) was prepared, and terephthalic acid (PTA) was dissolved to obtain Solution B. The TiO2 / NiS heterojunction material was added to Solution B and stirred and dispersed, and then sealed and heated and stirred. After the reaction was completed and cooled naturally, it was centrifugally washed with deionized water and anhydrous ethanol, and dried to obtain the TiO2 / NiS / MOF heterojunction material.

[0035] Finally, TiO2 / NiS / MOF heterojunction material, acetylene black and polyvinylidene fluoride were mixed in a mass ratio of 8:1:1, and an appropriate amount of N-methylpyrrolidone (NMP) was gradually added and ground to prepare a slurry. The ratio of TiO2 / NiS / MOF heterojunction material and N-methylpyrrolidone was 1 mg:60 μl.

[0036] The slurry was then uniformly coated on a nickel foam (NF) substrate, dried at 60 °C for 12 h, and pressed at a pressure of 10 MPa, with the final mass loading of the TiO2 / NiS / MOF composite on the electrode being approximately 10 mg.

[0037] The prepared positive electrode, activated carbon (AC) negative electrode and PVA-KOH gel electrolyte were used to assemble the gel state hybrid supercapacitor and perform performance tests at 3A / g in a three-electrode system and 3A / g in a two-electrode system.

[0038] like Figure 5 As shown, after 5000 cycles, the TiO2 / NiS / MOF / / AC device retains 83% of its initial capacitance, demonstrating excellent cycling stability, while the Coulombic efficiency remains almost constant, close to 100%.

[0039] like Figure 6As shown, after 5000 cycles, the TiO2 / NiS / MOF / / AC supercapacitor retains 83% of its initial capacitance, demonstrating excellent cycling stability, while the Coulombic efficiency remains almost constant, close to 100%.

[0040] Example 6 The NiS-based composite electrode material for a supercapacitor of the present invention is prepared by adopting the above-mentioned method for preparing the NiS-based composite electrode material for a supercapacitor.

[0041] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0042] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a NiS-based composite electrode material for a supercapacitor, characterized in that: The specific steps include: Step 1, preparing TiO2 / NiO heterojunction material; Step 2, mixing the TiO2 / NiO heterojunction material prepared in step 1 with a Na2S solution to prepare a TiO2 / NiS heterojunction material; Step 3, preparing a DMF-water solution, adding terephthalic acid to the DMF-water solution to obtain a PTA solution, adding a TiO2 / NiS heterojunction material to the PTA solution, and reacting the solution to obtain a TiO2 / NiS / MOF heterojunction material; Step 4: Mix the TiO2 / NiS / MOF heterojunction material, acetylene black and polyvinylidene fluoride, and add N-methylpyrrolidone thereto to prepare a slurry, apply the mixed slurry on a nickel foam substrate, and obtain a composite material electrode after drying and pressurizing.

2. The method for preparing a NiS-based composite electrode material for a supercapacitor according to claim 1, characterized in that: The preparation of the TiO2 / NiO heterojunction material in step 1 specifically comprises the following steps: Step 1.1, preparing TiO2 dispersion and starch solution; Step 1.2, drop the TiO2 dispersion into the starch solution and continue stirring for 30 min to 60 min; Step 1.3, add 0.01 mol of Ni(NO3)2 to the stirred starch solution, and continue stirring for 20 min to 30 min to obtain a mixed solution; Step 1.4, stirring the mixed solution at a constant temperature of 80°C to 85°C for 5min to 10min, adding 3ml of concentrated ammonia water with a concentration of 25% to 28% to the mixed solution, and continuing to stir for 30min to 40min, and then allowing the mixed solution to precipitate to obtain a precipitate; Step 1.5, using deionized water to perform ultrasonic centrifugal cleaning on the precipitate for 3 to 5 times, drying the cleaned precipitate at 80°C to 100°C for 10h to 12h, and annealing the dried precipitate in air at 450°C to 500°C for 2h to 3h to obtain a TiO2 / NiO heterojunction material.

3. The method for preparing a NiS-based composite electrode material for a supercapacitor according to claim 2, characterized in that: The TiO2 dispersion in step 1.1 is prepared by weighing 0.001 g to 0.01 g of P25 powder and adding it to 5 ml of deionized water for ultrasonic dispersion to obtain the TiO2 dispersion; The starch solution is prepared by adding 3g~7g of soluble starch to 150ml of deionized water, and heating to 100°C while stirring until it becomes a transparent gel.

4. The method for preparing a NiS-based composite electrode material for a supercapacitor according to claim 2, characterized in that: The pH of the mixed solution after adding concentrated ammonia in step 1.4 is 8-9; In step 1.5, the pH value of the solution is neutral after the precipitate is ultrasonically centrifuged and cleaned 3 to 5 times with deionized water.

5. The method for preparing a NiS-based composite electrode material for a supercapacitor according to claim 1, characterized in that: The concentration of the Na2S solution in step 2 is 0.05 mol / L to 0.1 mol / L; The amount ratio of the TiO2 / NiO heterojunction material to the Na2S solution is 1g:300ml.

6. The method for preparing a NiS-based composite electrode material for a supercapacitor according to claim 1, characterized in that: The mixing and preparation of the TiO2 / NiS heterojunction material in step 2 is specifically to seal the mixed solution of the TiO2 / NiO heterojunction material and the Na2S solution at a temperature of 200°C~240°C and heat it for 9h~12h, and then after the solution is naturally cooled and precipitated, the precipitate is centrifugally washed 3~5 times with ionized water and anhydrous ethanol to obtain the TiO2 / NiS heterojunction material.

7. The method for preparing a NiS-based composite electrode material for a supercapacitor according to claim 1, characterized in that: The DMF-water solution in step 3 is specifically prepared by mixing dimethylformamide and deionized water in a volume ratio of 2:1 to obtain the DMF-water solution; The ratio of terephthalic acid to DMF-water solution is 1g:600ml; The reaction treatment after adding the TiO2 / NiS heterojunction material to the PTA solution is specifically as follows: adding the TiO2 / NiS heterojunction material to the PTA solution and stirring for 10 min to 20 min, and then sealing the mixed solution and heating it at a temperature of 150° C. for 9 h to 12 h; Then, after the solution is naturally cooled to room temperature, the precipitate is centrifugally washed 3 to 5 times with ionized water and anhydrous ethanol, and dried in air at 60°C to 80°C for 10h to 12h to obtain a TiO2 / NiS / MOF heterojunction material.

8. The method for preparing a NiS-based composite electrode material for a supercapacitor according to claim 1, characterized in that: In step 3, the amount ratio of the TiO2 / NiS heterojunction material to the PTA solution is 1g:150ml.

9. The method for preparing a NiS-based composite electrode material for a supercapacitor according to claim 1, characterized in that: The mass ratio of the TiO2 / NiS / MOF heterojunction material, acetylene black and polyvinylidene fluoride is 8:1:1; Grinding is performed while adding the N-methylpyrrolidone, wherein the ratio of the TiO2 / NiS / MOF heterojunction material to the N-methylpyrrolidone is 1 mg: 60 μl; The drying process is performed at a temperature of 60° C. for 12 hours, and the pressure of the pressurization process is 10 MPa.

10. NiS-based composite electrode material for supercapacitor, characterized in that: The material is prepared by the method for preparing a NiS-based composite electrode material for a supercapacitor as described in any one of claims 1 to 9.

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