Preparation method and application of two-dimensional molybdenum-tungsten ternary nitride material

Abstract

The invention discloses a preparation method and application of a two-dimensional molybdenum-tungsten ternary nitride material, which comprises the following steps of: grinding and mixing low-cost molybdenum disulfide and tungsten disulfide serving as precursors with alkali metal salt by adopting a molten salt method, and performing heat treatment in an ammonia-containing atmosphere to prepare a two-dimensional molybdenum-tungsten ternary nitride in one step; the preparation process is carried out in a molten salt environment, and molybdenum and tungsten bimetal can be effectively promoted to form an interstitial solid solution; in the two-dimensional molybdenum-tungsten ternary nitride, molybdenum-tungsten bimetals can improve the electron transfer rate through a synergistic effect, so that the conductivity of the material can be remarkably improved, the two-dimensional structure can provide more active adsorption sites, the capacitive performance of the material in an electrolyte is effectively improved, and the material is a relatively promising supercapacitor electrode material. In addition, the related synthesis process is simple, the cost is low, the production efficiency is high, and large-scale industrial production is facilitated.

Description

Technical Field

[0001] This invention belongs to the field of electrochemistry and energy storage materials, specifically relating to the preparation method and application of two-dimensional molybdenum-tungsten ternary nitride materials. Background Technology

[0002] Supercapacitors are a novel type of electrochemical energy storage device that falls between traditional capacitors and batteries. They possess advantages such as fast charging and discharging speeds, long cycle life, and high safety, and have attracted widespread attention in the energy storage field. However, current supercapacitors generally suffer from low energy density, particularly low volumetric energy density, which limits their widespread application. Electrode materials are a core component of supercapacitors, determining their energy storage performance. Developing novel electrode materials that combine high energy density and high power density is of great significance. Transition metal nitrides possess high pseudocapacitance, high conductivity, and good chemical stability, making them a promising class of supercapacitor electrode materials.

[0003] Molybdenum nitride (MoN), a typical interstitial metal compound, possesses metalloid conductivity and good capacitance properties, making it a potential high-power-density capacitor material. However, improving the capacity and cycle stability of MoN in acidic electrolytes remains a major challenge for its application. Preparing two-dimensional molybdenum-tungsten bimetallic nitrides can increase the active sites and improve electrochemical performance. Furthermore, the synergistic effect among the multi-metallic components can further enhance its physicochemical properties, resulting in superior capacitor electrode materials.

[0004] The literature “Adalati R, Kumar A, Kumar Y, A high performing asymmetric supercapacitor of Mo2N and VN infilms as binder free electrodegrown through reactive sputtering[J], Energy technology, 2020, 8: 2000-466” describes the preparation of molybdenum nitride films using sputtering technology. The molybdenum nitride prepared by this method does not require the addition of additional conductive agents and binders, making it a good electrode material for supercapacitors, but its capacity is relatively low. The literature “Kartachova O, Glušhenkov AM, Chen Y, et al. Bimetalic molybdenum tungsten oxynitride: structure and electrochemical properties[J]. Journal of Materials Chemistry A, 2013, 1(27): 7889-7895” reports a mesoporous molybdenum tungsten ternary nitride exhibiting capacitive properties in acidic electrolytes, but the preparation process is complex, the capacity is low, and the stability is poor. Patent CN114975921A discloses a preparation method and application of a one-dimensional flexible tungsten-niobium ternary nitride material. Using niobium oxalate, ammonium metatungstate, N,N-dimethylformamide, and polyacrylonitrile as main raw materials, a one-dimensional morphology is obtained by jet blasting technology, followed by heating and nitriding to obtain a one-dimensional tungsten-niobium ternary nitride. This preparation method has expensive raw material costs and a complicated process. The preparation methods reported above still suffer from complex processes and poor performance, making them unsuitable for large-scale industrial production. No method for preparing two-dimensional molybdenum-tungsten ternary nitrides in one step has been reported. Therefore, developing a simple, efficient, and high-performance method for preparing two-dimensional molybdenum-tungsten ternary nitrides is of great significance. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing a method for preparing two-dimensional molybdenum-tungsten ternary nitride materials and applying them to supercapacitors. By promoting the formation of interstitial solid solutions of the molybdenum-tungsten bimetallic compound through nitriding in a molten salt environment, the method directly achieves efficient conversion from bulk molybdenum and tungsten sulfide powders to a two-dimensional molybdenum-tungsten ternary transition metal compound. Furthermore, the preparation method is simple, convenient, and suitable for industrial application.

[0006] To achieve the above objectives, the technical solution adopted in this invention is a two-dimensional molybdenum-tungsten ternary nitride material, which is synthesized in one step by molten salt method using tungsten disulfide, molybdenum disulfide and sodium carbonate as the main raw materials.

[0007] The preparation method of the two-dimensional molybdenum-tungsten ternary nitride material of the present invention includes the following steps:

[0008] A method for preparing a two-dimensional molybdenum-tungsten ternary nitride material, characterized by comprising the following steps:

[0009] Step (1): Tungsten disulfide, molybdenum disulfide and sodium carbonate powder are directly and thoroughly ground to obtain a mixed powder with uniform particle size;

[0010] Step (2): The obtained mixed powder is heated in an argon atmosphere to above the powder melting point temperature under an argon atmosphere to fully melt the raw materials. Then, ammonia gas is introduced to maintain the temperature at the specified temperature. Finally, the mixture is cooled to room temperature to obtain the black product.

[0011] Step (3): The obtained black product is subjected to acid washing and water washing treatment;

[0012] Step (4): Place the washed product in a freeze dryer for drying.

[0013] The present invention also discloses a two-dimensional molybdenum-tungsten ternary nitride material, which is prepared by the above-mentioned two-dimensional molybdenum-tungsten ternary nitride material preparation method, characterized in that: the two-dimensional molybdenum-tungsten ternary nitride material is a two-dimensional nanosheet structure with molybdenum-tungsten bimetallic components.

[0014] The present invention also discloses a supercapacitor electrode material, which is prepared by the above-mentioned two-dimensional molybdenum-tungsten ternary nitride material preparation method.

[0015] The present invention also discloses a supercapacitor electrode material, characterized in that the material is the above-mentioned two-dimensional molybdenum-tungsten ternary nitride material.

[0016] Beneficial effects

[0017] In the two-dimensional molybdenum-tungsten ternary nitride material of the present invention, the activation energy is reduced by reacting in a molten salt environment, which promotes the formation of interstitial solid solutions of molybdenum-tungsten bimetallic compounds. The synergistic effect of the molybdenum-tungsten bimetallic components and the bonding effect between the interfaces of different components can enhance the electron transfer rate. At the same time, the two-dimensional structure of the molybdenum-tungsten ternary nitride material can provide more active sites and adsorption surfaces. The defect engineering introduced by it further accelerates the electron transfer, which is beneficial for the adsorption and transport of conductive particles in the electrolyte and increases the specific capacitance. The synergistic effect of the molybdenum-tungsten ternary nitride promotes the electrochemical redox reaction kinetics, further improving the cycle performance and rate performance. Attached Figure Description

[0018] Figure 1 This is a scanning electron microscope image of the tungsten-niobium ternary nitride material prepared in Example 1 of the present invention, magnified 8000x.

[0019] Figure 2 The image shown is a scanning electron microscope energy spectrum of the tungsten-niobium ternary nitride material prepared in Example 1 of this invention, magnified 8000x.

[0020] Figure 3 The XRD pattern of the tungsten-niobium ternary nitride material prepared in Example 1 of this invention;

[0021] Figure 4 This is a scanning electron microscope image (SEM) of the tungsten-niobium ternary nitride material prepared in Example 2 of the present invention, magnified 8000x.

[0022] Figure 5 This is a scanning electron microscope image (SEM) of the tungsten-niobium ternary nitride material prepared in Example 3 of the present invention, magnified 8000x.

[0023] Figure 6 The images shown are scanning electron microscope (SEM) images of the tungsten-niobium ternary nitride material of the present invention, magnified 8000x. (a) is a scanning electron microscope image of the tungsten-niobium ternary nitride material prepared in Comparative Example 1, magnified 8000x; (b) is a scanning electron microscope image of the tungsten-niobium ternary nitride material prepared in Comparative Example 2, magnified 8000x.

[0024] Figure 7 The XRD pattern of the tungsten-niobium ternary nitride material prepared in Comparative Example 3 is shown below.

[0025] Figure 8 The CV curve of the tungsten-niobium ternary nitride material prepared in Example 1 of this invention.

[0026] Figure 9 The tungsten-niobium ternary nitride material prepared in Example 1 of this invention, along with MoN and W, was prepared. 6.4 Comparison of N4's charge and discharge curves.

[0027] Figure 10 This is a cycle stability diagram of the tungsten-niobium ternary nitride material prepared in Example 1 of the present invention. Detailed Implementation

[0028] Example 1

[0029] The preparation method of the two-dimensional molybdenum-tungsten ternary nitride material in this embodiment includes the following steps:

[0030] (1) Weigh molybdenum disulfide, tungsten disulfide and sodium carbonate in a molar mass ratio of 1:1:6 into a mortar, add an appropriate amount of anhydrous ethanol and grind evenly to obtain a mixed powder, then transfer it to a porcelain boat; the molybdenum-tungsten raw material ratio must be kept uniform in order to obtain molybdenum-tungsten ternary nitride.

[0031] (2) Place the ceramic boat from step (1) into a tube furnace, heat it to 650°C at a heating rate of 5°C / min under an argon atmosphere and hold it for 1 hour, then heat it to 750°C at the same heating rate and switch to ammonia gas and hold it for 3 hours. The argon gas flow rate is 20 sccm and the ammonia gas flow rate is 100 sccm. Cool it to room temperature. The reason for first introducing argon gas and then ammonia gas is to prevent the raw material from reacting with ammonia gas before melting. First, introduce argon gas to heat it to 650°C to reach the melting point of the raw material so that it can be fully melted. Then, introduce ammonia gas to heat it to 750°C to reach the nitriding temperature of the raw material and react with ammonia gas.

[0032] (3) Take out the product obtained in step (2) and put it into a centrifuge tube. Add 40 ml of hydrochloric acid with a concentration of 0.1 mol / L, put it in a centrifuge and centrifuge at a speed of 6000 r / min. Then add deionized water in the same way and centrifuge and clean it. After cleaning and drying, the two-dimensional molybdenum tungsten ternary nitride material is obtained.

[0033] The two-dimensional molybdenum-tungsten ternary nitride material obtained in this embodiment was analyzed and tested. Figure 1 The image shown is a scanning electron microscope image of the product obtained in Example 1 of this invention. It can be seen that uniform two-dimensional nanosheets were obtained. The nanosheets are relatively thin and their size is approximately 1-3 μm.

[0034] Figure 2 The EDS spectrum of the product obtained in Example 1 of this invention shows that Mo, W and N elements are uniformly distributed on its surface, indicating that the obtained product is a molybdenum-tungsten ternary nitride.

[0035] The product obtained in Example 1 of this invention was subjected to X-ray diffraction analysis, and the results are shown in the figure. Figure 3 As shown, the characteristic peak of MoWN exhibits a larger full width at half maximum (FWHM) and a shift. This is because the introduction of W ions with smaller ionic radii relative to Mo ions in MoN leads to lattice contraction. Consequently, compared to MoN, the unique peak of MoWN in the XRD spectrum shifts to the right, and the FWHM increases. The peak position shift can be clearly observed in the inset at the top right.

[0036] The two-dimensional molybdenum-tungsten ternary nitride material obtained in this embodiment has the following structural characteristics: W partially replaces Mo to form a two-dimensional nanosheet structure of bimetallic solid solution, with uniform size of about 1-3 μm.

[0037] Application Example 1

[0038] The two-dimensional molybdenum-tungsten ternary nitride obtained in Example 1 of this invention was used to print electrodes for micro supercapacitors. The specific assembly steps are as follows: hydroxypropyl methylcellulose binder and a small amount of defoamer were added to deionized water, heated and stirred, and then the two-dimensional molybdenum-tungsten ternary nitride material was added to the stirred binder. After mixing, centrifugation was performed to remove bubbles and obtain ink with a certain viscosity. Using a screen printing template with a customized interdigitated pattern, PET was used as the substrate. The ink was evenly coated on the screen, and then a screen brush was used to press and print it. To make the printing uniform, the printing was repeated three times. H2SO4 / PVA gel electrolyte was drop-coated on the surface of the interdigitated pattern. Leads were connected from both sides using conductive copper foil, and then the encapsulation was completed using tape.

[0039] The obtained micro supercapacitor was characterized by electrochemical testing, and the results are shown in the figure. Figure 8 , Figure 9 .Depend on Figure 8 The CV curves show that the assembled device has good stability; Figure 9 The charge-discharge curves of MoWN, MoN, and W were compared. 4.6 The capacitance of N4 can be calculated at a current density of 0.06 mA / cm². 2 At that time, its specific capacitance was 3.3 mF / cm. 2 2.9mF / cm 2 and 2.5mF / cm 2 .Depend on Figure 10 It can be seen that at 0.06 mA / cm 2 After 5000 cycles at the current density, the capacity retention rate is 90.8%. This is because the two-dimensional molybdenum-tungsten ternary nitride material of this invention has excellent conductivity and a stable nanosheet structure, and the synergistic effect of bimetallic ions provides more active sites, thus improving the capacitance performance of the material.

[0040] Example 2

[0041] The preparation method of the two-dimensional molybdenum-tungsten ternary nitride material in this embodiment includes the following steps:

[0042] (1) Weigh molybdenum disulfide, tungsten disulfide and sodium carbonate in a molar mass ratio of 1:1:6 into a mortar, add an appropriate amount of anhydrous ethanol and grind evenly to obtain a mixed powder, then transfer it to a porcelain boat; the molybdenum-tungsten raw material ratio must be kept uniform in order to obtain molybdenum-tungsten ternary nitride.

[0043] (2) Place the ceramic boat from step (1) into a tube furnace, heat it to 650°C at a heating rate of 5°C / min under an argon atmosphere and hold it for 1 hour, then heat it to 750°C at the same heating rate and switch to ammonia gas and hold it for 12 hours. The argon gas flow rate is 20 sccm and the ammonia gas flow rate is 100 sccm. Cool it to room temperature. The reason for first introducing argon gas and then ammonia gas is to prevent the raw material from reacting with ammonia gas before melting. First, introduce argon gas to heat it to 650°C to reach the melting point of the raw material so that it can be fully melted. Then introduce ammonia gas to heat it to 750°C to reach the nitriding temperature of the raw material and react with ammonia gas. Extend the holding time to 12 hours to still obtain a two-dimensional molybdenum-tungsten ternary nitride material with good morphology.

[0044] (3) Take out the product obtained in step (2) and put it into a centrifuge tube. Add 40 ml of hydrochloric acid with a concentration of 0.1 mol / L, put it in a centrifuge and centrifuge at a speed of 6000 r / min. Then add deionized water in the same way and centrifuge and clean it. After cleaning and drying, the two-dimensional molybdenum tungsten ternary nitride material is obtained.

[0045] In this embodiment, the heat preservation time was extended to 12 hours, and the morphology and XRD pattern of the obtained product are as follows. Figure 4 As shown, the two-dimensional molybdenum-tungsten ternary nitride material can still be obtained even with extended heat preservation time. Following the application example method, the two-dimensional molybdenum-tungsten ternary nitride material obtained in this embodiment was used as an electrode for a printed micro supercapacitor, and electrochemical characterization was performed. The results show that the obtained micro supercapacitor device achieves an efficiency of 0.06 mA / cm². 2 It has a current density of 4.6 mF / cm 2 The specific capacity retains 89.6% after 2000 cycles.

[0046] Example 3

[0047] The preparation method of the two-dimensional molybdenum-tungsten ternary nitride material in this embodiment includes the following steps:

[0048] (1) Weigh molybdenum disulfide, tungsten disulfide and sodium carbonate in a ratio of 1:1:6 and put them in a mortar. Add an appropriate amount of anhydrous ethanol and grind evenly to obtain a mixed powder. Transfer the powder to a porcelain boat. Only by keeping the ratio of molybdenum and tungsten raw materials uniform can molybdenum and tungsten ternary nitrides be obtained.

[0049] (2) Place the ceramic boat from step (1) into a tube furnace, heat it to 650°C at a heating rate of 5°C / min under an argon atmosphere and hold it for 1 hour, then heat it to 850°C at the same heating rate and switch to ammonia gas and hold it for 3 hours. The argon gas flow rate is 20 sccm and the ammonia gas flow rate is 100 sccm. Cool it to room temperature. The reason for first introducing argon gas and then ammonia gas is to prevent the raw material from reacting with ammonia gas before melting. First, introduce argon gas to heat it to 650°C to reach the melting point of the raw material so that it can be fully melted. Then, introduce ammonia gas to heat it to 850°C to reach the nitriding temperature of the raw material and react with ammonia gas. The ammonia gas reaction temperature is increased. A small number of particles appeared on the surface of the two-dimensional molybdenum-tungsten ternary nitride material. The reason is that the temperature rises to 850°C, causing some nanosheets to melt and agglomerate into particles.

[0050] (3) Take out the product obtained in step (2) and put it into a centrifuge tube. Add 40 ml of hydrochloric acid with a concentration of 0.1 mol / L, put it in a centrifuge and centrifuge at a speed of 6000 r / min. Then add deionized water in the same way and centrifuge and clean it. After cleaning and drying, the two-dimensional molybdenum tungsten ternary nitride material is obtained.

[0051] Figure 5 The SEM image from this embodiment shows a small number of particles in the obtained two-dimensional nanosheets. This is because the temperature increased to 850℃, causing some of the nanosheets to melt and agglomerate into particles. Following the application example method, the two-dimensional molybdenum-tungsten ternary nitride material obtained in this embodiment was used as an electrode for a printed micro supercapacitor, and electrochemical characterization was performed. The results show that the obtained micro supercapacitor device achieves an efficiency of 0.06 mA / cm². 2 It has a current density of 3.4 mF / cm 2 Specific capacity: after 2000 cycles, the capacity retention rate is 85.3%.

[0052] Comparative Example 1

[0053] The preparation method of the two-dimensional molybdenum-tungsten ternary nitride material in this comparative example includes the following steps:

[0054] (1) Weigh molybdenum disulfide, tungsten disulfide and sodium carbonate in a ratio of 1:1:6 and put them in a mortar. Add an appropriate amount of anhydrous ethanol and grind evenly to obtain a mixed powder. Transfer the powder to a porcelain boat.

[0055] (2) Place the ceramic boat from step (1) into a tube furnace, heat it to 550°C at a heating rate of 5°C / min under an ammonia atmosphere and hold it for 1 hour. The ammonia flow rate is 100 sccm. Cool it to room temperature.

[0056] (3) Take out the product obtained in step (2) and put it into a centrifuge tube. Add 40 ml of 0.1 mol / L hydrochloric acid and centrifuge at 6000 r / min. Then add deionized water and centrifuge again in the same way. After cleaning, dry to obtain the product.

[0057] Figure 6 (a) is a morphology diagram of the product obtained in this comparative example. A large number of blocky products are generated, indicating that ammonia gas is directly introduced before the melting temperature is reached, and the product reacts with ammonia gas in advance to directly generate nitrides. This shows that the growth of two-dimensional molybdenum-tungsten ternary nitrides must be carried out in a molten environment.

[0058] Comparative Example 2

[0059] The preparation method of the two-dimensional molybdenum-tungsten ternary nitride material in this comparative example includes the following steps:

[0060] (1) Weigh molybdenum disulfide, tungsten disulfide and sodium carbonate in a ratio of 1:1:6 and put them in a mortar. Add an appropriate amount of anhydrous ethanol and grind evenly to obtain a mixed powder. Transfer the powder to a porcelain boat.

[0061] (2) Place the ceramic boat from step (1) into a tube furnace, heat it to 650°C at a heating rate of 5°C / min under an argon atmosphere and hold it for 1 hour, then heat it to 950°C at the same heating rate and switch to ammonia gas to hold it for 3 hours, wherein the argon gas flow rate is 20 sccm and the ammonia gas flow rate is 100 sccm; cool it to room temperature.

[0062] (3) Take out the product obtained in step (2) and put it into a centrifuge tube. Add 40 ml of 0.1 mol / L hydrochloric acid and centrifuge at 6000 r / min. Then add deionized water and centrifuge again in the same way. After cleaning, dry the product to obtain the product.

[0063] Figure 6 (b) is a SEM image of the product obtained in this comparative example. After the temperature was increased to 950°C, the nanosheets melted and agglomerated into nanoparticles.

[0064] Comparative Example 3

[0065] Weigh molybdenum disulfide, tungsten disulfide and sodium carbonate in a ratio of 1:4:6 into a mortar, add an appropriate amount of anhydrous ethanol and grind evenly to obtain a mixed powder, then transfer it to a porcelain boat.

[0066] (2) Place the ceramic boat from step (1) into a tube furnace, heat it to 650°C at a heating rate of 5°C / min under an argon atmosphere and hold it for 1 hour, then heat it to 750°C at the same heating rate and switch to ammonia gas to hold it for 3 hours, wherein the argon gas flow rate is 20 sccm and the ammonia gas flow rate is 100 sccm; cool it to room temperature.

[0067] (3) Take out the product obtained in step (2) and put it into a centrifuge tube. Add 40 ml of 0.1 mol / L hydrochloric acid and centrifuge at 6000 r / min. Then add deionized water and centrifuge again in the same way. After cleaning, dry the product to obtain the product.

[0068] Figure 7 The XRD pattern of the product obtained in this comparative example shows that the product obtained after increasing the proportion of tungsten disulfide is W. 4.6 N4 indicates that an excessively high proportion of a certain raw material will prevent the formation of a bimetallic structure.

[0069] Based on the above embodiments, we explored the most suitable experimental conditions for preparing two-dimensional molybdenum-tungsten ternary nitride materials through Example 1, obtaining two-dimensional nanosheets with good conductivity and stable structure, which exhibited excellent specific capacitance and cycle stability in micro supercapacitor applications. Furthermore, the preparation method involved in this invention is simple, the raw material cost is low, which facilitates mass production, and its excellent capacitive properties demonstrate promising application prospects.

[0070] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A method for preparing a two-dimensional molybdenum-tungsten ternary nitride material, characterized in that, Includes the following steps: Step (1): Tungsten disulfide, molybdenum disulfide and sodium carbonate powder are directly and thoroughly ground to obtain a mixed powder with uniform particle size; Step (2): The obtained mixed powder is heated in an argon atmosphere to above the powder melting point temperature under an argon atmosphere to fully melt the raw materials. Then, ammonia gas is introduced to maintain the temperature at the specified temperature. Finally, the mixture is cooled to room temperature to obtain the black product. Step (3): The obtained black product is subjected to acid washing and water washing treatment; Step (4): Place the washed product in a freeze dryer for drying.

2. The method for preparing two-dimensional molybdenum-tungsten ternary nitride materials according to claim 1, characterized in that, In step (1), the molar mass ratio of tungsten disulfide, molybdenum disulfide, and sodium carbonate is 1:1:

6.

3. The method for preparing two-dimensional molybdenum-tungsten ternary nitride materials according to claim 1, characterized in that, The heating rate in step (2) is 5℃ / min.

4. The method for preparing two-dimensional molybdenum-tungsten ternary nitride materials according to claim 1, characterized in that, In step (2), the argon gas flow rate is 50 sccm and the ammonia gas flow rate is 100 sccm.

5. The method for preparing two-dimensional molybdenum-tungsten ternary nitride materials according to claim 1, characterized in that, In step (2), the argon gas insulation temperature is 650℃ and the insulation time is 1h, while the ammonia gas insulation temperature is 750-850℃ and the insulation time is 3-12h.

6. The preparation method according to claim 1, characterized in that, Pickling and washing are performed by centrifugation at a speed of 6000 r / min.

7. The preparation method according to claim 1, characterized in that, The acid used for pickling is 0.1 mol / L hydrochloric acid.

8. A two-dimensional molybdenum-tungsten ternary nitride material, prepared by the method for preparing two-dimensional molybdenum-tungsten ternary nitride materials according to claim 1, characterized in that: The two-dimensional molybdenum-tungsten ternary nitride material is a two-dimensional nanosheet structure with molybdenum-tungsten bimetallic components, and the nanosheet size is 1-3 μm.

9. A supercapacitor electrode material, which is prepared by the method for preparing two-dimensional molybdenum-tungsten ternary nitride material as described in claim 1.

10. Electrode materials for supercapacitors, characterized by: The material is the two-dimensional molybdenum-tungsten ternary nitride material as described in claim 8.

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