Synthesis of nickel diselenide nanoparticles with high specific capacitance
By synthesizing nickel diselenide nanoparticles through wet chemical methods, the problem of low specific capacitance of carbon material supercapacitor electrode materials was solved, electrode materials with high specific capacitance and good cycle stability were achieved, and the application of nickel-based materials in new energy storage systems was expanded.
Patent Information
- Application Number
- CN202510840907.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-23
- Publication Date
- 2025-09-19
AI Technical Summary
When existing carbon materials are used as supercapacitor electrode materials, they have the problem of low specific capacitance performance and are difficult to meet the needs of practical applications.
Nickel diselenide nanoparticles with uniform morphology were synthesized by wet chemical method as supercapacitor electrode materials. Nanoparticles with high specific capacitance characteristics were prepared by controlling the ratio of nickel and selenium and the reaction conditions.
It has achieved a significant improvement in specific capacitance performance, which is higher than the specific capacitance characteristics of carbon materials, has good cycle stability and electrochemical properties, and is suitable for electrode materials of supercapacitors.
Smart Images
Figure CN120664503A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of new energy materials, and in particular relates to a wet chemical synthesis of nickel diselenide nanoparticles with high specific capacitance. Background Art
[0002] Supercapacitors are a new type of environmentally friendly energy storage device, boasting high power density, long cycle life, rapid charge and discharge, and high reliability. They hold broad application prospects in mobile communications, aerospace, electric vehicles, and national defense. In recent years, with the continuous advancement of supercapacitor research and the rapid development of related technology industries, their application areas are continuously expanding, and the market prospects are very promising. Electrode materials are key to supercapacitors, determining key performance indicators of these energy storage devices, such as energy density, power density, and cycle stability.
[0003] Therefore, it is crucial to develop environmentally friendly and low-cost electrode materials. Among the various electrode materials, porous carbon materials have attracted much attention due to their advantages such as low cost, good electrochemical stability, strong conductivity, and large specific surface area, and have been commercialized. Among them, activated carbon is the most widely used supercapacitor electrode active material. It has a high specific surface area and relatively low cost, and its specific capacitance is usually 100-300 F g -1 (Advanced Materials, 2011, 23, 42, 4828-4850). Other carbon materials, such as carbon nanotubes, graphene, porous carbon materials, carbon aerogels, and carbon black, usually have specific capacitances lower than 500 F g -1 However, the energy density of carbon-based supercapacitors is still relatively low, about 1 / 20 of that of commercial lithium-ion batteries, which is difficult to meet the needs of practical applications.
[0004] Compared with carbon materials, nickel materials (such as nickel hydroxide, nickel oxide and nickel-based composite materials) have good specific capacitance performance and cycle stability in supercapacitors. They are often used as electrode materials and have become a popular choice for supercapacitor electrode materials. However, the poor conductivity and cycle stability of nickel oxide limit its practical application. In order to solve this problem, researchers at home and abroad have conducted a lot of exploration. For example, the specific capacity of Ni(OH)2 mixture based on Mg(OH)2 is 167F g -1 When Ni(OH)2 is mixed with nitrogen-doped multi-walled carbon nanotube nanocomposites, its supercapacitor performance can be improved to 350F g -1 (ACS Energy Lett. 2016, 1, 4, 814–819; Sci Rep, 2019, 9, 6034). Therefore, an effective strategy is needed to achieve higher specific capacity and better long-term stability.
[0005] This study uses transition metal nickel and selenium as precursors to synthesize uniform nickel diselenide nanoparticles via a solution method, achieving higher specific capacitance than single-metal nickel nanoparticles. The excellent performance of nickel diselenide nanoparticles stems from their uniform particle size and small nanometer scale, which facilitates contact between electrolyte ions and active materials, thereby increasing material utilization. This result theoretically demonstrates the feasibility of nickel-based materials for capacitor applications, addressing technical issues such as the low capacitance of carbon materials used as supercapacitors and providing new opportunities for the use of nickel-based materials in novel energy storage systems. Summary of the Invention
[0006] The present invention aims to provide a method for preparing nickel diselenide nanoparticles for use as supercapacitor electrode materials, so as to solve the technical problem of low capacity of carbon materials as supercapacitors.
[0007] To solve the above technical problems, the present invention provides a new method for synthesizing monodisperse and uniform nickel selenide nanoparticles using a wet chemical method for determining supercapacitor materials in alkaline solution. The specific technical solution mainly includes the following steps:
[0008] (1) Slurry preparation: In an argon-filled glove box, 0.4 mM Ni(acac)2(nickel(II)acetylacetonate (Ni(acac)2, 96%, Sigma Aldrich) and 8 mM Se powder (Se, 200 mesh, 99.5%, Acros Organics) were dissolved in 30 mL of 0Am(oleylamine, C 18 H 37 N, 80-90%, AcrosOrganics) and 3mL DDT (1-dodecanethiol, CH3(CH2) 11 SH) in a bottle, stirring at 50° C. for 1 hour, and then filtering the obtained solution through a 0.2 μm filter to prepare a uniformly mixed precursor slurry;
[0009] (2) Heating reaction: Next, in a 150 mL three-necked flask, 10 mL of the prepared precursor solution and 60 mL of OAm were placed in a vacuum and treated at 60 °C for 30 min. Then, the mixture was heated to 220 °C at a rate of 5 °C / min under an Ar atmosphere. After reacting for 20 min, the solution was quickly cooled to room temperature.
[0010] (3) Washing and drying: The solution was mixed with 60 mL of chloroform and then centrifuged at 8000 rpm for 5 minutes. The dispersion in chloroform / ethanol and the centrifugal washing process were repeated three times. Finally, the obtained product was dried in a vacuum at 60°C for 12 hours and properly stored for future use.
[0011] Furthermore, in step (1), the Ni(acac)2 and Se powders required for slurry preparation are 0.4 mM and 0.8 mM respectively.
[0012] Furthermore, it is characterized in that, in the step (1), the OAm and EDT required for slurry preparation are 30 mL and 3 mL respectively.
[0013] Furthermore, it is characterized in that, in the step (2), the amount of slurry required for the heating reaction is 10 mL; the amount of OAm is 60 mL.
[0014] Furthermore, it is characterized in that in step (2), the heating reaction conditions are vacuum treatment at 60°C for 30 minutes, then heating to 220°C at a rate of 5°C / min under Ar atmosphere, and reacting for 20 minutes.
[0015] Furthermore, it is characterized in that in step (3), the washing and drying conditions are: first, the solution is mixed with 60 mL of chloroform and then centrifuged at 8000 rpm for 5 minutes, and the washing centrifugation process is repeated 3 times. Finally, the obtained product is dried in a vacuum at 60° C. for 12 hours and stored for use.
[0016] The preparation method of nickel diselenide particles provided by the present invention has the characteristics of uniform morphology and higher specific capacitance characteristics than carbon materials; this simple material synthesis method has broad prospects in sustainable energy and environmental applications. DETAILED DESCRIPTION
[0017] In order to better understand the purpose of the present invention, the structure and function of the synthetic nanomaterial, the following is a further description of the synthetic wet chemical preparation method of nickel diselenide nanoparticles for supercapacitor electrode materials and their capacitance performance in conjunction with the accompanying drawings.
[0018] Based on this, the inventors used nickel and selenium as raw materials to precisely control the synthesis of nickel diselenide (NiSe2) nanomaterials. Figure 1 As shown, the synthesis is divided into three steps: slurry preparation, heating reaction, washing and drying. The specific process is as follows:
[0019] First, slurry preparation: In an argon-filled glove box, 0.4 mM Ni(acac)2 and 8 mM Se powder were dissolved in a bottle containing 30 mL OAm and 3 mL DDT, stirred at 50 °C for 1 h, and then the obtained solution was filtered through a 0.2 μm filter to prepare a well-mixed precursor slurry;
[0020] Secondly, heating reaction: Next, in a 150 mL three-necked flask, 10 mL of the prepared precursor solution and 60 mL of OAm were placed together in vacuum and treated at 60 °C for 30 min, and then heated to 220 °C at a rate of 5 °C / min under Ar atmosphere. After reacting for 20 minutes, the solution was quickly cooled to room temperature;
[0021] Finally, washing and drying: the solution was mixed with 60 mL of chloroform and then centrifuged at 8000 rpm for 5 minutes. The dispersion and centrifugal washing process in chloroform / ethanol was repeated three times. Finally, the obtained product was dried in a vacuum at 60 ° C for 12 hours and properly stored for use.
[0022] Physical characterization of the dried material was performed to determine the physical and chemical properties of the obtained material.
[0023] First, XRD is used to determine the structure of the obtained material. Figure 2 As shown in a, its crystal form is consistent with the NiSe2 standard card and has the structure of NiSe2. Figure 2 The TEM image in b shows that the nanomaterial has the morphology of nanoparticles with a particle size of 37.6±7.4nm.
[0024] Figure 3 3 is a SEM-EDS image of the nickel diselenide nanoparticles of the present invention, wherein the atomic content ratio of NiS is 32.7%, which is consistent with the Ni / Se ratio of 1 / 2.
[0025] In order to compare the electrochemical properties with those of single metal Ni, we prepared Ni single substance nanoparticles by the following method: a magnetic bar, 1mM nickel acetylacetonate (Ni(C5H7O2)2), 2.7mL oleylamine (C 18 H 35 -NH2), 0.4 mM trioctylphosphine (P(C8H 17 )2) and 0.25 mM trioctylphosphine oxide (OP(C8H 17 2) Maintain the mixture under vacuum at 130°C for 30 minutes. After introducing argon for protection, the temperature was rapidly raised to 215°C and maintained at this temperature for 45 minutes. The flask was then cooled to room temperature in a water bath. Ethanol was added and the mixture was centrifuged to separate the black precipitate. Finally, the mixture was dried under vacuum and set aside.
[0026] Figure 4 1 and 2 are XRD and TEM images of nickel nanoparticles used as a comparative sample of the present invention, and the average particle size thereof is 9.6±0.9 nm.
[0027] The performance test of the electrochemical supercapacitor was carried out with the help of an electrochemical workstation, using a three-electrode system with a glassy carbon electrode as the working electrode, a Pt wire as the counter electrode, and Hg / HgO as the reference electrode. The preparation process of the working electrode slurry is as follows: 5mg of nanoparticle sample and 10mg of carbon black are dissolved in 1mL of deionized water, 1mL of ethanol, and 0.1mL of Nafion. After ultrasonic stirring for 1 hour, 5uL of the newly prepared electrocatalyst slurry is extracted with a pipette and dropped onto a glassy carbon electrode with a diameter of 5mm. The sample is allowed to dry naturally before the electrochemical test.
[0028] Galvanostatic charge-discharge (GCD) curves were used to evaluate the supercapacitor performance of nickel diselenide and nickel nanoparticles.
[0029] Figure 5 The nickel diselenide nanoparticles of the present invention ( Figure 5 a) and nickel nanoparticles ( Figure 5 b) Charge-discharge curves of the electrode in 1M KOH at a variable current of 0.05-1.0 mA in the Hg / HgO potential window of 0-0.6 V.
[0030] From the GCD curve, the specific capacity (C) can be calculated using the following equation:
[0031]
[0032] Where I is the charge or discharge current, Δt is the charge and discharge time, m is the mass of Ni-Co nanoparticles deposited on the electrode, and ΔV is the potential window used for the test.
[0033] According to the GCD curve and the above formula, the charge and discharge capacitance of the nickel diselenide nanomaterial electrode at currents of 0.1, 0.3, 0.5, 0.7, and 1.0 mA is 832.8, 747.5, 707.1, 691.4, and 673.4 F g -1 , which are higher than the specific capacity of the Ni nanoparticles electrode (680.1, 558.9, 493.8, 455.7, 448.9 F g -1 ).
[0034] Cycling performance is another important parameter of supercapacitors. Figure 6The specific capacity of nickel diselenide electrode after 500 cycles at 0.5 mA current is shown. As can be seen from the figure, at this current, the initial specific capacity is about 850 F g -1 As the cycle progresses, the specific capacity gradually decreases to 465 F g after the 500th cycle. -1 The Coulombic efficiency of the entire process is about 95%.
[0035] Overall, the nickel diselenide nanoparticle-based electrode has a relatively high specific capacity and cycling performance, indicating its application potential. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Figure 1 The figure is a schematic flow chart of the wet chemical preparation method for synthesizing nickel diselenide nanoparticles of the present invention.
[0037] Figure 2 The figures are XRD, TEM and particle size distribution of nickel diselenide nanoparticles of the present invention.
[0038] Figure 3 This is a SEM-EDS image of the nickel diselenide nanoparticles of the present invention.
[0039] Figure 4 The XRD, TEM and particle size distribution diagrams of the nickel nanoparticles used as a comparative sample of the present invention are shown.
[0040] Figure 5 These are GCD diagrams of (a) nickel diselenide nanoparticles and (b) nickel nanoparticles of the present invention at different charge and discharge currents.
[0041] Figure 6 The specific capacitance and coulombic efficiency cycle performance of the nickel diselenide nanoparticles of the present invention are shown.
Claims
1. A wet chemical synthesis method for nickel diselenide nanoparticles with high specific capacitance, comprising the following steps: (1) Slurry preparation: In an argon-filled glove box, 0.4 mM Ni(acac)2 and 8 mM Se powder were dissolved in a bottle containing 30 mL OAm and 3 mL DDT, stirred at 50 °C for 1 h, and then the obtained homogeneous precursor slurry was filtered through a 0.2 μm filter; (2) Heating reaction: Next, in a 150 mL three-necked flask, 10 mL of the prepared precursor solution and 60 mL of OAm were placed in a vacuum, vacuum treated at 60 °C for 30 min, and then heated to 220 °C at a rate of 5 °C / min under an Ar atmosphere. After reacting for 20 min, the solution was quickly cooled to room temperature; (3) Washing and drying: The solution was mixed with 60 mL of chloroform and then centrifuged at 8000 rpm for 5 minutes. The dispersion in chloroform / ethanol and the centrifugal washing process were repeated three times. Finally, the obtained product was dried in a vacuum at 60°C for 12 hours and properly stored for future use.
2. The wet chemical synthesis method of nickel diselenide nanoparticles for supercapacitors according to claim 1, characterized in that: In step (1), the amounts of Ni(acac)2 and Se powder required for slurry preparation are 0.4 mM and 0.8 mM, respectively.
3. The wet chemical synthesis method of nickel diselenide nanoparticles for supercapacitors according to claim 2, characterized in that: In the step (1), the OAm and DDT required for slurry preparation were 30 mL and 3 mL, respectively.
4. The wet chemical synthesis method of nickel diselenide nanoparticles for supercapacitors according to claim 3, characterized in that: In the step (2), the amount of slurry required for the heating reaction is 10 mL; the amount of OAm is 60 mL.
5. The wet chemical synthesis method of nickel diselenide nanoparticles for supercapacitors according to claim 4, characterized in that: In the step (2), the heating reaction conditions are vacuum treatment at 60° C. for 30 minutes, then heating to 220° C. at a rate of 5° C. / min under an Ar atmosphere and reacting for 20 minutes.
6. The wet chemical synthesis method of nickel diselenide nanoparticles for supercapacitor electrode materials according to claim 5, characterized in that: In step (3), the washing and drying conditions are as follows: first, the solution is mixed with 60 mL of chloroform and then centrifuged at 8000 rpm for 5 minutes, and this process is repeated 3 times. Finally, the obtained product is dried in a vacuum at 60° C. for 12 hours and stored for use.