Nickel-based perovskite fluoride composite electrode material and preparation method and application thereof
By constructing a heterostructure of KNiF3 and NiAl-LDH, the problems of insufficient cycle stability and specific surface area of perovskite fluoride electrode materials in supercapacitors were solved, and a nickel-based perovskite fluoride composite electrode material with high specific capacitance and good cycle stability was realized.
Patent Information
- Application Number
- CN202511746445.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-26
- Publication Date
- 2026-01-13
AI Technical Summary
Existing perovskite fluoride electrode materials have low cycling stability and small specific surface area in supercapacitors, which limits their application in high-performance supercapacitors.
A two-step solvothermal method was used to construct a heterostructure of KNiF3 and NiAl-LDH. NiAl-LDH was used as a substrate to provide a large specific surface area and nucleation sites, which promoted the uniform growth and dispersion of KNiF3 nanoparticles, thus forming a nickel-based perovskite fluoride composite electrode material KNiF3@NiAl-LDH.
It improves the specific capacitance and cycle stability of the electrode material, exhibiting high specific capacitance and good cycle stability, suppressing structural collapse during charge and discharge, and promoting rapid diffusion and transport of electrolyte ions.
Smart Images
Figure CN121331669A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrode materials technology, and in particular to a nickel-based perovskite fluoride composite electrode material, its preparation method, and its application. Background Technology
[0002] With the continued depletion of fossil fuels and the escalating environmental pollution, there is an urgent need to find renewable energy sources. To overcome the temporal and spatial limitations of renewable energy, the development of advanced energy conversion and storage devices has become a research hotspot for teams worldwide. Supercapacitors, as energy storage devices with rapid charging and discharging, ultra-long cycle stability, and high power density, have attracted considerable attention.
[0003] To meet the ever-increasing energy density demands of applications, it is necessary to improve the performance of supercapacitors. Common supercapacitor electrode materials fall into three categories: carbon materials, transition metal compounds, and conductive polymers, corresponding to double-layer and pseudocapacitive types, respectively. Compared to carbon materials and conductive polymers, transition metal compounds exhibit higher specific capacitance and cycle stability. Perovskite fluorides, due to their high theoretical capacity (approximately 177 mAh·g), are also promising candidates. -1 While it has gradually gained attention, its low cycle stability and small specific surface area limit its large-scale application in high-performance supercapacitors. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and propose a nickel-based perovskite fluoride composite electrode material, its preparation method, and its application. This invention can produce a composite material with good crystallinity, a large specific surface area, and a heterogeneous structure that can activate surface active sites, resulting in greater activity. The open structural framework can suppress structural collapse caused by expansion, thus enhancing cycle stability. At the same time, the numerous pores facilitate the transport and transfer of electrolyte ions, thereby improving the electrochemical performance of supercapacitors.
[0005] To achieve the above objectives, the present invention adopts the following specific technical solution:
[0006] The method for preparing the nickel-based perovskite fluoride composite electrode material provided by the present invention includes the following steps:
[0007] Step 1: Dissolve the soluble nickel salt, aluminum salt, ammonium fluoride, and urea in ethanol to form a mixed solution;
[0008] Step 2: The obtained mixed solution is subjected to a first solvothermal reaction. After the reaction, it is cooled, centrifuged, dried and ground to obtain nickel-aluminum layered double hydroxide NiAl-LDH.
[0009] Step 3: The prepared NiAl-LDH is ultrasonically dispersed in an ethylene glycol solution containing soluble nickel salt and potassium fluoride to form a suspension;
[0010] Step 4: The obtained suspension is subjected to a second solvothermal reaction. After the reaction, it is cooled, centrifuged, dried and ground to obtain the nickel-based perovskite fluoride composite nickel-based layered double hydroxide electrode material KNiF3@NiAl-LDH.
[0011] Furthermore, in step one, the molar ratio of soluble nickel salt, aluminum salt, ammonium fluoride, and urea is 3:1:7-10:18-24.
[0012] Furthermore, in step two, the temperature of the first solvothermal reaction is 100–130°C, and the reaction time is 12–24 hours; in step four, the temperature of the second solvothermal reaction is 150–160°C, and the reaction time is 8 hours.
[0013] Furthermore, in step three, the molar ratio of soluble nickel salt to potassium fluoride is 1:2.8 to 3.2.
[0014] Furthermore, soluble nickel salts are selected from nickel nitrate or nickel chloride; aluminum salts are selected from aluminum nitrate or aluminum chloride.
[0015] Furthermore, in steps one and three, the dissolution and dispersion processes are carried out sequentially under stirring and ultrasonic conditions; the stirring speed is 3000-4000 r / min and the time is 0.5-1 hour; the ultrasonic power is 80-100 W and the time is 0.5-1 hour.
[0016] Furthermore, in steps two and four, the centrifugation speed is 8000-10000 r / min and the time is 10-20 minutes; the drying is carried out by forced air drying at a temperature of 60℃. Specifically, the drying time of NiAl-LDH in step two is 24-36 hours, and the drying time of KNiF3@NiAl-LDH in step four is 12-20 hours.
[0017] The nickel-based perovskite fluoride composite electrode material provided by the present invention is prepared by the above-described preparation method.
[0018] The application of the nickel-based perovskite fluoride composite electrode material provided by this invention in the preparation of supercapacitors.
[0019] The present invention can achieve the following technical effects:
[0020] The present invention provides a two-step solvothermal method for constructing a heterostructure of KNiF3 and NiAl-LDH. NiAl-LDH, as a substrate, provides a large specific surface area and abundant nucleation sites, promoting the uniform growth and dispersion of KNiF3 nanoparticles and effectively inhibiting aggregation. The composite material combines the advantages of high theoretical capacity of KNiF3 and high specific surface area of NiAl-LDH. The synergistic effect at the heterostructure interface activates more electrochemical active sites, while the open framework structure facilitates rapid diffusion and transport of electrolyte ions. The prepared composite material exhibits high specific capacitance (up to 1621 F / g at a current density of 1 A / g) and good cycling stability (capacity retention of 71.35% after 4000 cycles at a current density of 10 A / g). The supporting effect of NiAl-LDH effectively buffers the volume expansion of KNiF3 during charge and discharge, inhibiting structural collapse. The preparation method used in this invention is relatively simple, the process is mature, the parameters are easy to control, and the raw materials used are inexpensive and readily available, making it suitable for large-scale production. Attached Figure Description
[0021] Figure 1 This is a flowchart of a method for preparing a nickel-based perovskite fluoride composite electrode material according to an embodiment of the present invention;
[0022] Figure 2 This is a scanning electron microscope image of the KNiF3@NiAl-LDH electrode material prepared according to Example 1 of the present invention;
[0023] Figure 3 This is an X-ray diffraction pattern of the KNiF3@NiAl-LDH electrode material prepared according to Example 1 of the present invention;
[0024] Figure 4 This is a constant current charge-discharge curve of the KNiF3@NiAl-LDH electrode material prepared according to Example 1 of the present invention;
[0025] Figure 5 This is a cycle stability curve of the KNiF3@NiAl-LDH electrode material prepared according to Example 1 of the present invention;
[0026] Figure 6 This is a nitrogen adsorption-desorption curve of the KNiF3@NiAl-LDH electrode material prepared according to Example 1 of the present invention;
[0027] Figure 7 This is a scanning electron microscope image of the KNiF3@NiAl-LDH electrode material prepared according to Example 2 of the present invention;
[0028] Figure 8This is the Ni2p orbital photoelectron spectrum of the KNiF3@NiAl-LDH electrode material prepared according to Example 1 of the present invention;
[0029] Figure 9 This is a scanning electron microscope image of the KNiF3@NiAl-LDH electrode material prepared according to Comparative Example 1 of the present invention. Detailed Implementation
[0030] In the following description, embodiments of the invention will be described with reference to the accompanying drawings. In the description below, the same modules are denoted by the same reference numerals. Where the same reference numerals are used, their names and functions are also the same. Therefore, their detailed description will not be repeated.
[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.
[0032] This invention provides a method for preparing a nickel-based perovskite fluoride composite electrode material, the process of which is as follows: Figure 1 As shown, it includes the following steps:
[0033] Step 1: Dissolve the soluble nickel salt, aluminum salt, ammonium fluoride, and urea in ethanol to form a mixed solution;
[0034] Step 2: The obtained mixed solution is subjected to a first solvothermal reaction. After the reaction, it is cooled, centrifuged, dried and ground to obtain nickel-aluminum layered double hydroxide NiAl-LDH.
[0035] Step 3: The prepared NiAl-LDH is ultrasonically dispersed in an ethylene glycol solution containing soluble nickel salt and potassium fluoride to form a suspension;
[0036] Step 4: The obtained suspension is subjected to a second solvothermal reaction. After the reaction, it is cooled, centrifuged, dried and ground to obtain the nickel-based perovskite fluoride composite nickel-based layered double hydroxide electrode material KNiF3@NiAl-LDH.
[0037] The preparation method will be described below with reference to specific examples.
[0038] Example 1
[0039] A method for preparing a KNiF3@NiAl-LDH composite electrode material includes the following steps;
[0040] Step 1: Under stirring conditions, add 58 mg of nickel nitrate, 25 mg of aluminum nitrate, 296 mg of ammonium fluoride and 1201 mg of urea to 32 ml of ethanol solution to obtain a homogeneous solution.
[0041] Step 2: Add the mixed solution from Step 1 to a stainless steel autoclave with a Teflon liner containing 40 ml of liquid and maintain the reaction at 120°C for 20 h. Then, allow the autoclave to cool naturally to room temperature, collect the sample and wash it several times. After centrifugation, drying and grinding, NiAl-LDH is obtained.
[0042] Step 3: Place the NiAl-LDH obtained in Step 2 into 28 ml of ethylene glycol and disperse it. Then add 166 mg of nickel chloride and 184 mg of potassium fluoride to the solvent and stir ultrasonically to form a uniform suspension.
[0043] Step 4: Add the suspension obtained in Step 3 to a stainless steel autoclave with a Teflon liner containing 40 ml of liquid and maintain the reaction at 160°C for 8 hours. Then, allow the autoclave to cool naturally to room temperature, collect the sample and wash it several times. After centrifugation, drying and grinding, the KNiF3@NiAl-LDH electrode material is obtained.
[0044] Example 2
[0045] A method for preparing a KNiF3@NiAl-LDH composite electrode material includes the following steps;
[0046] Step 1: Under stirring conditions, add 69 mg of nickel nitrate, 30 mg of aluminum nitrate, 390 mg of ammonium fluoride and 1585 mg of urea to 32 ml of ethanol solution to obtain a homogeneous solution.
[0047] Step 2: Add the mixed solution from Step 1 to a stainless steel autoclave with a Teflon liner containing 40 ml of liquid and maintain the reaction at 110°C for 24 h. Then, allow the autoclave to cool naturally to room temperature, collect the sample and wash it several times. After centrifugation, drying and grinding, NiAl-LDH is obtained.
[0048] Step 3: Place the LDH obtained in Step 2 into 28 ml of ethylene glycol and disperse it. Then add 182 mg of nickel chloride and 223 mg of potassium fluoride to the solvent and stir ultrasonically to form a uniform suspension.
[0049] Step 4: Add the suspension obtained in Step 3 to a stainless steel autoclave with a Teflon liner containing 40 ml of liquid and maintain the reaction at 150°C for 8 hours. Then, allow the autoclave to cool naturally to room temperature, collect the sample and wash it several times. After centrifugation, drying and grinding, the KNiF3@NiAl-LDH electrode material is obtained.
[0050] Example 3
[0051] A method for preparing a KNiF3@NiAl-LDH composite electrode material includes the following steps;
[0052] Step 1: Under stirring conditions, add 52 mg of nickel nitrate, 23 mg of aluminum nitrate, 253 mg of ammonium fluoride and 1027 mg of urea to 32 ml of ethanol solution to obtain a homogeneous solution.
[0053] Step 2: Add the mixed solution from Step 1 to a stainless steel autoclave with a Teflon liner containing 40 ml of liquid and maintain the reaction at 130°C for 12 h. Then, allow the autoclave to cool naturally to room temperature, collect the sample and wash it several times. After centrifugation, drying and grinding, NiAl-LDH is obtained.
[0054] Step 3: Place the LDH obtained in Step 2 into 28 ml of ethylene glycol and disperse it. Then add 223 mg of nickel chloride and 248 mg of potassium fluoride to the solvent and stir ultrasonically to form a uniform suspension.
[0055] Step 4: Add the suspension obtained in Step 3 to a stainless steel autoclave with a Teflon liner containing 40 ml of liquid and maintain the reaction at 155°C for 8 hours. Then, allow the autoclave to cool naturally to room temperature, collect the sample and wash it several times. After centrifugation, drying and grinding, the KNiF3@NiAl-LDH electrode material is obtained.
[0056] Comparative Example 1
[0057] A method for preparing a KNiF3@NiAl-LDH composite electrode material includes the following steps;
[0058] Step 1: Under stirring conditions, add 58 mg of nickel nitrate, 25 mg of aluminum nitrate, 296 mg of ammonium fluoride and 1201 mg of urea to 32 ml of ethanol solution to obtain a homogeneous solution.
[0059] Step 2: Add the mixed solution from Step 1 to a stainless steel autoclave with a Teflon liner containing 40 ml of liquid and maintain the reaction at 120°C for 20 h. Then, allow the autoclave to cool naturally to room temperature, collect the sample and wash it several times. After centrifugation, drying and grinding, NiAl-LDH is obtained.
[0060] Step 3: Place the LDH obtained in Step 2 into 28 ml of ethylene glycol and disperse it. Then add 332 mg of nickel chloride and 368 mg of potassium fluoride to the solvent and stir ultrasonically to form a uniform suspension.
[0061] Step 4: Add the suspension obtained in Step 3 to a stainless steel autoclave with a Teflon liner containing 40 ml of liquid and maintain the reaction at 160°C for 8 hours. Then, allow the autoclave to cool naturally to room temperature, collect the sample and wash it several times. After centrifugation, drying and grinding, the KNiF3@NiAl-LDH electrode material is obtained.
[0062] The preparation steps of Comparative Example 1 are the same as those of Example 1, except that the amounts of potassium fluoride and nickel chloride in step 3 are replaced by 368 mg and 332 mg, respectively, instead of 184 mg and 166 mg.
[0063] Figure 2 This is a scanning electron microscope image of the KNiF3@NiAl-LDH electrode material prepared in Example 1. Figure 2 It can be seen that the electrode material is a self-assembled sheet-like microsphere wrapped with nanoparticles, with a sufficient porosity structure.
[0064] Figure 3 This is the X-ray diffraction pattern of the KNiF3@NiAl-LDH electrode material prepared in Example 1. Figure 3 It can be seen that the diffraction peaks of the KNiF3@NiAl-LDH electrode material correspond one-to-one with the standard card, indicating that no other impurities are generated, which means that a homogeneous phase with high crystallinity has been synthesized.
[0065] Figure 4 The figure shows the galvanostatic charge-discharge curve of the KNiF3@NiAl-LDH electrode material prepared in Example 1. Calculations show that the material has a specific capacitance of 1621 F / g at a current density of 1 A / g, indicating that it has high capacitance performance and also proving that the material has good electrochemical performance.
[0066] Figure 5 The figure shows the cycling stability curve of the KNiF3@NiAl-LDH electrode material prepared in Example 1. Calculations show that the material retains 71.35% of its capacity after 4000 cycles at a current density of 10 A / g, indicating good cycling stability and demonstrating its excellent electrochemical performance.
[0067] Figure 6 The image shows the nitrogen adsorption-desorption curve of the KNiF3@NiAl-LDH electrode material prepared in Example 1. The test results show that this material has a nitrogen adsorption-desorption capacity of 70.9 μm. 2 The high specific surface area of / g indicates that this material has a large specific surface area and more active sites.
[0068] Figure 7 This is a scanning electron microscope image of the KNiF3@NiAl-LDH electrode material prepared in Example 2. Figure 7It can be seen that the electrode material is a self-assembled sheet-like microsphere wrapped with nanoparticles, with a sufficient porosity structure.
[0069] Figure 8 This is the Ni2p orbital photoelectron spectrum of the KNiF3@NiAl-LDH electrode material prepared in Example 1. Peak fitting reveals the Ni... 2+ The peak center is at 855.58 eV, Ni 3+ The peak center is at 862.49 eV. The value of Ni can be determined by calculating the peak area. 2+ / Ni 3+ The ratio is 1.71:1.
[0070] Figure 9 This is a scanning electron microscope image of the KNiF3@NiAl-LDH electrode material prepared in Comparative Example 1. Figure 9 It can be seen that the electrode material consists of excessive nanoparticles encapsulating sheet-like microspheres. The particles aggregate with each other, blocking the pores inside the material. This indicates that although the synthesis method of Comparative Example 1 can synthesize KNiF3@NiAl-LDH electrode material, the excessive composite of KNiF3 leads to the accumulation of material, reducing the specific surface area and which is detrimental to the electrochemical performance of the material.
[0071] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0072] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
[0073] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.
Claims
1. A method for preparing a nickel-based perovskite fluoride composite electrode material, characterized in that, Includes the following steps: Step 1: Dissolve the soluble nickel salt, aluminum salt, ammonium fluoride, and urea in ethanol to form a mixed solution; Step 2: The obtained mixed solution is subjected to a first solvothermal reaction. After the reaction, it is cooled, centrifuged, dried and ground to obtain nickel-aluminum layered double hydroxide NiAl-LDH. Step 3: The prepared NiAl-LDH is ultrasonically dispersed in an ethylene glycol solution containing soluble nickel salt and potassium fluoride to form a suspension; Step 4: The obtained suspension is subjected to a second solvothermal reaction. After the reaction, it is cooled, centrifuged, dried and ground to obtain the nickel-based perovskite fluoride composite nickel-based layered double hydroxide electrode material KNiF3@NiAl-LDH.
2. The method for preparing the nickel-based perovskite fluoride composite electrode material according to claim 1, characterized in that, In step one, the molar ratio of the soluble nickel salt, aluminum salt, ammonium fluoride, and urea is 3:1:7-10:18-24.
3. The method for preparing the nickel-based perovskite fluoride composite electrode material according to claim 1, characterized in that, In step two, the temperature of the first solvothermal reaction is 100-130°C and the reaction time is 12-24 hours; in step four, the temperature of the second solvothermal reaction is 150-160°C and the reaction time is 8 hours.
4. The method for preparing the nickel-based perovskite fluoride composite electrode material according to claim 1, characterized in that, In step three, the molar ratio of the soluble nickel salt to potassium fluoride is 1:2.8 to 3.
2.
5. The method for preparing the nickel-based perovskite fluoride composite electrode material according to claim 1, characterized in that, The soluble nickel salt is selected from nickel nitrate or nickel chloride; the aluminum salt is selected from aluminum nitrate or aluminum chloride.
6. The method for preparing the nickel-based perovskite fluoride composite electrode material according to claim 1, characterized in that, In steps one and three, the dissolution and dispersion processes are carried out sequentially under stirring and ultrasonic conditions; the stirring speed is 3000-4000 r / min and the time is 0.5-1 hour; the ultrasonic power is 80-100 W and the time is 0.5-1 hour.
7. The method for preparing the nickel-based perovskite fluoride composite electrode material according to claim 1, characterized in that, In steps two and four, the centrifugation speed is 8000-10000 r / min and the time is 10-20 minutes; the drying is carried out using forced air drying at a temperature of 60℃. Specifically, the drying time for NiAl-LDH in step two is 24-36 hours, and the drying time for KNiF3@NiAl-LDH in step four is 12-20 hours.
8. A nickel-based perovskite fluoride composite electrode material, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 7.
9. The application of the nickel-based perovskite fluoride composite electrode material as described in claim 8 in the preparation of supercapacitors.