Preparation method of NiCo layered double hydroxide and application of NiCo layered double hydroxide in aqueous zinc battery
By optimizing the preparation process of NiCo-LDH, a highly controllable hierarchical structure is formed, which solves the problems of conductivity and structural stability, improves the electrochemical performance and cyclic stability of water-based zinc batteries, and reduces production costs.
Patent Information
- Application Number
- CN202510469157.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-15
- Publication Date
- 2025-07-04
AI Technical Summary
The existing layered double hydroxide (LDH) materials have shortcomings in electrical conductivity and structural stability during long cycles, which limits their application potential in the fields of supercapacitors, battery electrode materials and hydrogen storage.
The pretreatment of NiSA-SSA, the growth of ZIF-67 and the etching step of Ni are used to control the ratio of Ni and Co to form a highly controllable hierarchical structure, optimize the microstructure, and improve the uniformity and active sites of the material.
It improves the electrode conductivity and cyclic stability of NiCo-LDH material, enhances the electrochemical performance of aqueous zinc batteries, and reduces production costs.
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Figure CN120247122A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a preparation method and application of layered double hydroxides, belonging to the technical field of electrode materials. Background Art
[0002] Compared with traditional energy storage materials, layered double hydroxide (LDH) materials have adjustable metal composition and redox active sites, showing great application potential in the fields of supercapacitors, battery electrode materials, and hydrogen storage. However, LDH still faces some challenges in practical applications, especially the electrical conductivity and the structural stability of the material during long cycles need to be further optimized. Summary of the Invention
[0003] Aiming at the defects of the above-mentioned prior art, the present invention provides a preparation method of NiCo layered double hydroxide to improve the electrode conductivity and the cycle stability of the battery. The present invention also provides an application of NiCo layered double hydroxide in aqueous zinc batteries.
[0004] The technical solution of the present invention is as follows: A preparation method of NiCo layered double hydroxide, comprising the steps of:
[0005] Dissolve Ni(NO3)2·6H2O, 5-methylsalicylic acid, and thiosalicylic acid in DMF, and gradually add a NaOH solution. After stirring evenly, perform a hydrothermal reaction, and wash the reaction product to obtain a nickel-based salicyl complex;
[0006] Disperse the nickel-based salicyl complex in methanol containing PVP, centrifuge and collect, and redisperse in methanol to obtain a mixed solution;
[0007] Dissolve Co(NO3)2 in the mixed solution, add 2-methylimidazole, perform ultrasonic treatment and then aging, wash the product, and vacuum dry to obtain NiSA-SSA@ZIF-67;
[0008] Disperse NiSA-SSA@ZIF-67 in ethanol, add Ni(NO3)2 to etch NiSA-SSA@ZIF-67, then wash the product and vacuum dry to obtain NiCo layered double hydroxide.
[0009] Further, when Ni(NO3)2 etches NiSA-SSA@ZIF-67, the mass ratio of the added mass of Ni(NO3)2 to the mass of NiSA-SSA@ZIF-67 is (1-6):2, preferably 2.5:1.
[0010] Further, the molar ratio of Ni(NO3)2·6H2O, 5-methylsalicylic acid, and thiosalicylic acid is (1-2):(1-2.5):0.25.
[0011] Furthermore, the hydrothermal reaction temperature is 150 - 160 °C, and the reaction time is 3 - 5 h.
[0012] Furthermore, the ultrasonic frequency during ultrasonic treatment is 80 - 120 Hz.
[0013] Furthermore, when etching NiSA - SSA@ZIF - 67 by adding Ni(NO3)2 and then cleaning the product, ethanol is used for cleaning.
[0014] Furthermore, after stirring evenly, hydrothermal reaction is carried out, and then the reaction product is collected by centrifugation.
[0015] Another technical solution of the present invention is as follows: An application of NiCo layered double hydroxide in an aqueous zinc battery. The NiCo layered double hydroxide prepared by the preparation method of the NiCo layered double hydroxide is made into an electrode paste and coated on the surface of a titanium foil, and after drying, it is used as an electrode sheet of the aqueous zinc battery.
[0016] Furthermore, the NiCo layered double hydroxide made into an electrode paste includes an electrode material and a paste solvent. The electrode material includes 70% - 75% by mass of NiCo layered double hydroxide, 15% - 20% of conductive carbon black Super P, and the rest is a binder.
[0017] Compared with the prior art, the advantages of the technical solution provided by the present invention are as follows:
[0018] Through the pretreatment of NiSA - SSA, the growth of ZIF - 67, and the etching step of Ni, the present invention forms a highly controllable hierarchical structure, avoiding the problem of uneven morphology that may be caused by traditional methods. The ratio of Ni and Co is controlled by Ni(NO3)2 when etching NiSA - SSA@ZIF - 67 by adding Ni(NO3)2, realizing the optimization of the microstructure of layered double hydroxide (LDH). Compared with traditional LDH materials, it has a more uniform metal ion distribution and richer active sites, which helps to improve the cycle life and reduce the capacity attenuation problem caused by the collapse of the material structure.
[0019] The performance of NiCo - LDH in an aqueous zinc - ion battery is superior to that of LDH synthesized by the prior art (such as NiMn LDH nanosheets with a specific capacity of 106.3 mAh / g). At a current density of 5 mA / cm 2 ², the specific capacity is as high as 0.274 mAh / cm 2 ² (122 mAh / g). The material obtained by the method of the present invention has better charge storage capacity and cycle stability, making it more advantageous in aqueous energy storage applications.
[0020] The present invention uses a simple solvent method and a low-cost metal complex as a precursor, significantly reducing the production cost of the material and having good economic feasibility. Description of the Drawings
[0021] Figure 1 X-ray powder diffraction (XRD) pattern of NiCo layered double hydroxide in Example 1.
[0022] Figure 2 Fourier transform infrared (FT-IR) spectrum of NiCo layered double hydroxide in Example 1.
[0023] Figure 3 SEM image (magnification 5000 times) of NiCo layered double hydroxide in Example 1.
[0024] Figure 4 SEM image (magnification 10000 times) of NiCo layered double hydroxide in Example 1.
[0025] Figure 5 CV curve of the battery prepared with NiCo layered double hydroxide in Example 1 as the cathode material.
[0026] Figure 6 Cycling stability of the battery prepared with NiCo layered double hydroxide in Example 1 as the cathode material. Detailed Description of the Invention
[0027] The present invention will be further described below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. After reading this description, various equivalent modifications of this description by those skilled in the art fall within the scope defined by the appended claims of this application.
[0028] Example 1
[0029] Preparation method of NiCo layered double hydroxide, including the steps of:
[0030] (1) Dissolve 1 mmol of Ni(NO3)2·6H2O, 2.25 mmol of 5-methylsalicylic acid, and 0.25 mmol of thiosalicylic acid in 60 mL of DMF to form solution A.
[0031] (2) Dissolve 2.4 mmol of NaOH in 6 mL of deionized water to obtain solution B, and slowly add it dropwise to solution A and stir for 15 minutes.
[0032] (3) Transfer the mixed solution to a 100 mL autoclave, react at 160 °C for 3 hours, cool, then centrifuge, wash, and dry under vacuum to obtain nickel-based salicyl complex (NiSA-SSA-160).
[0033] (4) Disperse NiSA-SSA-160 in 15 mL of methanol containing 5% PVP (0.6111 g) and stir for 12 hours.
[0034] (5) Centrifuge to collect and redisperse in 20 mL of methanol to obtain the NiSA-SSAP mixed solution.
[0035] (6) Take 3 mL of the NiSA-SSAP mixed solution, add 20 mL of methanol, add 117.2 mg of Co(NO3)2 at room temperature, and ultrasonicate at 100 Hz for 5 minutes to obtain a homogeneous solution.
[0036] (7) Quickly add 20 mL of a methanol solution containing 259.6 mg of 2-methylimidazole and continue ultrasonication for 10 minutes.
[0037] (8) Age at room temperature for 6 hours, centrifuge to collect the product, and dry under vacuum at 60 °C for 12 hours to obtain NiSA-SSA@ZIF-67.
[0038] (9) Take 40 mg of NiSA-SSA@ZIF-67 and disperse it in 25 mL of ethanol.
[0039] (10) Add 100 mg of Ni(NO3)2 and carry out an etching reaction, with magnetic stirring for 1 hour.
[0040] (11) Wash 3 times by centrifugation with ethanol and finally dry under vacuum at 60 °C for 12 hours to obtain nickel-cobalt layered double hydroxide (denoted as NiCo-LDH-100).
[0041] Example 2
[0042] A method for preparing nickel-cobalt layered double hydroxide, where the mass of Ni(NO3)2 added in step (10) is 20 mg, and the other steps are the same as in Example 1, to obtain nickel-cobalt layered double hydroxide (denoted as NiCo-LDH-20).
[0043] Example 3
[0044] A method for preparing nickel-cobalt layered double hydroxide, where the mass of Ni(NO3)2 added in step (10) is 40 mg, and the other steps are the same as in Example 1, to obtain nickel-cobalt layered double hydroxide (denoted as NiCo-LDH-40).
[0045] Example 4
[0046] Preparation method of NiCo layered double hydroxide. In step (10), the mass of Ni(NO3)2 added is 60 mg, and the remaining steps are the same as those in Example 1, obtaining NiCo layered double hydroxide (denoted as NiCo-LDH-60).
[0047] Example 5
[0048] Preparation method of NiCo layered double hydroxide. In step (10), the mass of Ni(NO3)2 added is 80 mg, and the remaining steps are the same as those in Example 1, obtaining NiCo layered double hydroxide (denoted as NiCo-LDH-80).
[0049] Example 6
[0050] Preparation method of NiCo layered double hydroxide. In step (10), the mass of Ni(NO3)2 added is 120 mg, and the remaining steps are the same as those in Example 1, obtaining NiCo layered double hydroxide (denoted as NiCo-LDH-120).
[0051] The products prepared in Examples 1-6 were characterized by X-ray powder diffraction (XRD) test, and the obtained product diffraction patterns are as Figure 1 shown. The diffraction peaks at 11.6° (003) crystal plane, 34.6° (009) and 60.1° (110) positions indicate that NiCo-LDH was obtained in all examples.
[0052] In addition, the functional groups of NiCo-LDH prepared in Examples 1-6 were characterized by FT-IR test, and the results are as Figure 2 shown. The absorption peaks at 3500 cm -1 , 1630 cm -1 and 1380 cm -1 positions are attributed to ν(O-H), ν as (COO - ) and ν s (COO - ), further confirming that NiCo-LDH was obtained in Examples 1-6.
[0053] The morphology of NiCo-LDH prepared in Example 1 was characterized by SEM test, Figure 3 which is the scanning electron microscope photograph of NiCo-LDH prepared in Example 1. The test results show that the synthesized NiCo-LDH-100 prepared in Example 1 has an octahedral structure.
[0054] The morphology of NiCo-LDH prepared in Example 1 was characterized by TEM test, Figure 4Transmission electron microscope photograph of NiCo-LDH prepared in Example 1. The test results show that the synthesized NiCo-LDH-100 prepared in Example 1 has a hollow shell structure, proving the success of etching.
[0055] Example 7
[0056] Preparation method of NiCo layered double hydroxide, comprising the steps of:
[0057] (1) Dissolve 1.5 mmol of Ni(NO3)2·6H2O, 1.75 mmol of 5-methylsalicylic acid, and 0.25 mmol of thiosalicylic acid in 60 mL of DMF to prepare solution A.
[0058] (2) Dissolve 2.4 mmol of NaOH in 6 mL of deionized water to obtain solution B, and slowly add it dropwise to solution A, and stir for 15 minutes.
[0059] (3) Transfer the mixed solution to a 100 mL autoclave, react at 155 °C for 4 hours, cool, centrifuge and wash, and dry in vacuum to obtain nickel-based salicylate complex (NiSA-SSA-160).
[0060] (4) Disperse NiSA-SSA-160 in 15 mL of methanol containing 5% PVP (0.6111 g), and stir for 12 hours.
[0061] (5) Centrifuge and collect, and redisperse in 20 mL of methanol to obtain NiSA-SSAP mixed solution.
[0062] (6) Take 3 mL of NiSA-SSAP mixed solution, add 20 mL of methanol, add 117.2 mg of Co(NO3)2 at room temperature, and ultrasonicate at 80 Hz for 5 minutes until a homogeneous solution is obtained.
[0063] (7) Quickly add 20 mL of methanol solution containing 259.6 mg of 2-methylimidazole, and continue ultrasonication for 15 minutes.
[0064] (8) Age at room temperature for 6 hours, centrifuge and collect the product, and dry in vacuum at 60 °C for 12 hours to obtain NiSA-SSA@ZIF-67.
[0065] (9) Take 40 mg of NiSA-SSA@ZIF-67 and disperse it in 25 mL of ethanol.
[0066] (10) Add 100 mg of Ni(NO3)2, carry out an etching reaction, and stir magnetically for 1 hour.
[0067] (11) Wash 3 times by centrifugation with ethanol, and finally dry in vacuum at 60 °C for 12 hours to obtain NiCo layered double hydroxide.
[0068] Example 8
[0069] A preparation method of NiCo layered double hydroxide, comprising the steps of:
[0070] (1) Dissolve 2 mmol of Ni(NO3)2·6H2O, 1 mmol of 5-methylsalicylic acid and 0.25 mmol of thiosalicylic acid in 60 mL of DMF to form solution A.
[0071] (2) Dissolve 2.4 mmol of NaOH in 6 mL of deionized water to obtain solution B, and slowly add it dropwise to solution A, and stir for 15 minutes.
[0072] (3) Transfer the mixed solution to a 100 mL autoclave, react at 150 °C for 5 hours, cool, centrifuge, wash, and vacuum dry to obtain a nickel-based salicyl complex (NiSA-SSA-160).
[0073] (4) Disperse NiSA-SSA-160 in 15 mL of methanol containing 5% PVP (0.6111 g), and stir for 12 hours.
[0074] (5) Centrifuge and collect, and redisperse in 20 mL of methanol to obtain a NiSA-SSAP mixed solution.
[0075] (6) Take 3 mL of the NiSA-SSAP mixed solution, add 20 mL of methanol, add 117.2 mg of Co(NO3)2 at room temperature, and ultrasonicate at 120 Hz for 5 minutes to obtain a homogeneous solution.
[0076] (7) Quickly add 20 mL of a methanol solution containing 259.6 mg of 2-methylimidazole, and continue ultrasonication for 10 minutes.
[0077] (8) Age at room temperature for 6 hours, centrifuge and collect the product, and vacuum dry at 60 °C for 12 hours to obtain NiSA-SSA@ZIF-67.
[0078] (9) Take 40 mg of NiSA-SSA@ZIF-67 and disperse it in 25 mL of ethanol.
[0079] (10) Add 100 mg of Ni(NO3)2, carry out an etching reaction, and magnetically stir for 1 hour.
[0080] (11) Wash 3 times by centrifugation with ethanol, and finally vacuum dry at 60 °C for 12 hours to obtain NiCo layered double hydroxide.
[0081] Use the NiCo layered double hydroxide obtained in each example for battery assembly, and the steps are as follows:
[0082] (1) Weigh 0.5 g of polyvinylidene fluoride (PVDF) and add it to 9.5 g of N-methylpyrrolidone (NMP), and stir for 24 h to prepare PVDF with a mass fraction of 5%.
[0083] (2) Weigh 70 mg of NiCo layered double hydroxide and 20 mg of conductive carbon black Super P, and grind for 30 min.
[0084] (3) Weigh 200 mg of PVDF with a mass fraction of 5% and add it to step (2), and stir for 8 h to prepare the electrode slurry.
[0085] (4) Use a tetrahedral coating machine to evenly coat the electrode slurry prepared in step (3) on the surface of the titanium foil, and keep it in a vacuum drying oven at 60 °C for 12 h.
[0086] (5) Cut the electrode material prepared in step (4) into electrode sheets with a 12 mm mold.
[0087] (6) Prepare an electrolyte by configuring a mixed solution of 3 M KOH and 20 mM Zn(CH3COO)2.
[0088] (7) Use the electrode sheet in step (5) as the positive electrode, a zinc sheet as the negative electrode, select a glass fiber diaphragm, and a mixed solution of 3 M KOH and 20 mM Zn(CH3COO)2. Further electrochemical performance tests are carried out in a two-electrode system.
[0089] Perform GCD curve tests on the positive electrode materials prepared from NiCo-LDH of all examples, with a current density of 5 mA / cm 2 , to obtain the specific capacity of the electrode. The results of each example are as follows
[0090]
[0091] Figure 5 It is the GCD curve atlas of the battery prepared by using NiCo-LDH of Examples 1-6 as the positive electrode material.
[0092] Perform a cyclic stability test on the positive electrode material prepared in Example 1, with a current density of 3 mA / cm 2 , and the number of cycles is 500 to evaluate the performance of the battery. The cyclic stability atlas of the battery prepared by using NiCo-LDH-100 of Example 1 as the positive electrode material is as Figure 6 shown. It can be seen from the results that under the condition of etching with the addition of 100 mg of Ni(NO3)2, the obtained NiCo-LDH-100 has good morphological uniformity and the best electrochemical performance.
Claims
1. A preparation method of NiCo layered double hydroxide, characterized in that, Including the steps: Dissolve Ni(NO3)2·6H2O, 5-methylsalicylic acid and thiosalicylic acid in DMF, gradually add NaOH solution, stir evenly and then carry out hydrothermal reaction, and wash the reaction product to obtain nickel-based salicylate complex; Disperse the nickel-based salicylate complex in methanol containing PVP, centrifuge and collect, and redisperse in methanol to obtain a mixed solution; Dissolve Co(NO3)2 in the mixed solution, add 2-methylimidazole, carry out ultrasonic treatment and then aging, wash the product, and vacuum dry to obtain NiSA-SSA@ZIF-67; Disperse NiSA-SSA@ZIF-67 in ethanol, add Ni(NO3)2 to etch NiSA-SSA@ZIF-67, then wash the product and vacuum dry to obtain NiCo layered double hydroxide.
2. The preparation method of the NiCo layered double hydroxide according to claim 1, characterized in that, When Ni(NO3)2 is used to etch NiSA-SSA@ZIF-67, the mass ratio of the added mass of Ni(NO3)2 to the mass of NiSA-SSA@ZIF-67 is (1-6):
2.
3. The preparation method of the NiCo layered double hydroxide according to claim 1, characterized in that, When Ni(NO3)2 is used to etch NiSA-SSA@ZIF-67, the mass ratio of the added mass of Ni(NO3)2 to the mass of NiSA-SSA@ZIF-67 is 2.5:
1.
4. The preparation method of the NiCo layered double hydroxide according to claim 1, wherein The molar ratio of Ni(NO3)2·6H2O, 5-methylsalicylic acid and thiosalicylic acid is (1-2):(1-2.5):0.
25.
5. The preparation method of the NiCo layered double hydroxide according to claim 1, wherein, The hydrothermal reaction temperature is 150-160 °C, and the reaction time is 3-5 h.
6. The preparation method of the NiCo layered double hydroxide according to claim 1, wherein, The ultrasonic frequency during the ultrasonic treatment is 80-120 Hz.
7. The preparation method of the NiCo layered double hydroxide according to claim 1, wherein, When adding Ni(NO3)2 to etch NiSA-SSA@ZIF-67 and then washing the product, ethanol is used for washing.
8. The preparation method of the NiCo layered double hydroxide according to claim 1, characterized in that, After stirring evenly and carrying out hydrothermal reaction, centrifuge to collect the reaction product.
9. Application of NiCo layered double hydroxide in aqueous zinc batteries, characterized in that, Make the NiCo layered double hydroxide prepared by the preparation method of the NiCo layered double hydroxide according to any one of claims 1 to 8 into an electrode paste, coat it on the surface of a titanium foil, and dry it to obtain an electrode sheet for an aqueous battery.
10. The application of the NiCo layered double hydroxide according to claim 9 in an aqueous zinc battery, characterized in that, The NiCo layered double hydroxide made into an electrode paste includes an electrode material and a paste solvent. The electrode material includes 70%-75% of NiCo layered double hydroxide, 15%-20% of conductive carbon black Super P by mass, and the rest is a binder.