Preparation method of NiSH nano material and application of NiSH nano material in aqueous nickel-zinc battery

Abstract

The invention discloses a preparation method of a NiSH nano material, which comprises the following steps: dissolving nickel salt in absolute ethyl alcohol to form a solution A, and dissolving an organic ligand thiosalicylic acid in absolute ethyl alcohol to form an organic ligand solution B; mixing the solution A and the organic ligand solution B, and performing stirring reaction to obtain a mixed solution C; the mixed solution C and deionized water are mixed and stirred, guest molecules are added, stirring continues to be conducted, heating reaction is conducted, after the reaction is finished, products are collected and cleaned through centrifugation, the products are dried away from light, and the NiSH nanometer material is obtained, and the guest molecules are 4-fluorosalicylic acid, 4-trifluoromethylsalicylic acid or 4-bromosalicylic acid. According to the application of the NiSH nanometer material in the water-based nickel-zinc battery, the NiSH nanometer material is prepared into electrode slurry, the surface of carbon cloth is coated with the electrode slurry, and the electrode slurry is used as an electrode plate of the water-based nickel-zinc battery after being dried. The NiSH nano material prepared by the method has high conductivity and cycling stability, and the electrochemical performance of the aqueous nickel-zinc battery can be improved.

Description

Technical Field

[0001] The present invention relates to a preparation method and application of NiSH, belonging to the technical field of electrode materials. Background Art

[0002] Nickel-zinc batteries (NZBs) have a high working voltage platform and ultra-high power density. However, there is a significant gap between the specific capacity of the nickel-based cathode and the theoretical value, which is mainly due to the inherent crystal structure rigidification of traditional inorganic nickel oxides and the problem of sluggish multi-electron transfer kinetics.

[0003] Metal-organic framework materials with a designable coordination microenvironment can break through the performance constraints of inorganic materials. The three-dimensional conductive framework constructed by such materials through π-π stacking interactions and directional hydrogen bond networks can not only provide multi-level ion transport channels, but also the dynamic coordination bond reconstruction characteristics can achieve self-adaptive volume regulation of the electrode material during charge and discharge. Especially for the nickel-based coordination system introduced with chalcogen heteroatoms, experiments have confirmed that nickel thiosalicylate complexes exhibit a two-electron cooperative storage mechanism when used as the positive electrode material. However, this system still has the problem of progressive distortion of the coordination structure during deep deintercalation, resulting in poor cycle stability of the battery. Summary of the Invention

[0004] Aiming at the defects of the above-mentioned prior art, the present invention provides a preparation method of NiSH nanomaterials with the aim of improving the cycle stability of the battery. The present invention also provides an application of NiSH nanomaterials in aqueous nickel-zinc batteries.

[0005] The technical solution of the present invention is as follows: A preparation method of NiSH nanomaterials, comprising the steps of:

[0006] Dissolve nickel salt in absolute ethanol to form solution A, and dissolve the organic ligand thiosalicylic acid in absolute ethanol to form organic ligand solution B;

[0007] Mix the solution A and the organic ligand solution B and then carry out a stirring reaction to obtain a mixed solution C;

[0008] Mix the mixed solution C with deionized water, stir, add a guest molecule, continue to stir and heat the reaction, and after completion, collect the washed product by centrifugation and dry it in the dark to obtain NiSH nanomaterials, and the guest molecule is 4-fluorosalicic acid, 4-trifluoromethylsalicylic acid or 4-bromosalicylic acid.

[0009] Further, after mixing the mixed solution C with deionized water, adjust the pH value of the solution to change the particle size of the prepared NiSH nanomaterials.

[0010] Further, the adjustment range of the pH value is 2-12.

[0011] Further, the molar ratio of the nickel salt, the organic ligand thiosalicylic acid, and the guest molecule is (4-10):(4-10):1.

[0012] Further, the temperature during the heating reaction is 110-120 °C.

[0013] Further, the nickel salt is Ni(CH3COO)2·4H2O.

[0014] Further, the stirring speed during the stirring reaction is not less than 400 r / min, and the stirring reaction time is 10-40 min.

[0015] Further, the light-shielding drying is carried out at room temperature, and the light-shielding drying time is 8-24 h.

[0016] Another technical solution of the present invention is as follows: An application of a NiSH nanomaterial in an aqueous nickel-zinc battery. The NiSH nanomaterial prepared by the preparation method of the NiSH nanomaterial is made into an electrode paste and coated on the surface of carbon cloth, and after drying, it is used as an electrode sheet of the aqueous nickel-zinc battery.

[0017] Further, the NiSH nanomaterial made into the electrode paste includes an electrode material and a paste solvent. The electrode material includes 40%-50% of the NiSH nanomaterial and 40%-50% of acetylene black by mass, and the rest is a binder.

[0018] Compared with the prior art, the advantages of the technical solution provided by the present invention are as follows:

[0019] The present invention uses thiosalicylic acid as an organic ligand, introduces a guest molecule for compounding, adjusts the crystal structure of NiSH, improves the structural characteristics of the material during the synthesis process, has a larger specific surface area, better ion transport channels and higher stability, which helps to improve the electrochemical properties of NiSH. Further combined with the control of the reaction pH value, NiSH of different sizes can be synthesized and controlled.

[0020] The in-situ composite NiSH has better performance in the aqueous nickel-zinc battery than the NiSH synthesized by the prior art, has better conductivity, charge storage capacity and cycle stability, making it more advantageous in applications such as energy storage and electrocatalysis.

[0021] The present invention has simple operation, easy reaction control, good repeatability, good safety, and is suitable for continuous large-scale production. Description of the Drawings

[0022] Figure 1 It is the SEM pattern of the NiSH nanomaterial prepared in Example 1.

[0023] Figure 2XRD patterns of the NiSH nanomaterials prepared in Examples 1, 2, and 3.

[0024] Figure 3 FT-IR spectra of the NiSH nanomaterials prepared in Examples 1, 2, and 3.

[0025] Figure 4 SEM images of NiSH prepared in Example 4-9 at different pH values.

[0026] Figure 5 CV curve spectra of the battery prepared with the NiSH nanomaterial of Example 1 as the cathode material.

[0027] Figure 6 Cycling stability spectra of the battery prepared with the NiSH nanomaterial of Example 1 as the cathode material. Detailed implementation mode

[0028] The present invention will be further described below in conjunction with the 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 forms of modification of this description by those skilled in the art all fall within the scope defined by the appended claims of this application.

[0029] Example 1

[0030] A preparation method of NiSH nanomaterials, including the steps:

[0031] Weigh 1 mmol of nickel acetate tetrahydrate Ni(CH3COO)2·4H2O and put it into a solution of 5 mL of absolute ethanol, and obtain a green solution A through a magnetic stirrer; weigh 2.25 mmol of thiosalicylic acid in 5 mL of absolute ethanol solution to form an organic ligand solution B.

[0032] While stirring, add the organic ligand solution B to the solution A, and stir and react for 10 min at a rotation speed of 550 r / min through a magnetic stirrer to obtain a mixed solution C.

[0033] Mix the mixed solution C with 1 mL of deionized water and stir for 15 min to obtain a mixed solution D.

[0034] Mix the mixed solution D with 0.25 mmol of the guest molecule 4-fluorosalicylate, transfer it to a polytetrafluoroethylene stainless steel reaction kettle, heat it in an oven to 120 °C and react for 3 h. After washing the obtained precipitate with absolute ethanol, dry it in the dark at room temperature for 12 h to obtain the NiSH nanomaterial NiSH@Ni-FSA.

[0035] Characterize the morphology of the NiSH nanomaterial NiSH@Ni-FSA prepared in Example 1 by SEM test, asFigure 1 As shown, the synthesized NiSH nanomaterial NiSH@Ni-FSA is basically uniform in size and shape.

[0036] Example 2

[0037] A method for preparing a NiSH nanomaterial, using the guest molecule 4-trifluoromethylsalicylic acid instead of 4-fluorosalicylic acid, and the remaining steps are the same as in Example 1, to obtain the NiSH nanomaterial NiSH@Ni-CF3SA.

[0038] Example 3

[0039] A method for preparing a NiSH nanomaterial uses the guest molecule 4-bromosalicylic acid instead of 4-fluorosalicylic acid, and the remaining steps are the same as in Example 1, to obtain the NiSH nanomaterial NiSH@Ni-BrSA.

[0040] The NiSH nanomaterials prepared in Examples 1, 2, and 3 were characterized by X-ray powder diffraction (XRD) test, and the obtained diffraction patterns are as Figure 2 shown, indicating that NiSH nanomaterials can also be prepared by changing the guest molecule.

[0041] In addition, the functional groups of the NiSH nanomaterials prepared in Examples 1, 2, and 3 were characterized by FT-IR test, and the results are as Figure 3 shown, and the absorption peak at the position of 1033 cm -1 is attributed to δ(C-S), further confirming that the NiSH nanomaterials were prepared in Examples 1, 2, and 3.

[0042] Example 4

[0043] A method for preparing a NiSH nanomaterial includes the steps of:

[0044] Weigh 1 mmol of nickel acetate tetrahydrate Ni(CH3COO)2·4H2O and put it into a solution of 5 mL of absolute ethanol, and obtain a green solution A by a magnetic stirrer; weigh 2.25 mmol of thiosalicylic acid in 5 mL of absolute ethanol solution to form an organic ligand solution B.

[0045] While stirring, add the organic ligand solution B to the solution A, and stir and react for 10 min at a rotation speed of 550 r / min by a magnetic stirrer to obtain a mixed solution C.

[0046] Mix the mixed solution C with 1 mL of deionized water, add HCl to adjust the pH value to 2.3, and stir for 15 min to obtain a mixed solution D.

[0047] Mix the mixed solution D with 0.25 mmol of the guest molecule 4-fluorosalicylic acid, transfer it to a polytetrafluoroethylene stainless steel autoclave, and heat it in an oven at 120 °C for 3 h. After washing the precipitate obtained from the reaction with absolute ethanol, dry it in the dark at room temperature for 12 h to obtain the NiSH nanomaterial NiSH@Ni-FSA.

[0048] Example 5

[0049] A method for preparing a NiSH nanomaterial. After mixing the mixed solution C with 1 mL of deionized water, add HCl to adjust the pH value to 3.3, and the remaining steps are the same as those in Example 4 to obtain the NiSH nanomaterial NiSH@Ni-FSA.

[0050] Example 6

[0051] A method for preparing a NiSH nanomaterial. After mixing the mixed solution C with 1 mL of deionized water, add HCl to adjust the pH value to 4.3, and the remaining steps are the same as those in Example 4 to obtain the NiSH nanomaterial NiSH@Ni-FSA.

[0052] Example 7

[0053] A method for preparing a NiSH nanomaterial. After mixing the mixed solution C with 1 mL of deionized water, add NaOH to adjust the pH value to 10, and the remaining steps are the same as those in Example 4 to obtain the NiSH nanomaterial NiSH@Ni-FSA.

[0054] Example 8

[0055] A method for preparing a NiSH nanomaterial. After mixing the mixed solution C with 1 mL of deionized water, add NaOH to adjust the pH value to 10, and the remaining steps are the same as those in Example 4 to obtain the NiSH nanomaterial NiSH@Ni-FSA.

[0056] Example 9

[0057] A method for preparing a NiSH nanomaterial. After mixing the mixed solution C with 1 mL of deionized water, add NaOH to adjust the pH value to 10, and the remaining steps are the same as those in Example 4 to obtain the NiSH nanomaterial NiSH@Ni-FSA.

[0058] Characterize the morphology of the NiSH nanomaterial NiSH@Ni-FSA prepared in Examples 4-9 by SEM testing. As Figure 4 shown, it can be seen that by adjusting different pH values, NiSH nanomaterials with different particle sizes can be obtained.

[0059] Example 10

[0060] A method for preparing a NiSH nanomaterial, including the steps:

[0061] Weigh 2.5 mmol of nickel(II) acetate tetrahydrate Ni(CH3COO)2·4H2O and put it into a 5 mL solution of absolute ethanol, and obtain a green solution A through a magnetic stirrer; weigh 1 mmol of thiosalicylic acid in a 5 mL absolute ethanol solution to form an organic ligand solution B.

[0062] While stirring, add the organic ligand solution B to solution A, and stir and react for 10 min at a rotation speed of 550 r / min through a magnetic stirrer to obtain a mixed solution C.

[0063] Mix the mixed solution C with 1 mL of deionized water and stir for 20 min to obtain a mixed solution D.

[0064] Mix the mixed solution D with 0.25 mmol of the guest molecule 4-fluorosalicylate, transfer it to a polytetrafluoroethylene stainless steel autoclave, heat it in an oven to 120 °C and react for 3 h. After washing the obtained precipitate with absolute ethanol, dry it in the dark at room temperature for 8 h to obtain the NiSH nanomaterial NiSH@Ni-FSA.

[0065] Example 11

[0066] A preparation method of a NiSH nanomaterial, comprising the steps:

[0067] Weigh 1.5 mmol of nickel(II) acetate tetrahydrate Ni(CH3COO)2·4H2O and put it into a 5 mL solution of absolute ethanol, and obtain a green solution A through a magnetic stirrer; weigh 1.5 mmol of thiosalicylic acid in a 5 mL absolute ethanol solution to form an organic ligand solution B.

[0068] While stirring, add the organic ligand solution B to solution A, and stir and react for 10 min at a rotation speed of 550 r / min through a magnetic stirrer to obtain a mixed solution C.

[0069] Mix the mixed solution C with 1 mL of deionized water and stir for 40 min to obtain a mixed solution D.

[0070] Mix the mixed solution D with 0.25 mmol of the guest molecule 4-fluorosalicylate, transfer it to a polytetrafluoroethylene stainless steel autoclave, heat it in an oven to 120 °C and react for 3 h. After washing the obtained precipitate with absolute ethanol, dry it in the dark at room temperature for 24 h to obtain the NiSH nanomaterial NiSH@Ni-FSA.

[0071] Example 12

[0072] A preparation method of NiSH nanomaterial. After mixing mixed solution D with guest molecules, it is transferred to a polytetrafluoroethylene stainless steel reaction kettle, heated in an oven to 100 °C for reaction, and the remaining steps are the same as those in Example 1, to obtain the NiSH nanomaterial NiSH@Ni-FSA.

[0073] Example 13

[0074] A preparation method of NiSH nanomaterial. After mixing mixed solution D with guest molecules, it is transferred to a polytetrafluoroethylene stainless steel reaction kettle, heated in an oven to 110 °C for reaction, and the remaining steps are the same as those in Example 1, to obtain the NiSH nanomaterial NiSH@Ni-FSA.

[0075] Example 14

[0076] A preparation method of NiSH nanomaterial. After mixing mixed solution D with guest molecules, it is transferred to a polytetrafluoroethylene stainless steel reaction kettle, heated in an oven to 130 °C for reaction, and the remaining steps are the same as those in Example 1, to obtain the NiSH nanomaterial NiSH@Ni-FSA.

[0077] Comparative example

[0078] A preparation method of NiSH nanomaterial, including the steps:

[0079] Weigh 1 mmol of nickel acetate tetrahydrate Ni(CH3COO)2·4H2O and put it into a solution of 5 mL of absolute ethanol, and obtain a green solution A through a magnetic stirrer; weigh 2.25 mmol of thiosalicylic acid in a 5 mL absolute ethanol solution to form an organic ligand solution B.

[0080] While stirring, add the organic ligand solution B to solution A, and stir and react for 10 min at a rotation speed of 550 r / min through a magnetic stirrer to obtain a mixed solution C.

[0081] Mix the mixed solution C with 1 mL of deionized water, stir for 15 min to obtain a mixed solution D. Transfer it to a polytetrafluoroethylene stainless steel reaction kettle, heat it in an oven to 120 °C for reaction for 3 h. The precipitate obtained from the reaction is washed with absolute ethanol and dried in the dark to obtain the NiSH nanomaterial

[0082] Use the NiSH nanomaterials obtained in Example 1, Examples 4 - 14 and the comparative example to assemble batteries, and the steps are as follows:

[0083] (1) Weigh 0.5 g of PVDF and add 9.5 g of NMP, stir for 24 h to prepare PVDF with a mass fraction of 5%.

[0084] (2) Weigh 25 mg of NiSH nanomaterial and 25 mg of acetylene carbon and grind for 30 min.

[0085] (3) Weigh 200 mg of PVDF with a mass fraction of 5%, add it to step (2), and stir for 8 h to prepare the electrode slurry.

[0086] (4) Use a tetrahedral coating machine to uniformly coat the electrode slurry prepared in step (3) on the carbon cloth and carbon surface, and keep it in a vacuum drying oven at 60 °C for 24 h to obtain the electrode sheet.

[0087] (5) Prepare a 20 mM Zn(AC)2 electrolyte solution.

[0088] (6) Use the electrode sheet from step (4) as the positive electrode, a zinc sheet as the negative electrode, select a glass fiber diaphragm as the separator, and 20 mM Zn(AC)2 as the electrolyte. Assemble a button battery by a traditional method. The positive and negative electrodes are made of a CR2032 type stainless steel shell. After the assembled battery is left standing for 24 h, further electrochemical performance tests are carried out.

[0089] Perform a CV curve test on the assembled battery to obtain the redox potential of the electrode and analyze the electrochemical reactions occurring at specific potentials. Figure 5 It is the CV curve pattern of the battery prepared with the NiSH nanomaterial obtained in Example 1 as the positive electrode material.

[0090] Perform a cyclic stability test on the assembled battery, with a current density of 5 mA cm -2 , and the number of cycles is 500 to evaluate the performance of the battery. The cyclic stability patterns of the batteries prepared with the NiSH nanomaterials obtained in Example 1 and the comparative example as the positive electrode materials are as Figure 6 shown. Among them, the NiSH nanomaterial in Example 1 is NiSH@Ni-FSA, and the NiSH nanomaterial in the comparative example is NiSH. It can be seen that the Coulomb efficiency remains stable. Although the specific capacity after 500 cycles is comparable to that of the NiSH material obtained in the comparative example, the attenuation rate in the first 400 cycles is less than that of the comparative example, indicating that it has better cyclic stability. After testing, the NiSH nanomaterials obtained in the remaining Examples 4 - 14 also have cyclic stability similar to that of Example 1.

Claims

1. A method for preparing NiSH nanomaterials, characterized in that, Including the steps: Dissolve nickel salt in absolute ethanol to form solution A, and dissolve organic ligand thiosalicylic acid in absolute ethanol to form organic ligand solution B; Mix the solution A and the organic ligand solution B and carry out a stirring reaction to obtain a mixed solution C; Mix the mixed solution C with deionized water, stir, add guest molecules, continue to stir and heat for reaction. After completion, collect the washed product by centrifugation and dry it in the dark to obtain NiSH nanomaterials. The guest molecules are 4-fluorosalicylate, 4-trifluoromethylsalicylate or 4-bromosalicylate.

2. The preparation method of the NiSH nanomaterial according to claim 1, characterized in that, Mix the mixed solution C with deionized water and then adjust the pH value of the solution to change the particle size of the prepared NiSH nanomaterials.

3. The preparation method of the NiSH nanomaterial according to claim 2, characterized in that, The adjusted range of the pH value is 2-12.

4. The preparation method of the NiSH nanomaterial according to any one of claims 1 to 3, characterized in that, The molar ratio of the nickel salt, the organic ligand thiosalicylic acid and the guest molecule is (4-10):(4-10):

1.

5. The preparation method of the NiSH nanomaterial according to claim 1, characterized in that, The temperature during the heating reaction is 110-120 °C, and the heating reaction time is 3-12 h.

6. The preparation method of the NiSH nanomaterial according to claim 1, characterized in that, The nickel salt is Ni(CH3COO)2·4H2O.

7. The preparation method of the NiSH nanomaterial according to claim 1, wherein The stirring speed during the stirring reaction is not less than 400 r / min, and the stirring reaction time is 10-40 min.

8. The preparation method of the NiSH nanomaterial according to claim 1, characterized in that, The drying in the dark is carried out at room temperature, and the drying time in the dark is 8-24 h.

9. Application of NiSH nanomaterial in aqueous nickel-zinc battery, characterized in that, Make the NiSH nanomaterials prepared by the preparation method of the NiSH nanomaterials according to any one of claims 1 to 8 into an electrode paste, coat it on the surface of carbon cloth, and dry it to obtain an electrode sheet for an aqueous nickel-zinc battery.

10. The application of the NiSH nanomaterial according to claim 9 in an aqueous nickel-zinc battery, characterized in that, The electrode paste made of the NiSH nanomaterials includes an electrode material and a paste solvent. The electrode material includes 40%-50% of NiSH nanomaterials, 40%-50% of acetylene black by mass, and the rest is a binder.

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