Aqueous zinc ion battery electrode material, preparation and application thereof

Abstract

The present application relates to an aqueous zinc ion battery electrode material, a preparation method and its application. The electrode material is Ce-doped NiMn2O4, which presents a porous hollow spherical structure with a diameter range of 1.5μm-3.5μm. The preparation method comprises: dissolving Ni salt and Mn salt in ethylene glycol to obtain a NiMn2O4 precursor solution; dissolving Ce salt in ethylene glycol to obtain a doped Ce salt solution; uniformly mixing the NiMn2O4 precursor solution and the Ce salt solution, transferring the mixture to a reactor, placing the mixture in a microwave reactor for reaction, and calcining the mixture at 300-400°C after the reaction to generate oxygen vacancies in the NiMn2O4 lattice by Ce doping, thereby improving conductivity; the special porous hollow structure effectively increases the contact specific surface area between the material and the electrolyte, thereby providing more active sites for the storage of zinc ions.

Description

Technical Field

[0001] The invention relates to an aqueous zinc ion battery positive electrode material and a preparation method and application thereof, belonging to the technical field of zinc ion batteries. Background Art

[0002] Compared to lithium-ion batteries (LIBs), aqueous zinc-ion batteries (AZIBs) have the advantages of safety, environmental friendliness, high conductivity, high specific capacity, and excellent rate performance, and have attracted widespread attention in the field of new energy storage. Currently, the cathode materials for aqueous zinc-ion batteries mainly include manganese-based materials, vanadium-based materials, and Prussian blue, and the variety is relatively limited. Therefore, the design and development of cathode materials with high capacity, high rate, and high cycle performance is a top priority for achieving high-quality development of zinc-ion batteries.

[0003] Chinese patent document CN117525329A discloses a NiMn2O4 / Mn3O4 / Mn2O3 ternary composite electrode material, which is used as a positive electrode material for aqueous zinc ion batteries. The specific preparation method is to mix manganese chloride tetrahydrate and sucrose, and completely dissolve the mixture with deionized water, introduce an appropriate amount of nickel chloride hexahydrate into the obtained mixed solution and dissolve it, transfer the obtained mixed solution into a porcelain boat, place it in a muffle furnace, heat it to 600°C and keep it warm for 3 hours. The material preparation process involved in this patent is simple and efficient, but the material agglomeration phenomenon is serious, and the rate performance and cycle performance are poor; Chinese patent document CN117457883A discloses a two-dimensional layered van der Waals heterostructure Bi2Te3 / MnBi2Te4 positive electrode applied to aqueous zinc ion batteries, at 0.2Ag -1 At a current density of 349 mAh g -1 High reversible capacity and excellent cycling stability at 2Ag -1 At a current density of , the capacity retention rate reaches 77% after 3500 charge and discharge cycles. There is a strong interfacial interaction between the different two phases, which realizes the fast ion diffusion kinetics and high cycle stability of the rechargeable aqueous zinc ion battery positive electrode. However, the material composition is complex and the cost is high; Chinese patent document CN117393707A discloses a MnCO3 / Mn3O4 heterostructure material and its preparation method and application. MnCO3 / Mn3O4 heterostructure material is prepared by a one-step solvent thermal method using manganese acetate and urea as raw materials. MnCO3 and Mn3O4, two materials with similar crystal structures, are compounded. Nanospheres of MnCO3 and Mn3O4 form nanosheets, which are then stacked on each other. Nanosheets close to the "core" position are squeezed to form a bow-tie-like structure. The nanosheet layers in the structure expose more active sites, which is conducive to the insertion / extraction of zinc ions between the layers. The material has good dispersibility. However, the discharge specific capacity is low and cannot meet actual commercial needs. Summary of the Invention

[0004] In view of the above problems, the object of the present invention is to provide an aqueous zinc ion battery electrode material having high capacity, high rate performance and high cycle performance and a preparation method thereof.

[0005] An aqueous zinc ion battery electrode material, the electrode material is Ce-doped NiMn2O4, which presents a porous hollow spherical structure with a diameter ranging from 1.5 μm to 3.5 μm. The preparation method comprises the following steps:

[0006] Step 1: Dissolve Ni salt and Mn salt in ethylene glycol and stir magnetically to prepare a NiMn2O4 precursor solution;

[0007] Step 2: Dissolve the Ce salt in ethylene glycol and mix evenly with magnetic stirring to obtain a Ce salt doped solution;

[0008] Step 3: Mix the NiMn2O4 precursor solution and the Ce salt solution, disperse and mix them evenly by ultrasonic dispersion, transfer them to a reactor, place them in a microwave reactor, set the reaction temperature to 160-180°C, the reaction time to 1-5h, and the power to 400-800W. After the reaction is completed, cool, centrifuge, filter, wash, and dry to obtain the product;

[0009] Step 4: calcining the product obtained in step 3 in a tube furnace at 300-400° C. for 1-2 h.

[0010] Wherein, in step 1, the Ni salt is selected from one or more of nickel chloride, nickel sulfate, and nickel nitrate;

[0011] Wherein, in step 1, the Mn salt is selected from one or more of manganese chloride, manganese sulfate, and manganese nitrate;

[0012] Wherein, in step 2, the Ce salt is selected from one or more of cerium chloride, cerium sulfate, and cerium nitrate;

[0013] The magnetic stirring time in steps 1 and 2 is set to 10-20 min;

[0014] Wherein, the molar ratio of the three metal salts of Ce salt, Ni salt and Mn salt is (0.02-0.1):1:2;

[0015] Compared with the prior art, this application achieves the following beneficial technical effects:

[0016] This application uses a microwave-solvothermal method to introduce Ce element doping into the NiMn2O4 precursor solution to prepare a porous hollow spherical Ce-doped NiMn2O4 electrode material. Ce is incorporated into the NiMn2O4 lattice to generate oxygen vacancies, thereby improving conductivity; the special porous hollow structure effectively increases the contact specific surface area between the material and the electrolyte, thereby providing more active sites for the storage of zinc ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a scanning electron microscope image of Ce-doped NiMn2O4 prepared in Example 1;

[0018] Figure 2 This is a scanning electron microscope image of the aqueous zinc ion battery electrode material prepared in Comparative Example 1;

[0019] Figure 3 This is a scanning electron microscope image of the aqueous zinc ion battery electrode material prepared in Comparative Example 2;

[0020] Figure 4 Electrochemical rate performance diagram of the materials prepared in Example 1 and Comparative Examples 1-2 as positive electrode materials for aqueous zinc ion batteries;

[0021] Figure 5 Electrochemical cycle performance diagram of the materials prepared in Example 1 and Comparative Examples 1-2 as positive electrode materials for aqueous zinc ion batteries. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0023] Example 1

[0024] Step 1: Dissolve nickel nitrate and manganese chloride in 45 mL of ethylene glycol at a molar ratio of 1:2, wherein nickel nitrate is 0.1 mol and manganese chloride is 0.2 mol, and stir magnetically for 20 minutes to prepare a NiMn2O4 precursor solution;

[0025] Step 2: Dissolve 0.005 mol cerium nitrate in 20 mL ethylene glycol and stir magnetically for 20 min to mix evenly to obtain a doped cerium nitrate solution;

[0026] Step 3: Mix the NiMn2O4 precursor solution and the cerium nitrate solution, disperse and mix them evenly by ultrasonic dispersion, transfer them into a reactor, place them in a microwave reactor, set the reaction temperature to 180°C, the reaction time to 2 hours, and the power to 600W. After the reaction is completed, cool, centrifuge, filter, wash, and dry to obtain the product;

[0027] Step 4: The product obtained in step 3 was calcined in a tube furnace at 300° C. for 1 h.

[0028] Example 2

[0029] Step 1: Dissolve nickel nitrate and manganese chloride in 45 mL of ethylene glycol at a molar ratio of 1:2, wherein nickel nitrate is 0.1 mol and manganese chloride is 0.2 mol, and stir magnetically for 20 minutes to prepare a NiMn2O4 precursor solution;

[0030] Step 2: Dissolve 0.01 mol cerium nitrate in 20 mL ethylene glycol and mix thoroughly under magnetic stirring for 20 min to obtain a doped cerium nitrate solution;

[0031] Step 3: Mix the NiMn2O4 precursor solution and the cerium nitrate solution, disperse and mix them evenly by ultrasonic dispersion, transfer them into a reactor, place them in a microwave reactor, set the reaction temperature to 180°C, the reaction time to 2 hours, and the power to 600W. After the reaction is completed, cool, centrifuge, filter, wash, and dry to obtain the product;

[0032] Step 4: The product obtained in step 3 was calcined in a tube furnace at 300° C. for 1 h.

[0033] Example 3

[0034] Step 1: Dissolve nickel nitrate and manganese chloride in 45 mL of ethylene glycol at a molar ratio of 1:2, wherein nickel nitrate is 0.15 mol and manganese chloride is 0.3 mol, and stir magnetically for 20 minutes to prepare a NiMn2O4 precursor solution;

[0035] Step 2: Dissolve 0.0075 mol cerium nitrate in 20 mL ethylene glycol and mix thoroughly under magnetic stirring for 20 min to obtain a doped cerium nitrate solution;

[0036] Step 3: Mix the NiMn2O4 precursor solution and the cerium nitrate solution, disperse and mix them evenly by ultrasonic dispersion, transfer them into a reactor, place them in a microwave reactor, set the reaction temperature to 180°C, the reaction time to 3 hours, and the power to 600W. After the reaction is completed, cool, centrifuge, filter, wash, and dry to obtain the product;

[0037] Step 4: The product obtained in step 3 was calcined in a tube furnace at 300° C. for 1 h.

[0038] Comparative Example 1-No Ce doping

[0039] Step 1: Dissolve nickel nitrate and manganese chloride in 45 mL of ethylene glycol at a molar ratio of 1:2, wherein nickel nitrate is 0.1 mol and manganese chloride is 0.2 mol, and stir magnetically for 20 minutes to prepare a NiMn2O4 precursor solution;

[0040] Step 2: Transfer the NiMn2O4 precursor solution into a reaction kettle, place it in a microwave reactor, set the reaction temperature to 180°C, the reaction time to 2 hours, and the power to 600W. After the reaction is completed, cool, centrifuge, filter, wash, and dry to obtain the product;

[0041] Step 3: The product obtained in step 3 was calcined in a tube furnace at 300° C. for 1 h.

[0042] Comparative Example 2 - No microwave solvent thermal method

[0043] Step 1: Dissolve nickel nitrate and manganese chloride in 45 mL of ethylene glycol at a molar ratio of 1:2, wherein nickel nitrate is 0.1 mol and manganese chloride is 0.2 mol, and stir magnetically for 20 minutes to prepare a NiMn2O4 precursor solution;

[0044] Step 2: Dissolve 0.005 mol cerium nitrate in 20 mL ethylene glycol and stir magnetically for 20 min to mix evenly to obtain a doped cerium nitrate solution;

[0045] Step 3: Mix the NiMn2O4 precursor solution and the cerium nitrate solution, disperse and mix them evenly by ultrasonic dispersion, transfer them to a reactor, use conventional solvent heat, set the reaction temperature to 180°C, the reaction time to 2 hours, and the power to 600W, cool after the reaction, centrifuge, filter, wash, and dry to obtain the product;

[0046] Step 4: The product obtained in step 3 was calcined in a tube furnace at 300° C. for 1 h.

[0047] Battery Assembly:

[0048] The positive electrode materials prepared in Example 1 and Comparative Examples 1-2 were respectively mixed with carbon black and PVDF in a mass ratio of 8:1:1, and NMP was added and stirred to obtain an electrode slurry. The prepared slurry was coated on the surface of the current collector and vacuum dried. The cut pieces were used as the positive electrode of the aqueous zinc ion battery; the zinc sheet was used as the negative electrode, and the glass fiber was used as the separator; the electrolyte was a mixed solution of 2 mol / L ZnSO4 and 0.5 mol / L MnSO4 as the electrolyte solution, and an aqueous zinc ion battery was assembled.

[0049] Through the SEM image analysis of Example 1, it can be seen that the final morphology of the product is a porous hollow spherical structure with a diameter range of 1.5μm-3.5μm; using the method of Comparative Example 1, the final material is a block structure with a concave and convex surface, while Comparative Example 2 forms a hollow structure; therefore, the introduction of Ce and microwave solvent heat directly affect the structure of the material. If any one of these factors is eliminated, it is difficult to form a porous hollow material.

[0050] Through the analysis of the cycle performance and rate performance of the materials of Example 1 and Comparative Examples 1-2, it can be seen that the material prepared in Example 1 has significantly better cycle performance and rate performance than Comparative Examples 1 and 2. This is mainly because the material obtained in Example 1 has a much higher zinc ion storage capacity than Comparative Examples 1 and 2 due to its specific structure.

[0051] The above detailed description of the analytical methods involved in the present invention provides a detailed introduction. It should be noted that the above description is intended solely to help those skilled in the art better understand the methods and concepts of the present invention, and is not intended to limit the relevant content. Without departing from the principles of the present invention, those skilled in the art may make appropriate adjustments or modifications to the present invention, and such adjustments and modifications shall also fall within the scope of protection of the present invention.

Claims

1. A method for preparing an aqueous zinc ion battery electrode material, characterized in that: The steps include: Step 1: Dissolve Ni salt and Mn salt in ethylene glycol and stir magnetically to prepare a NiMn2O4 precursor solution; Step 2: Dissolve the Ce salt in ethylene glycol and mix evenly with magnetic stirring to obtain a Ce salt doped solution; Step 3: Mix the NiMn2O4 precursor solution and the Ce salt solution, disperse and mix them evenly by ultrasonic dispersion, transfer them to a reactor, place the reactor in a microwave reactor, set the reaction temperature to 160-180°C, the reaction time to 1-5h, and the power to 400-800W. After the reaction is completed, cool, centrifuge, filter, wash, and dry to obtain the product; Step 4: Place the product of step 3 in a tube furnace and calcine it at 300-500° C. for 1-2 hours to obtain Ce-NiMn2O4 electrode material.

2. The method for preparing an aqueous zinc ion battery electrode material according to claim 1, wherein in step 1, the Ni salt is selected from one or more of nickel chloride, nickel sulfate, and nickel nitrate.

3. The method for preparing an aqueous zinc ion battery electrode material according to claim 1, wherein in step 1, the Mn salt is selected from one or more of manganese chloride, manganese sulfate, and manganese nitrate.

4. The method for preparing an aqueous zinc ion battery electrode material according to claim 1, wherein in step 2, the Ce salt is selected from one or more of cerium chloride, cerium sulfate, and cerium nitrate.

5. The method for preparing an aqueous zinc ion battery electrode material according to claim 1, wherein the magnetic stirring time in steps 1 and 2 is set to 10-20 min.

6. The method for preparing an aqueous zinc ion battery electrode material according to claim 1, wherein the molar ratio of the three metal salts of Ce salt, Ni salt and Mn salt is (0.02-0.1):1:

2.

7. An aqueous zinc ion battery electrode material obtained by the preparation method of claim 1, characterized in that: The electrode material is Ce-doped NiMn2O4, which presents a porous hollow spherical structure with a diameter ranging from 1.5 μm to 3.5 μm.

8. An aqueous zinc ion battery, characterized in that The electrode material prepared according to claim 1 is used as the positive electrode material of an aqueous zinc ion battery.

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