Aqueous zinc ion battery electrode material as well as preparation and application thereof

Abstract

The invention relates to an aqueous zinc ion battery electrode material and a preparation method and application thereof.The electrode material is Ce-doped Ni Mn2O4 and is of a porous hollow spherical structure, and the diameter of the spherical structure ranges from 1.5 micrometers to 3.5 micrometers. The preparation method comprises the steps that Ni salt and Mn salt are dissolved in ethylene glycol, and a precursor solution of the Ni Mn2O4 is obtained; dissolving Ce salt into ethylene glycol to obtain a Ce salt-doped solution; the preparation method comprises the following steps: uniformly mixing a precursor solution of Ni Mn2O4 and a Ce salt solution, transferring into a reaction kettle, reacting in a microwave reactor, calcining at 300-400 DEG C after the reaction is finished, and doping Ce into crystal lattices of Ni Mn2O4 to generate oxygen vacancies so as to improve the conductivity; due to the porous hollow special structure, the contact specific surface area of the material and an electrolyte is effectively increased, so that more active sites can be provided for 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 with lithium-ion batteries (LIBs), aqueous zinc-ion batteries (AZIBs) have the advantages of safety, environmental protection, high conductivity, high specific capacity, and good rate performance, and have received widespread attention in the field of new energy storage. At present, the positive electrode materials of aqueous zinc-ion batteries mainly include manganese-based materials, vanadium-based materials, Prussian blue, etc., and the types are relatively limited. Therefore, designing and developing positive electrode materials with high capacity, high rate, and high cycle performance is the 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 an aqueous zinc ion battery. 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 to 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 an aqueous zinc ion battery, at 0.2Ag -1 At a current density of 349 mAh g -1 The 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 interface interaction between the different two phases, which realizes the fast ion diffusion kinetics and high cycle stability of the positive electrode of the rechargeable aqueous zinc ion battery, but the material composition is complex and the cost is high; Chinese patent document CN117393707A discloses a MnCO3 / Mn3O4 heterostructure material and a preparation method and application. Manganese acetate and urea are used as raw materials, and the MnCO3 / Mn3O4 heterostructure material is prepared by a one-step solvothermal method. MnCO3 and Mn3O4, two materials with similar crystal structures, are compounded. Nanospheres of MnCO3 and Mn3O4 constitute nanosheets, and the nanosheets are stacked on each other. The nanosheets close to the "core" position are squeezed to form a bow-tie-like structure. The nanosheet layer in the structure exposes more active sites, which is conducive to the insertion / embedding of zinc ions between the layers. The material has good dispersibility, but 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 Ni Mn2O4, which presents a porous hollow spherical structure, the diameter of the spherical structure ranges from 1.5 μm to 3.5 μm, and 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: dissolving the Ce salt in ethylene glycol and mixing evenly by magnetic stirring to obtain a Ce salt doped solution;

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

[0009] Step 4: The product obtained in step 3 is calcined 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] Wherein, 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] The present application utilizes a microwave-solvothermal method to introduce Ce element doping into a NiMn2O4 precursor solution, thereby preparing a porous hollow spherical structure Ce-doped NiMn2O4 electrode material, wherein Ce is doped into the NiMn2O4 lattice to generate oxygen vacancies, thereby improving the conductivity; the special porous hollow structure effectively increases the contact specific surface area between the material and the electrolyte, thereby providing more active points 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 The 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 The 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 described embodiments 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 creative work 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 min to prepare a NiMn2O4 precursor solution;

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

[0026] Step 3: Mix the precursor solution of NiMn2O4 and the cerium nitrate solution, mix them evenly by ultrasonic dispersion, transfer them to a reaction kettle, place them in a microwave reactor, set the reaction temperature to 180°C, the reaction time to 2h, the power to 600W, cool after the reaction, 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 min to prepare a NiMn2O4 precursor solution;

[0030] Step 2: Dissolve 0.01 mol cerium nitrate in 20 mL ethylene glycol, stir magnetically for 20 min to mix evenly, and obtain a doped cerium nitrate solution;

[0031] Step 3: Mix the precursor solution of NiMn2O4 and the cerium nitrate solution, mix them evenly by ultrasonic dispersion, transfer them to a reaction kettle, place them in a microwave reactor, set the reaction temperature to 180°C, the reaction time to 2h, the power to 600W, cool after the reaction, 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: dissolving nickel nitrate and manganese chloride in 45 mL of ethylene glycol at a molar ratio of 1:2, wherein the nickel nitrate is 0.15 mol and the manganese chloride is 0.3 mol, and magnetically stirring for 20 min to prepare a NiMn2O4 precursor solution;

[0035] Step 2: Dissolve 0.0075 mol cerium nitrate in 20 mL ethylene glycol, stir magnetically for 20 min to mix evenly, and obtain a doped cerium nitrate solution;

[0036] Step 3: Mix the precursor solution of NiMn2O4 and the cerium nitrate solution, mix them evenly by ultrasonic dispersion, transfer them to a reaction kettle, place them in a microwave reactor, set the reaction temperature to 180°C, the reaction time to 3h, the power to 600W, cool after the reaction, 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 min to prepare a NiMn2O4 precursor solution;

[0040] Step 2: Transfer the Ni Mn2O4 precursor solution to a reaction kettle, place it in a microwave reactor, set the reaction temperature to 180°C, the reaction time to 2h, the power to 600W, cool after the reaction, 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 Solvothermal 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 min to prepare a NiMn2O4 precursor solution;

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

[0045] Step 3: Mix the precursor solution of NiMn2O4 and the cerium nitrate solution, 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 2h, 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 the pieces were cut into pieces after vacuum drying 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 analysis of the SEM image of Example 1, it can be seen that the final morphology of the product is a porous hollow spherical structure, and the diameter range of the spherical structure is 1.5μm-3.5μm; using the method of Comparative Example 1, the final material is a block structure with a concave-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 together, and it is difficult to form a porous hollow material if any one of these factors is eliminated.

[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 specific implementation method part specifically introduces the analytical method involved in the present invention. It should be noted that the above introduction is only to help those skilled in the art better understand the method and ideas of the present invention, rather than limiting the relevant content. Without departing from the principle of the present invention, those skilled in the art may also make appropriate adjustments or modifications to the present invention, and the above adjustments and modifications shall also belong to the protection scope 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: dissolving Ni salt and Mn salt in ethylene glycol and stirring with a magnetic force to prepare a Ni Mn2O4 precursor solution; Step 2: dissolving the Ce salt in ethylene glycol and mixing evenly by magnetic stirring to obtain a Ce salt doped solution; Step 3: Mix the Ni Mn2O4 precursor solution and the Ce salt solution, 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, the power to 400-800W, cool after the reaction, 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 h 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. according to the preparation method of a kind of aqueous zinc ion battery electrode material according to claim 1, the magnetic stirring time in steps 1 and 2 is set to 10-20min.

6. According to the aqueous zinc ion battery electrode material of claim 1, 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, and the diameter of the spherical structure ranges from 1.5μm to 3.5μm.

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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