CN-122010182-A - Alpha-MnO reconstituted from crystalline forms of electrolytic manganese dioxide2Positive electrode material, preparation method and application thereof

Abstract

The invention discloses a method for reconstructing the crystal form of electrolytic manganese dioxide Positive electrode material, and preparation method and application thereof. Based on an Electrolytic Manganese Dioxide (EMD) -oxalic acid-potassium persulfate reaction system, the method takes low-cost EMD as a manganese source and realizes the process parameter regulation and control The directional preparation of the catalyst has the advantages of obtaining a product with high purity and excellent electrochemical performance, and reducing the preparation cost and environmental protection pressure. Prepared by The specific surface area is large, the zinc ion diffusion path is smooth, and the zinc ion diffusion path shows high initial discharge specific capacity and good cycling stability when being applied to the water-based zinc ion battery anode material.

Inventors

• YIN YANHONG
• CHEN RUN
• WANG HAO
• ZHANG HUISHUANG
• DONG HONGYU
• YUE HONGYUN
• YANG YANGE
• YIN XUDONG

Assignees

• 河南师范大学

Dates

Publication Date

20260512

Application Date

20260212

Claims (8)

1. 1. Reconstituted from crystalline form of electrolytic manganese dioxide The preparation method of the positive electrode material is characterized in that the pure phase is prepared based on an electrolytic manganese dioxide-oxalic acid-potassium persulfate reaction system Regulating the pH value of the system to 0.8-1.2, performing reaction in a constant-temperature water bath, and washing and drying after the reaction is finished to obtain the catalyst And a positive electrode material.
2. 2. A method of claim 1 wherein the method comprises the step of The preparation method of the cathode material is characterized in that in the raw material preparation stage, the molar ratio of electrolytic manganese dioxide to oxalic acid to potassium persulfate is 1 (0.43-0.63) (1.03-1.29), wherein the concentration of oxalic acid solution is controlled to be 0.2-1 mol/L, and the concentration of potassium persulfate solution is controlled to be 0.15-0.5 mol/L.
3. 3. A method of claim 2 wherein the method comprises the step of A method for producing a positive electrode material, characterized by comprising the step of electrolyzing manganese dioxide The phase is mainly, and the purity is more than or equal to 90 percent.
4. 4. A method of claim 1 wherein the method comprises the step of The preparation method of the positive electrode material is characterized in that concentrated sulfuric acid is used as a pH regulator.
5. 5. A method of claim 1 wherein the method comprises the step of The preparation method of the positive electrode material is characterized in that when the reaction is carried out in a constant-temperature water bath, the reaction is stirred for 4-10 hours at the rotating speed of 250-600 r/min under the condition of 50-80 ℃.
6. 6. A method as claimed in claim 3, wherein the method comprises the step of The preparation method of the positive electrode material is characterized by comprising the following specific preparation processes: S1, preparing and proportioning raw materials, namely taking electrolytic manganese dioxide as a manganese source, oxalic acid as a crystal face guiding agent, potassium persulfate as an oxidant and concentrated sulfuric acid as a pH regulator; S2, performing constant temperature reaction, namely adding EMD and a certain amount of deionized water into a reaction container, placing the reaction container into a constant temperature water bath at 50-80 ℃, stirring to uniformly disperse solid raw materials to obtain a mixed suspension, slowly adding the prepared potassium persulfate solution and oxalic acid solution, dropwise adding concentrated sulfuric acid, regulating the pH value of the system to 0.8-1.2, and stirring at the rotating speed of 250-600 r/min for reacting for 4-10 hours; S3, after the reaction is finished, cooling the reaction liquid to room temperature, filtering and separating a product, washing a filter cake with deionized water to be neutral, washing the filter cake with absolute ethyl alcohol for 1-3 times, and drying the washed product in a vacuum drying oven at 60-100 ℃ for 6-15 hours to obtain The product is obtained.
7. 7. Reconstituted from crystalline form of electrolytic manganese dioxide A positive electrode material, characterized in that it is produced by the method according to any one of claims 1 to 6.
8. 8. An aqueous zinc ion battery characterized in that the positive electrode material is as defined in claim 6 And the positive electrode material is prepared.

Description

Alpha-MnO 2 anode material reconstructed by electrolytic manganese dioxide crystal form, preparation method and application thereof Technical Field The invention relates to the field of lithium ion battery materials, in particular to a method for reconstructing a crystal form by electrolytic manganese dioxidePositive electrode material, and preparation method and application thereof. Background With the increasing severity of global energy crisis and environmental problems, the development of clean, efficient, sustainable energy storage systems has become an important direction of current technological development. In many electrochemical energy storage technologies, although a lithium ion battery has dominant, potential safety hazards such as lithium resource scarcity, high cost, inflammability and explosiveness of an organic electrolyte exist, and the application of the lithium ion battery in the field of large-scale energy storage is limited. Therefore, it is urgent to find a low-cost, high-safety alternative battery system. Aqueous zinc ion batteries have received attention for their unique advantages. The zinc resource is abundant, the price is low, and the zinc has high theoretical capacity) And low redox potential (-0.76V vs. SHE). More importantly, the aqueous electrolyte is adopted to replace inflammable organic electrolyte, so that the safety of the battery is fundamentally improved, and the manufacturing and packaging processes of the battery are simplified, so that the battery becomes a candidate with potential for large-scale power grid energy storage. In aqueous zinc ion battery systems, the positive electrode material is a critical factor in determining overall battery performance (e.g., capacity, rate capability, and cycle life). Manganese dioxide [ ]) The method has the advantages of rich reserve, environmental protection and high theoretical specific capacity) And the like, is considered as one of the positive electrode materials of the water-based zinc ion battery with great application prospect.There are a variety of crystal configurations (alpha, beta, gamma, delta, etc.), among which,Is favored because of its unique [2 x 2] tunnel structure. The tunnel size (about 4.6A) and zinc ions [ ]) Is of a size (about 0.74A) that matchesProvides an ideal transmission path, and is beneficial to realizing high capacity and excellent multiplying power performance. At present, the current time of the process,The preparation method of (C) mainly comprises a potassium permanganate-manganese sulfate precipitation method (Journal of PHYSICS AND CHEMISTRY of Solids 73 (2012) 1487-1491), a hydrothermal method (Journal of Alloys and Compounds 992 (2024) 174528), a sol-gel method and the like. The precipitation method has the advantages of high raw material reaction rate and simple operation, but has obvious defects that on one hand, the reaction process is easily influenced by concentration and temperature fluctuation, and the crystal form of the product easily appearsMixed phase, low purity, on the other hand, residual in the system、The high-manganese sulfate is easy to adsorb on the surface of a product, multiple times of washing and purification are needed, the process steps and the cost are increased, a large amount of sulfate wastewater can be generated, the residual high-manganese acid radical is needed to be subjected to additional reduction treatment, and the environmental protection pressure is high. Although the hydrothermal method and the sol-gel method can prepare the high-purityHowever, the hydrothermal method needs high-temperature high-pressure equipment, has high energy consumption and large industrial amplification difficulty, and the sol-gel method has high raw material cost, and the gel drying and roasting processes are easy to cause collapse of the product structure and influence the electrochemical performance. Therefore, there is an urgent need to develop a new type of deviceA preparation method of a positive electrode material. Disclosure of Invention Against the prior artThe invention provides a method for preparing a catalyst based on Electrolytic Manganese Dioxide (EMD) -oxalic acid-potassium persulfate reaction system, which has the problems of high raw material cost, poor crystal form controllability, high environmental protection pressure, high industrialization difficulty and the likeThe preparation method takes low-cost EMD as a manganese source and realizes the preparation by regulating and controlling the technological parametersThe directional preparation of the catalyst has the advantages of obtaining a product with high purity and excellent electrochemical performance, and reducing the preparation cost and environmental protection pressure. The invention provides a method for reconstructing the crystal form of electrolytic manganese dioxidePreparation method of positive electrode material, and preparation method of pure phase based on electrolytic manganese dioxide-oxali