Preparation method of nickel-manganese binary composite positive electrode material

Abstract

The invention relates to the technical field of lithium batteries, in particular to a preparation method of a nickel-manganese binary composite positive electrode material. According to the preparation method, the nickel salt and the manganese salt are mixed according to a certain proportion, and the pH value is adjusted in the heating and stirring process, so that the reaction process can be effectively controlled, and the purity and the quality of the nickel-manganese binary composite positive electrode material are improved. Meanwhile, the preparation method is relatively low in cost, simple to operate and suitable for large-scale production.

Description

Technical Field

[0001] The invention relates to the technical field of lithium batteries, and in particular to a method for preparing a nickel-manganese binary composite positive electrode material. Background Art

[0002] In lithium batteries, the cathode material is one of the key factors affecting battery performance. Traditional lithium battery cathode materials mainly include lithium cobalt oxide, lithium nickel oxide and lithium manganese oxide. However, these materials have some problems, such as high cost and less than ideal safety, which limit their further application. Therefore, the development of a low-cost and high-safety cathode material has become the current research focus. Summary of the invention

[0003] The present invention provides a method for preparing a nickel-manganese binary composite positive electrode material, aiming to solve the above problems. The positive electrode material has high energy density, long life and good safety, and the preparation method is simple and low in cost.

[0004] The present invention is achieved through the following technical solutions: A method for preparing a nickel-manganese binary composite positive electrode material comprises the following steps: (1) mixing nickel salt and manganese salt in a certain proportion to obtain a mixed salt solution; (2) adding an appropriate alkaline substance to the mixed salt solution to adjust the pH value to a predetermined range; (3) heating and stirring the mixed solution to allow the alkaline substance to react with the mixed salt solution to form a nickel-manganese binary composite positive electrode material; (4) Filter, wash and dry the generated precipitate to obtain a nickel-manganese binary composite positive electrode material.

[0005] Compared with the prior art, the present invention has the following beneficial effects: In the preparation method of the present invention, by mixing nickel salt and manganese salt in a certain proportion and adjusting the pH value during heating and stirring, the reaction process can be effectively controlled to improve the purity and quality of the nickel-manganese binary composite positive electrode material. At the same time, the preparation method has low cost, simple operation, and is suitable for large-scale production. DETAILED DESCRIPTION

[0006] The embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention.

[0007] Example 1 The method for preparing the nickel-manganese binary composite positive electrode material of the present invention comprises the following steps: (1) Mix nickel salt and manganese salt in a certain proportion to obtain a mixed salt solution: In this step, we need to mix nickel salt and manganese salt in a certain proportion to obtain a mixed salt solution. This proportion can be determined according to the actual application scenario and performance requirements. For example, we can control it by controlling the mass ratio or molar ratio of nickel salt and manganese salt. The preparation of mixed salt solutions usually needs to be carried out in appropriate solvents to promote the dissolution and mixing of salts. Common solvents include water, organic solvents, etc., and the specific selection should be made according to actual conditions. After the mixed salt solution is prepared, we also need to perform further filtration and washing to ensure the quality and purity of the positive electrode material.

[0008] (2) Add appropriate alkaline substances to the mixed salt solution and adjust the pH value to the predetermined range: Adding appropriate alkaline substances to the mixed salt solution can adjust the pH value to a predetermined range. This alkaline substance can be a hydroxide, an alkaline solution or other alkaline substances, such as sodium hydroxide, potassium hydroxide, etc. By adjusting the pH value, we can control the physical and chemical properties such as the morphology and structure of the nickel-manganese binary composite positive electrode material. In the process of adding alkaline substances, we need to pay attention to controlling the addition speed and concentration to avoid uneven precipitation or crystallization due to excessively violent reactions.

[0009] (3) The mixed solution is heated and stirred to allow the alkaline substance to react with the mixed salt solution to form a nickel-manganese binary composite positive electrode material: In this step, we heat and stir the mixture to allow the alkaline substance to fully react with the mixed salt solution to generate a nickel-manganese binary composite positive electrode material. Heating and stirring can promote the reaction and improve the quality and performance of the material. During the heating and stirring process, we need to control parameters such as temperature and stirring speed to ensure the stability and uniformity of the reaction. At the same time, we also need to pay attention to prevent excessive foaming or other abnormal conditions in the mixture, and take appropriate measures to deal with them in a timely manner.

[0010] (4) Filter, wash and dry the generated precipitate to obtain a nickel-manganese binary composite positive electrode material: After the reaction is completed, we need to filter, wash and dry the generated precipitate to obtain the nickel-manganese binary composite positive electrode material. Filtration can remove impurities and uneven precipitates in the solution and improve the quality and purity of the material. Washing is to remove impurities and residues attached to the surface of the material and improve the electrochemical properties of the material. Drying is to remove solvents such as water in the material to obtain a positive electrode material with a certain shape and structure. During the processing, we need to control the conditions and parameters of filtration, washing and drying to ensure that high-quality and high-performance nickel-manganese binary composite positive electrode materials are obtained.

Claims

1. A method for preparing a nickel-manganese binary composite positive electrode material, characterized in that: The following steps are involved: (1) mixing nickel salt and manganese salt in a certain proportion to obtain a mixed salt solution; (2) adding an appropriate alkaline substance to the mixed salt solution to adjust the pH value to a predetermined range; (3) heating and stirring the mixed solution to allow the alkaline substance to react with the mixed salt solution to form a nickel-manganese binary composite positive electrode material; (4) Filter, wash and dry the generated precipitate to obtain a nickel-manganese binary composite positive electrode material.

2. The method for preparing the nickel-manganese binary composite positive electrode material according to claim 1, characterized in that: The ratio of nickel:cobalt:manganese is 1:1:

1.

3. The method for preparing the nickel-manganese binary composite positive electrode material according to claim 1, characterized in that: The hydroxide is sodium hydroxide or potassium hydroxide.

4. The method for preparing the nickel-manganese binary composite positive electrode material according to claim 1, characterized in that: The mixed solution is heated and stirred to allow the hydroxide to react with the mixed salt solution to form lithium nickel cobalt manganese oxide precipitate.

5. The method for preparing the nickel-manganese binary composite positive electrode material according to claim 1, characterized in that: By heating and stirring, the reaction between the hydroxide and the mixed salt solution can be promoted to generate lithium nickel cobalt manganese oxide precipitate.

6. The method for preparing the nickel-manganese binary composite positive electrode material according to claim 1, characterized in that: In step (4), the generated lithium nickel cobalt manganese oxide precipitate needs to be filtered, washed and dried.

7. The method for preparing the nickel-manganese binary composite positive electrode material according to claim 1, characterized in that: In step (4), impurities in the precipitate, such as unreacted salt substances, etc., can be removed by filtering and washing.

8. The method for preparing the nickel-manganese binary composite positive electrode material according to claim 1, characterized in that: In step (4), water in the precipitate can be removed by drying to obtain a dry lithium nickel cobalt manganese oxide positive electrode material.