Method for preparing high-performance rod-like lithium nickelate positive electrode material at ultralow temperature
By reacting lithium fluoride with nickel oxide powder under specific conditions at a temperature below 600°C, a high-performance rod-shaped lithium nickel oxide positive electrode material was successfully prepared, which solved the problems of high preparation temperature and serious lithium source loss in the prior art, and achieved the convenience of process simplification and industrialization.
Patent Information
- Application Number
- CN202510501896.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2025-06-06
AI Technical Summary
In the prior art, when preparing lithium nickelate positive electrode materials, there are problems such as high preparation temperature, serious loss of lithium source and difficult to control particle size, especially when it is difficult to achieve high-performance rod lithium nickelate at temperatures below 600°C.
Lithium fluoride powder is used as the lithium source, and grind and mixed with nickel oxide powder at a certain molar ratio, then heats up to 400-550°C in a specific atmosphere, keeps heat for 0.5-2 hours, and finally cools to room temperature to prepare a high-performance rod-shaped lithium nickel oxide positive electrode material.
It is realized that high-performance rod lithium nickelate positive electrode material is prepared at a temperature below 600°C, which reduces the preparation temperature, simplifies the process, and has no requirements for the reaction atmosphere, making it easy to industrialize.
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Figure CN120097396A_ABST
Abstract
Description
Technical Field
[0001] The invention provides a method for preparing a high-performance rod-shaped lithium nickel oxide positive electrode material at an ultra-low temperature, belonging to the field of positive electrode materials. Background Art
[0002] Lithium nickel oxide has the advantages of high specific capacity, low pollution, moderate price, and good matching with electrolyte, and is considered to be a promising positive electrode material for lithium-ion batteries.
[0003] There are relatively complete and systematic methods for the preparation of lithium nickel oxide positive electrode materials, including solid phase method, coprecipitation method, spray method, sol-gel method, etc. Among them, the solid phase method has been widely studied because of its advantages of easy control of element stoichiometry and large-scale production. However, this method also has the disadvantages of high preparation temperature (≥600℃), which leads to serious loss of lithium source and difficulty in controlling particle size.
[0004] At present, the nickel source for preparing lithium nickelate by solid phase method is basically nickel oxide, while the types of lithium sources are relatively rich, including lithium hydroxide, lithium carbonate, lithium sulfate, lithium bicarbonate, lithium oxide, lithium oxalate, etc. However, the technologies using the above lithium compounds as lithium sources all have the problem of high preparation temperature, specifically 201710124187.X-780℃, 201610736135.3-800~850℃, 201710601941.4-600~750℃, 2017112099350-740~800℃, 2022116479010-850~950℃, 2023102956004-600~700℃, 2024108386723-650℃, 2024109329145-670~750℃.
[0005] Therefore, it is an extremely challenging and significant task to convert nickel oxide into lithium nickelate through a solid phase reaction at a temperature below 600°C. Summary of the invention
[0006] In an accidental experiment, our team discovered that nickel oxide powder reacts with lithium fluoride powder to generate a lithium nickelate phase at a temperature below 600°C. Therefore, based on this discovery and in view of the shortcomings of the prior art, the present invention invented a method for preparing a high-performance rod-shaped lithium nickelate positive electrode material at ultra-low temperature. This is achieved through the following technical solution.
[0007] A method for preparing high-performance rod-shaped lithium nickel oxide positive electrode materials at ultra-low temperature, characterized in that: S1: lithium fluoride powder is used as lithium source and nickel oxide powder is used as nickel source; S2: grinding and mixing lithium fluoride and nickel oxide in a certain molar ratio to obtain a mixed powder of lithium fluoride and nickel oxide; S3: The mixed powder is heated to a suitable reaction temperature in a certain atmosphere, kept warm for a certain period of time, and finally cooled to room temperature to obtain a high-performance rod-shaped lithium nickel oxide positive electrode material.
[0008] The particle size of the powder is no more than 100 μm.
[0009] The certain molar ratio is 1.0-2.0:1.0.
[0010] The grinding and mixing is mechanical stirring, air flow mixing or ultrasonic mixing.
[0011] The certain atmosphere is a vacuum atmosphere, an inert atmosphere, an oxidizing atmosphere, or a reducing atmosphere.
[0012] The suitable reaction temperature is 400-550°C.
[0013] The insulation time is 0.5 to 2 hours.
[0014] The invention has the advantages of low preparation temperature, no requirement on reaction atmosphere, simple process and easy industrialization. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 This is the XRD diagram of the lithium nickel oxide prepared in Example 1. Figure 2 This is a SEM image of the lithium nickel oxide prepared in Example 1. DETAILED DESCRIPTION
[0015] The present invention will be further described below in conjunction with specific implementation modes.
[0016] Example 1 The method for preparing high-performance rod-shaped lithium nickel oxide positive electrode materials at ultra-low temperature comprises the following steps: The lithium fluoride powder with a particle size of 60 to 100 μm is used as the lithium source, and the nickel oxide powder with a particle size of 50 to 100 μm is used as the nickel source; the lithium fluoride and the nickel oxide are manually ground and mixed (mechanically stirred) at a molar ratio of 1:1 to obtain a mixed powder of lithium fluoride and nickel oxide; the mixed powder is heated to 550°C in air, kept warm for 1 hour, and finally cooled to room temperature to obtain a high-performance rod-shaped lithium nickel oxide positive electrode material. The XRD and SEM of the lithium nickel oxide are shown in the attached Figure 1 and attached Figure 2 .
[0017] Example 2 The method for preparing high-performance rod-shaped lithium nickel oxide positive electrode materials at ultra-low temperature comprises the following steps: Lithium fluoride powder with a particle size of 150 to 500 nm is used as a lithium source, and nickel oxide powder with a particle size of 100 to 300 nm is used as a nickel source; lithium fluoride and nickel oxide are mixed in a fluidized bed (air flow mixing) at a molar ratio of 1.5:1 to obtain a mixed powder of lithium fluoride and nickel oxide; the mixed powder is heated to 450°C in argon (inert atmosphere), kept warm for 1.5 hours, and finally cooled to room temperature to obtain a high-performance rod-shaped lithium nickel oxide positive electrode material.
[0018] Example 3 The method for preparing high-performance rod-shaped lithium nickel oxide positive electrode materials at ultra-low temperature comprises the following steps: Lithium fluoride powder with a particle size of 20 to 50 nm is used as a lithium source, and nickel oxide powder with a particle size of 30 to 70 nm is used as a nickel source; lithium fluoride and nickel oxide are mixed in an ultrasonic liquid phase at a molar ratio of 2:1 (ultrasonic mixing) to obtain a mixed powder of lithium fluoride and nickel oxide; the mixed powder is heated to 400°C in an atmosphere with an argon-hydrogen ratio of 2:7 (reducing atmosphere), kept warm for 0.5h, and finally cooled to room temperature to obtain a high-performance rod-shaped lithium nickel oxide positive electrode material. Electrochemical performance test
[0019] The test items of the present invention are as follows:
[0020] Preparation and performance test of button half-cell:
[0021] The preparation method of button half-cell is as follows: first, active positive electrode materials lithium nickelate, PVDF and carbon black are mixed in a mass ratio of 8:1:1, and a proper amount of NMP is added and stirred to form a battery slurry, and then the battery slurry is evenly coated on a copper foil and placed in a 100°C oven for 12 hours. After drying, the positive electrode sheets are cut into round sheets of uniform size, and the loading amount of active substances on the sheets is 10-20 mg / cm 2 The prepared positive electrode sheet was placed in a vacuum glove box, and the metal lithium sheet was used as the negative electrode, and assembled into a button-type half-cell with the separator, electrolyte and other components. After the assembly was completed, the battery was placed on a battery tester for electrical performance testing. The test environment conditions were a constant room temperature of 25°C, and the charge cut-off voltage and discharge cut-off voltage were 4.5V and 3.0V respectively.
[0022] The specific test steps of 0.1C discharge capacity and first discharge efficiency are as follows: the button half-cell prepared above is charged to the charge cut-off voltage at a 0.1C rate and then discharged to the discharge cut-off voltage for testing.
[0023] The specific steps of the 1C cycle 50-week capacity retention rate test are as follows: the button half-cell prepared above is activated twice by step (2), and then charged to the charge cut-off voltage and discharged to the discharge cut-off voltage at a 1C rate for 50 cycles to obtain the test result.
[0024] The electrochemical performance test results are shown in Table 1. Table 1 Electrochemical performance test results of each embodiment
Claims
1. A method for preparing high-performance rod-shaped lithium nickel oxide positive electrode materials at ultra-low temperature, characterized in that: S1: lithium fluoride powder is used as lithium source and nickel oxide powder is used as nickel source; S2: grinding and mixing lithium fluoride and nickel oxide in a certain molar ratio to obtain a mixed powder of lithium fluoride and nickel oxide; S3: The mixed powder is heated to a suitable reaction temperature in a certain atmosphere, kept warm for a certain period of time, and finally cooled to room temperature to obtain a high-performance rod-shaped lithium nickel oxide positive electrode material.
2. The method for preparing high-performance rod-shaped lithium nickel oxide positive electrode material at ultra-low temperature according to claim 1, characterized in that: The particle size of the powder is no more than 100 μm.
3. The method for preparing high-performance rod-shaped lithium nickel oxide positive electrode material at ultra-low temperature according to claim 1, characterized in that: The certain molar ratio is 1.0-2.0:1.
0.
4. The method for preparing high-performance rod-shaped lithium nickel oxide positive electrode material at ultra-low temperature according to claim 1, characterized in that: The grinding and mixing is mechanical stirring, air flow mixing or ultrasonic mixing.
5. The method for preparing high-performance rod-shaped lithium nickel oxide positive electrode material at ultra-low temperature according to claim 1, characterized in that: The certain atmosphere is a vacuum atmosphere, an inert atmosphere, an oxidizing atmosphere, or a reducing atmosphere.
6. The method for preparing high-performance rod-shaped lithium nickel oxide positive electrode material at ultra-low temperature according to claim 1, characterized in that: The suitable reaction temperature is 400-550°C.
7. The method for preparing high-performance rod-shaped lithium nickel oxide positive electrode material at ultra-low temperature according to claim 1, characterized in that: The insulation time is 0.5 to 2 hours.