Preparation technology of micron-size monocrystalline primary particle ternary cathode material

Abstract

Belonging to the technical field of lithium ion battery cathode materials, the invention discloses a preparation technology of a micron-size monocrystalline primary particle ternary cathode material.The technology includes the steps of: mixing a nickel salt solution, a cobalt salt solution and a manganese salt solution according to a ratio of x:y:z, adding a complexing agent ammonia water, addinga precipitant sodium hydroxide, performing mixing at a temperature of 50-90DEG C to pH of 11-13 so as to obtain a co-precipitate, and subjecting the co-precipitate to solid-liquid separation by a centrifuge to obtain a precursor A; adding a lithium salt into the precursor A, mixing the substances evenly in a high speed mixer, and performing heat treatment to obtain a 0.1-1microm seed crystal small single crystal particle B; and adding the seed crystal small single crystal particle B into the precursor A, controlling the mixing weight ratio of the small single crystal particle B and the precursor A at 1:25-1:10, at the same time performing mixing with a lithium salt, and carrying out solid phase reaction to obtain single crystal particles of 4microm or above. According to the invention, the preparation process is simple and is easy to control, the product has good single crystal morphology, the single crystal particle is 4microm or above, the particle surface is smooth, and the dispersibility is good, therefore the product can be popularized and used in commercial production.

Description

technical field [0001] The invention belongs to the technical field of positive electrode materials of lithium ion batteries, and in particular relates to a preparation process of a micron-sized single crystal primary particle ternary positive electrode material. Background technique [0002] New energy vehicles are the direction of future vehicle development, and power batteries are an important part of new energy vehicles that differ from traditional fuel vehicles. At present, there are two main types of lithium-ion batteries used in the field of new energy vehicles: one is lithium iron phosphate (LFP) battery with positive electrode material, and the other is ternary material battery. Due to the insufficient energy density of lithium iron phosphate, it has gradually been unable to meet the needs of social development; and the high voltage and high energy density of ternary batteries are expected to meet people's needs. [0003] Ternary cathode materials can be synthesize...

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Problems solved by technology

[0003] Ternary cathode materials can be synthesized by a series of processes such as high-temperature solid-phase method, sol-gel method, spray drying method, hydrothermal method, and co-precipitation method. Since the co-precipitation method can achieve uniform mixing at the atomic and molecular levels, it can control The morphology and tap density of materials are widely used in industrial production. In the conventional co-precipitation preparation process, the precursors of ternary materials are synthesized first, and the hydroxide precursors are the most common, namely The soluble salt of the metal element reacts with the strong base precipitant under the action of the complex to form a precursor. The whole process takes a long time and costs high, and the precursor and sintered body are generally regular spherical Or spherical polycrystalline polymers, when the material is used in the positive electrode of lithium-ion batteries, it is easy to break the particles during long-term cycle use or charge storage

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