High-performance lithium nickel cobalt aluminate positive electrode material and preparation method thereof

Abstract

The invention discloses a high-performance lithium nickel cobalt aluminate positive electrode material and a preparation method thereof. According to the high-performance lithium nickel cobalt aluminate positive electrode material and the preparation method thereof, the feeding rate and the pH value of a reaction system are controlled to be at a higher level at the earlier stage in the preparationprocess of a precursor, so that the reaction system rapidly nucleates and forms a large amount of seed crystals; the feeding rate and the pH value of the reaction system are properly decreased in thelater period, so that crystal nuclei slowly grows up, and therefore the nickel cobalt aluminum hydroxide precursor with uniform particle height is prepared; and high-valence metal ions are introducedinto the surface of the precursor, and finally the precursor and lithium hydroxide monohydrate are calcined in a two-stage sintering mode so as to obtain the lithium nickel cobalt aluminum oxide positive electrode material. The high-performance lithium nickel cobalt aluminum oxide positive electrode material and the preparation method thereof have the advantages that the electrochemical performance, the structural stability and the cycling stability of the lithium nickel cobalt aluminate positive electrode material are improved, the improvement effect is remarkable, the overall performance ofthe positive electrode material of a lithium battery can be improved, in addition, the operation is simple, industrialization is easy, and the lithium nickel cobalt aluminate positive electrode material and the preparation method thereof are suitable for being popularized and used in the field.

Description

technical field [0001] The invention belongs to the technical field of battery materials, and relates to a lithium battery cathode material, in particular to a high-performance nickel-cobalt lithium aluminate cathode material and a preparation method thereof. Background technique [0002] At present, automobile fuel oil has accounted for 40% of my country's oil consumption, which not only accelerates the depletion of oil resources, but also has a huge impact on the environment due to the exhaust pollutants it emits. In recent years, with the entry of automobiles into households, automobile exhaust emissions have become the main source of air pollution in large and medium-sized cities in my country. Therefore, limited oil resources and environmental pollution have become bottlenecks restricting the development of the automobile industry, and one of the effective ways to solve fuel shortages and environmental pollution is to develop electric vehicles. The key technology is to ...

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Problems solved by technology

However, the cycle stability of nickel-cobalt-lithium-aluminate cathode material is poor. This is because most of the industrial nickel-cobalt-lithium aluminate cathode materials are prepared by hydroxide co-precipitation method, and the precipitation process is very easy to form fine particles. Particles will have a great impact on the cycle stability of the material, especially the cycle stability at high rates (fast charge and discharge), which greatly affects the application of nickel-cobalt lithium aluminate cathode materials as cathode materials for lithium-ion batteries. limits

In order to improve the cycle stability of nickel-cobalt lithium aluminate cathode materials and further improve their electrochemical performance, various modification processes (including coating, doping, designing concentration gradients, designing new core-shell structures, etc.) The preparation of lithium cobalt aluminate positive electrode materials, however, did not achieve good results

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