A kind of high-nickel-type nickel-cobalt lithium manganese oxide precursor with specific morphology and preparation method thereof

Abstract

The invention discloses a high-nickel type lithium Ni-Co manganate precursor with specific morphology. The mean grain size of the primary particle of the precursor is 200-500nm; the granularity D10 of the secondary particle aggregate is not less than 6 microns; D50=11-15 microns, D90 is not more than 30 microns, the degree of sphericity of each of the secondary large particle and the secondary small particle is perfect, and the primary particle is filamentous. The preparation of the precursor comprises the following steps: firstly preparing a soluble mixed salt solution; adding ammonia water as the reaction kettle base solution, and regulating the pH of the base solution; inflating the nitrogen into the reaction kettle and starting the stirring; combining the configured soluble mixed water solution, the alkali and the ammonia water to add in the reaction kettle to perform the stirring reaction, reacting for some time, circularly pumping the early unqualified material into the reaction pump, performing ageing, filter-pressing and washing on the overflow material, drying, screening and then saving. The product disclosed by the invention is good in consistency and has specific morphology; the process efficiency is higher, and the product stability is better.

Description

technical field [0001] The invention belongs to the field of lithium-ion battery materials, and in particular relates to a precursor of nickel-cobalt-lithium-manganese oxide and a preparation method thereof. Background technique [0002] Lithium-ion batteries have the advantages of long cycle life and no memory effect. They have become a new generation of sustainable green power sources and are widely used in many fields such as digital, notebook, and electric vehicles. With the development of the electric vehicle industry, the market has put forward a higher demand for the energy density of lithium-ion batteries, and the improvement of battery energy density depends on the improvement of the performance of battery materials. [0003] Lithium nickel cobalt manganese oxide has broad application prospects in the field of power batteries due to its high capacity per gram, high voltage platform, and good cycle performance. , 622 type, with the increase of nickel content, the ca...

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Problems solved by technology

According to the invention patent CN103274480A, it is mentioned that the use of ammonium sulfate as a complexing agent is used to prepare the precursor Ni of the multi-component cathode material x co 1-x-y-z mn y W z (OH) 2 (0x co y mn z (OH) 2 , but the primary particle morphology of the precursor has not been elaborated and explained. The cycle performance of the positive electrode material depends largely on the internal structure of the material. The more stable the internal structure of the material and the orderly growth of internal particles, the greater the cycle performance of the material. The higher the higher, the structural stability of the positive electrode material depends on the primary particle morphology, primary particle size and internal growth state of the precursor; the invention patents CN105731553A and CN105355907A all mentioned the influence of the primary particle of the precursor on the performance of the finished product, but explained The morphology of the obtained primary particles is limited; and the filamentous morphology is not elaborated; CN105731553A mentions the preparation method of the precursor of the crystal family shape of the primary particles, but the morphology of the precursor, the primary particles are too large, The sphericity of the small particles prepared by this process is poor, and after sintering the finished product, it is not conducive to the subsequent coating treatment. CN105355907A proposes an annual ring structure precursor, but only for lithium-rich materials, and does not explain the high-nickel precursor; CN105118981A Mentioned in the preparation of high nickel type Ni x co y mn z (OH) 2 (0.5≤x≤0.9) precursor, in order to avoid the generation of internal loose fine particles, the gap production process is adopted; although the sphericity of this type of precursor is good, the production efficiency of the gap method is low, and it cannot be applied on a large scale. Moreover, no solutions are proposed for the nucleation of high-nickel precursors prepared in the continuous process

[0004] It can be seen from the above that many existing patents have mentioned the preparation method of the nickel cobalt lithium manganese oxide precursor, and the primary particle morphology of the precursor is involved, but for the morphology of the high nickel precursor, the spherical shape of the particle temperature etc. have not been fully elaborated, and in the preparation method, the influence of reaction temperature on the properties of the precursor is mainly concerned, but the research on other key process parameters in the process is not enough. Generally speaking, the nickel cobalt lithium manganese oxide precursor The product performance of the body still needs to be optimized, and the process efficiency and nucleation effect of its preparation method need to be improved

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