Preparation method of ternary Ni-Co-Mn precursor and ternary Ni-Co lithium manganate material

Abstract

The invention discloses a preparation method of a ternary Ni-Co-Mn precursor and a ternary Ni-Co lithium manganate material. The preparation method of the ternary Ni-Co-Mn precursor comprises the following steps: (1) preparing a Ni-Co-Mn hydroxide solid solution through a co-precipitation method by taking a Ni-Co-Mn salt solution as a raw material and an alkaline solution as a precipitator; (2) sintering the Ni-Co-Mn hydroxide solid solution, thus obtaining a Ni-Co-Mn oxide precursor; (3) drying after sanding and dispersing the Ni-Co-Mn oxide precursor obtained in step (2) by using a sand mill, thus obtaining the ternary Ni-Co-Mn precursor. The preparation method of the ternary Ni-Co lithium manganate material comprises the following steps: adding the Ni-Co-Mn oxide precursor into a lithium source, entering a ball mill for uniformly mixing, and entering an atmosphere furnace for sintering, thus obtaining a ternary material after sintering, i.e., the ternary Ni-Co lithium manganate material. A ternary anode material prepared through the preparation method is high in specific capacity and high in compaction density, the Mn dissolution quantity of an electrode plate in a total batterycan be reduced to a large extent, and high / low-temperature cycle performance can also be effectively increased.

Description

technical field [0001] The invention relates to the technical field of lithium ion battery materials, in particular to a preparation method of a ternary nickel-cobalt-manganese precursor and a ternary nickel-cobalt-manganese oxide material. Background technique [0002] There are currently two typical types of ternary materials produced in the lithium battery material industry. One is a spherical secondary particle aggregate ternary nickel-cobalt-manganese material. The preparation technology is as follows: dissolving nickel sulfate, cobalt sulfate and manganese sulfate to form a mixed solution, adding ammonia water and sodium hydroxide to a stirring tank at a certain stirring speed. Among them, ammonia water plays a complexing role, so that the three ions of nickel, cobalt, and manganese maintain similar concentrations. Sodium hydroxide provides hydroxide. After the nickel hydroxide cobalt manganese co-precipitation nuclei are obtained by precipitation, the complexed nic...

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Problems solved by technology

First of all, the concentration of each solution and the feeding speed control are slightly shifted, and the obtained secondary balls may have large or small primary particles, resulting in loose secondary balls, low ball forming rate, irregular shape, and segregation of elements inside the co-precipitation. Quality control is difficult; secondly, the form and size of the stirring paddle and the size of the kettle body are also very high. From small scale to production, the equipment selection parameters and process parameters are poor in portability, and the stirring control is biased. The obtained secondary balls may The sphericity is poor, and it may also be hollow inside, which will have a serious negative impact on the later ternary material coating roll pressing

Thirdly, the secondary ball itself is an agglomerate, which causes scratches, bubbles, and wrinkles to be broken during the rolling process of the pole piece, and the rolling pressure is limited, and the energy density of the material is low

The contact area between the secondary ball ternary material and the electrolyte is large, the side reaction is large, and the problem of short cycle life often occurs

At the same time, this method may cause three-element segregation

When the large single crystal ternary precursor is sintered and reacted with the lithium source, it is difficult for the lithium source to enter the large radius single crystal precursor, resulting in a low firing rate, and the electrochemical performance is generally lower than that of the secondary spherical ternary material

The obtained ternary material particles are large single crystals, with a large ion migration radius and poor performance at high and low temperatures

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