What is the manufacture method of the ternary anode material of lithium-ion batteries?

Regarding industrialized manufacturing and mass production series of material for lithium ion battery, this article mainly introduces related synthesis methods and technical means of anode materials. Compared with the other three main materials, the industrial production steps of anode materials are more than the other, and the synthetic methods are relatively complicated. Its controlling of the temperature, environment, impurity content are also severe. The major anode materials are lithium cobaltite, lithium manganite, lithium iron phosphate, ternary materials, etc.. Because the current high energy density of the battery positive electrode materials are different proportions of ternary materials, this article will start with ternary materials, and introduce the industrial production methods of materials.

The origin of ternary materials:

The ternary materials can be considered as the first doping research in the 1990s, such as the doping of LiCoO2, LiNiO2, etc., and the study of doping Co in LiNiO2 to form LiNi1-xCoxO2 series cathode materials in the late 1990s. Researchers have conducted studies on the doping of Mg, Al and Mn in LiNi1-xCoxO2. French Saft-LiNi1-x-yCoxAlyO2 and LiNi1-x-yCoxMgyO2, but the early Li (Ni, Co, MN) O2 did not clarify the reaction mechanism and adopt the appropriate preparation method. At the beginning of the 21st century, Ohzuku from Japan and Canada J.R.Dahn from Canada utilized A series of Li (Ni, Co, Mn) O2 compounds prepared by hydroxide precipitation. Among them, nickel is the main electrochemically active element, and manganese guarantees the structural stability and thermal stability of the material. Cobalt has an irreplaceable role in reducing the electrochemical polarization and improving the rate characteristics of the material. Ternary materials have high specific capacity, good cycle performance, stable structure, reliable safety and moderate cost. In the basic research of the laboratory, no obvious shortcomings of the material found.

It also can been seen from the development roadmap of the positive electrode material that the development of the ternary material plays an important role in improving the energy density of the entire power battery.

Synthesis method of ternary materials:

First, show the thermal stability of different materials. It can been seen from the figure that as the nickel content increases, the thermal stability of the entire positive electrode material decreases and it is necessary to find a balance point in performance and safety, and not blindly improve Use energy density to apply unsafe materials.

The previous figures simply show the process flow of the ternary material and the intermediate control points. Of course, the precursor of a good ternary material is also very important. The synthesis process of the pre-precursor will briefly introduced below.

Firstly, a certain concentration of metal ion mixed solution is arranged according to the stoichiometric ratio. A certain concentration of ammonia-alkali mixed solution used as a precipitating agent and complexing agent, and the reaction vessel is continuously subjected to nitrogen gas to carry out the reaction. Composite precipitate produced by adjusting the pH value of the solution. the precursor directly obtained after being filtered, washed, and vacuum dried. It involves the selection of precipitants, the use of complexing agents, the choice of feeding mode, the control of the reaction atmosphere, etc.

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