Magnesium ion doped gradient nickel cobalt lithium manganate anode material and preparation method thereof

Abstract

The invention relates to a magnesium ion doped gradient nickel cobalt lithium manganate anode material and a preparation method thereof. The chemical formula of the anode material is LiNixCoyMnzMg (1-x-y-z) O2, wherein x is more than 0.5 and less than 0.9, y is more than 0.05 and less than 0.20, z is more than 0.05 and less than 0.30, and 1-x-y-z is more than 0; the nickel content is gradually reduced from the center to the surface of the anode material particles, the manganese content is gradually increased from the center to the surface of the anode material particles, and the contents of cobalt and magnesium are uniformly distributed in the anode material. The invention also discloses a preparation method of the anode material. The anode material has the advantages that the structure and the cycle performance are stable in the charging and discharging process, the capacity is higher, and the charging and discharging reaction is highly reversible. The method has the advantages of simple process, low reaction temperature and low raw material cost, and is suitable for industrial production.

Description

technical field [0001] The invention relates to a nickel-cobalt lithium manganese oxide cathode material and a preparation method thereof, in particular to a magnesium ion-doped gradient nickel-cobalt lithium manganese oxide cathode material and a preparation method thereof. Background technique [0002] With the increase of people's demand for portable devices and the development of commercial lithium-ion batteries, the current mainstream NCM523 and NCM622 can no longer meet people's demand for lithium-ion battery capacity. Although the high-nickel NCM811 can meet the energy density required by electric vehicles, its cycle performance is unstable and its capacity decays quickly, making it difficult to achieve large-scale commercial applications. [0003] CN104201366A discloses a method for preparing a high-safety and high-compacted-density lithium nickel-cobalt-manganese oxide NCM523 ternary material. During the sintering process of the material, an appropriate amount of ma...

AI Technical Summary

Problems solved by technology

[0002] With the increase of people's demand for portable devices and the development of commercial lithium-ion batteries, the current mainstream NCM523 and NCM622 can no longer meet people's demand for lithium-ion battery capacity.

Although the high-nickel NCM811 can meet the energy density required by electric vehicles, its cycle performance is unstable and its capacity decays quickly, making it difficult to achieve large-scale commercial applications.

[0003] CN104201366A discloses a method for preparing a high-safety and high-compacted-density lithium nickel-cobalt-manganese oxide NCM523 ternary material. During the sintering process of the material, an appropriate amount of magnesium compound is added for doping to increase the ternary material of nickel-cobalt-manganese oxide lithium NCM523. The size of the single crystal particle in the element material particle can be increased, thereby increasing the compactness of the particle, forming a firm microstructure change, and finally improving the compaction density of the lithium nickel cobalt manganese oxide NCM523 positive electrode material; although this method is simple, it can effectively improve the material Compacted density, but low capacity, 0.5C gram capacity is only 151-154mAh / g, 1C gram capacity is only 144-148 mAh / g

However, in this experimental process, after the positive electrode powder with the inner core is prepared, further coating methods such as precipitation and sintering are required, and the process steps are too complicated

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