High-magnification monocrystal-like lithium nickel cobalt aluminate positive electrode material with coating layer and preparation method thereof

Abstract

The invention discloses a high-magnification monocrystal-like lithium nickel cobalt aluminate positive electrode material with a coating layer and a preparation method thereof, the preparation methodcomprises the following steps: (1) uniformly mixing a cobalt nickel hydroxide precursor and aluminum hydroxide, then adding lithium hydroxide, and continuously mixing to obtain a mixture; and (2) putting the material into a high-temperature-resistant container, sintering in an oxygen-enriched environment, cooling to room temperature, and sieving to obtain the monocrystal-like lithium nickel cobaltaluminate positive electrode material, (3) mixing the material with cold water, and controlling the washing time and the drying temperature to obtain the washed monocrystal-like lithium nickel cobaltaluminate positive electrode material; and (4) uniformly mixing the materials with a coating agent, continuously sintering under an oxygen-enriched condition, cooling to room temperature, and sievingto obtain a finished product. According to the invention, the stability of the monocrystal-like lithium nickel cobalt aluminate positive electrode material can be improved, so that the cycle performance and the rate capability of the positive electrode material are improved.

Description

technical field [0001] The invention relates to the technical field of lithium-ion batteries, in particular to a high-rate monocrystalline nickel-cobalt lithium aluminate cathode material with a coating layer and a preparation method thereof. Background technique [0002] Lithium-ion batteries, as the most potential energy storage devices, are widely used in consumer electronics, pure electric vehicles, hybrid vehicles, and smart grids. Due to its own structure, the actual usable capacity of lithium cobalt oxide is only half of the theoretical capacity, about 140mAh g -1 In addition, the element cobalt necessary for the preparation of lithium cobalt oxide is also harmful to the human body and the global cobalt element reserves are small and other factors limit the application of lithium cobalt oxide in high-end markets such as pure electric vehicles and high-power electric tools. In order to further develop the application market of lithium-ion batteries and reduce the cost...

AI Technical Summary

Problems solved by technology

The reaction process involves the addition of halogen, which is difficult to completely remove from the material

In addition, due to the addition of sodium ions, the sodium ions will enter the NCA lattice during the sintering process, thereby increasing the degree of cation mixing in the material, which is not conducive to the high rate performance of the material.

[0007] The invention patent with the application number CN201811173363 requires pre-calcining the precursor to become an oxide and then crushing it to D50≤8μm, adding appropriate amount of specific additives such as sodium chloride, potassium chloride, sodium fluoride, potassium fluoride and other chemicals, After that, the single-crystal-like material is obtained through high-temperature sintering; the invention introduces halogen, which is not only difficult to completely remove from the material, but also causes certain damage to the equipment in industrial production, and is not conducive to the healthy development of the environment; the invention involves The synthesis process is too complicated to be suitable for industrial production

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