High-nickel core-shell structure gradient nickel-cobalt-manganese ternary cathode material and preparation method thereof

Abstract

A high-nickel core-shell structure gradient nickel-cobalt-manganese ternary cathode material and a preparation method thereof, wherein the ternary cathode material is LiNixCoyMn (1- X- Y) O2, wherein,0.70 <= x <= 0. 85, 0.05 <= y<= 0. 20, 1-X-Y > 0, which is composed of high nickel initial nucleus, middle layer and shell; The nickel element distributes uniformly in the high nickel initial nucleusand gradually decreases from the middle layer to the crust, the cobalt element distributes uniformly in the high nickel initial nucleus, the middle layer and the crust, and the manganese element increases gradually from the middle layer to the crust. The invention also discloses a preparation method of the ternary cathode material. The ternary cathode material prepared by the invention is assembled into a battery, which has high discharge specific capacity and good cycle and rate performance. The method of the invention is simple in process and low in cost, and is suitable for industrial production.

Description

technical field [0001] The invention relates to a nickel-cobalt-manganese ternary positive electrode material and a preparation method thereof, in particular to a nickel-cobalt-manganese ternary positive electrode material with a high nickel core-shell structure gradient and a preparation method thereof. Background technique [0002] In the 21st century, the problem of large-scale energy shortage and environmental pollution worldwide has become increasingly serious, forcing people to seek green power systems that can replace traditional fossil energy and store new energy (solar energy, wind energy, nuclear energy, etc.). Lithium-ion batteries are widely used in devices such as mobile phones, digital cameras and portable personal computers due to their excellent energy density, rate performance and long service life, and their application targets are shifting from small mobile devices to large electric vehicle batteries Series, such as vehicle batteries for pure electric vehi...

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Problems solved by technology

Although this method uses the co-precipitation method to prepare the ternary cathode material, and uses fluorine and magnesium doping to improve its cycle and rate performance, but the synthesis process is cumbersome, which is not conducive to large-scale commercial production

[0005] Usually, in order to obtain a high specific capacity, the proportion of nickel in the ternary material is increased. However, the rate and cycle performance of the high-nickel ternary material are poor. Therefore, how to achieve a high capacity density while the ternary material has Relatively good cycle and rate performance has become one of the research focuses of researchers

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