Wet-method zirconium-doped concentration-gradient nickel-cobalt-aluminum ternary precursor and preparation method thereof

Abstract

The invention discloses a wet-method zirconium-doped concentration-gradient nickel-cobalt-aluminum ternary precursor and a preparation method thereof. The nickel-cobalt-aluminum ternary precursor hasa chemical general formula of NixCoyAlz(OH)2, wherein x+y+z=1, 0.3<=x<=0.9, 0.01<=y<=0.4, and 0.01<=z<=0.4; the Zr element accounts for 0.001%-3% of the total mass of the nickel-cobalt hydroxide precursor, the ternary precursor consists of three layers, and the inner layer is a zirconium-doped nickel-cobalt binary precursor with a molecular formula of NixCoy(OH)2; and the outer layer is a zirconium-doped nickel-cobalt-aluminum ternary precursor with a molecular formula of NixCoyAlz(OH)2, and the intermediate layer is a concentration-gradient precursor between the zirconium-doped nickel-cobaltbinary precursor and the zirconium-doped nickel-cobalt-aluminum ternary precursor. The invention also includes the method for preparing the nickel-cobalt-aluminum ternary precursor. The zirconium-doped nickel-cobalt-aluminum ternary precursor has a narrow particle size distribution and good particle morphology, the doped element is distributed uniformly through complex controlled crystallizing co-precipitation, and a positive-electrode precursor prepared from the zirconium-doped nickel-cobalt-aluminum ternary precursor has high specific capacity, good cycling stability, good processability andstable performance.

Description

technical field [0001] The invention relates to the technical field of manufacturing a zirconium-doped concentration gradient nickel-cobalt-aluminum ternary precursor, in particular to a wet-process zirconium-doped concentration gradient nickel-cobalt-aluminum ternary precursor and a preparation method thereof. Background technique [0002] As a new type of green battery, lithium-ion batteries have many advantages such as high voltage, specific energy, and low environmental pollution. They have been widely used in the field of digital products, and are gradually expanding to the fields of electric vehicles, satellites, and aerospace. High energy and high density are the development direction of lithium-ion power batteries in the future. As an important material that affects the performance of lithium-ion power batteries, the research and development of positive electrode precursors has become the focus of the industry. [0003] Lithium-ion power batteries have high requireme...

AI Technical Summary

Problems solved by technology

The industrialized preparation of nickel-cobalt-aluminum ternary positive electrode materials adopts solid-phase doping of aluminum elements. Generally, nickel-cobalt or nickel-cobalt-manganese hydroxides are prepared first, and then the precursors are mixed with lithium salts and small-particle aluminum compounds. High-temperature treatment is difficult to achieve homogenization

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