A kind of preparation method of multi-component cathode material with multi-level structure

Abstract

The invention relates to a preparation method of a multi-element anode material with a multi-level structure. The multi-element anode material comprises a core layer, a middle layer and an outer layer, wherein the anode material has the following chemical formula (1-a-b) LiNi<l-x-y>CoxAlyO2.aLiNi0.2Co0.4Mn0.4O2.bLiCo0.3Mn0.2Al0.5O2, wherein the a is equal to 0.2-0.3, the b is 0.1-0.15, the x is 0.1-0.15, and the y is 0.15-0.2. The method comprises the following steps of (1) preparing a presoma of the core layer; (2) forming a presoma with the middle layer through a coprecipitation method; (3) forming a presoma with the outer layer through a penetration method; and (4) sintering. The multi-element anode material prepared by the invention has a three-level layer structure with different component matching ratios. The proportion of the core layer is high, the core layer has the high Ni content, the high capacity of a material is guaranteed, the middle layer has the high cobalt content, the cycling stability of the material is guaranteed, the outer layer has the high aluminum content, and the thermal stability of the material is improved.

Description

Technical field [0001] The invention relates to a preparation method of a multi-component positive electrode material with a multi-level structure. Background technique [0002] Lithium-ion batteries have been widely used in mobile phones, notebook computers, digital cameras and other electronic products, and are developing into large-scale power batteries (such as for electric vehicles) and energy storage batteries (such as for solar and wind power generation systems). [0003] Currently commercialized positive electrode materials mainly include lithium cobalt oxide (LiCoO 2 ), lithium nickelate (LiNiO 2 ), lithium manganate (LiMnO 2 ) and nickel-cobalt-manganese ternary materials, spinel-structured lithium manganate (LiMn 2 o 4 ), lithium vanadium phosphate (Li 3 V 2 (PO 4 ) 3 ) and polyanionic cathode material lithium metal phosphate (LiMPO 4 ) and lithium metal silicate (Li 2 MSiO 4 ). Layered lithium cobalt oxide cathode material is the earliest commercializ...

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Problems solved by technology

[0004] As a high specific capacity and high specific energy density material, high-nickel multi-component materials have been widely studied all over the world. However, even if high-nickel multi-component materials are doped with other elements, at about 220 ° C, the material in the charged state Surface Ni 4+ and Co 4+ And NiO and electrolyte, release a lot of heat and oxygen, which reduces the cycle performance of the material and affects its safety performance, affecting the commercial application of the material