Sandwich type composite positive electrode material of lithium battery, preparation method thereof, and lithium battery positive electrode

Abstract

The invention provides a sandwich type composite positive electrode material of a lithium battery. The sandwich type composite positive electrode material comprises positive electrode material particles, the positive electrode material particles form a central core, three coating layers are located at the outside of the central core, which are sequentially an inner aluminum oxide layer, a zinc oxide layer and an outer aluminum oxide layer from inside to outside, and the diameter of the central core is 10nm to 10microns. A metal oxide is deposited on carbon powder with a high specific surface area by using an atomic layer deposition method, and the mass ratio of the thin metal oxide to carbon with high specific surface area is 70-90%. The invention further provides a method for preparing the carbon with high specific surface area / metal oxide composite positive electrode material by using the atomic layer deposition method, and a method for preparing an electrode by using the carbon withhigh specific surface area / metal oxide composite positive electrode material. The carbon with high specific surface area / metal oxide composite positive electrode material provided by the invention has the characteristics of high mass ratio, and the lithium ion battery prepared by the electrode material has a high cycle life and high capacity stability.

Description

Technical field [0001] The invention relates to the technical field of new lithium battery materials, in particular to a lithium battery sandwich composite anode material and a preparation method thereof, and a lithium battery anode. Background technique [0002] Driven by the demand for increased energy density in consumer electronics, electric vehicles and even power grids, modern lithium-ion batteries are usually designed to operate in a wide electrochemical window to achieve maximum energy density. Although exceeding the limit of the cut-off potential can enable the battery to provide higher energy density while increasing the specific capacity and higher output voltage, it also makes the battery face greater challenges in thermodynamic and kinetic stability. Especially for layered lithium transition metal oxides, using a wider electrochemical window, although the capacity can be increased, but the stability is reduced. In the field of materials research, due to the instabil...

AI Technical Summary

Problems solved by technology

In recent years, atomic layer deposition technology has been widely used in the surface coating of lithium-ion battery cathode materials, which can protect the cathode materials well at the nanometer scale. However, the atomic layer coating technology reported before is mostly limited to the deposition of alumina using general formulas. Al 2 o 3 and other materials

The compactness of atomic layer deposition requires that the coating material has ideal conductivity and lithium conductivity, otherwise it will completely block the migration of electrons and ions, so although the stability of the positive electrode material is significantly improved, the capacity will be significantly reduced

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