Composite carbon cathode material for lithium ion battery and preparation method thereof

Abstract

The invention discloses a composite carbon cathode material for a lithium ion battery and a preparation method thereof, and relates to a cathode material for a lithium ion battery. The invention provides the composite carbon cathode material for the lithium ion battery and the preparation method thereof, wherein the composite carbon cathode material can reduce the influence of a solid electrolyte interface (SEI) film on the cyclical stability of the cathode material, partially prevent anode dissolved metal ions from being deposited on the surface of the cathode material to affect the cyclical performance of the cathode material and still provide high specific energy under the condition of high charging current. The composite carbon cathode material is provided with a nuclear shell layer structure of at least three layers, wherein the outer layer is a metal layer, an alloy layer or a carbon layer; the middle layer is a lithiated metal oxide layer or a metal oxide layer; and the inner layer is a carbon material layer. The preparation method comprises the following steps of: mixing and then drying a raw material for preparing a metal oxide and a carbon material; heating and sintering the dried raw materials under the protection of atmosphere to obtain a composite material of the lithiated metal oxide or metal oxide layer with nuclear shell structure and the carbon material; and plating a metal, alloy or carbon conductive layer with reversible mechanical ductility on the surface of the composite material to obtain a product.

Description

technical field [0001] The invention relates to a negative electrode material of a lithium ion battery, in particular to a composite carbon negative electrode material for a lithium ion battery and a preparation method thereof. Background technique [0002] Lithium-ion batteries have the characteristics of high voltage, high specific energy, long life, no memory effect, and small self-discharge. They have been widely used in various portable electronic products, and have potential application markets in fields such as hybrid electric vehicles and pure electric vehicles. . At present, commercial lithium-ion batteries generally use graphite-based carbon materials as negative electrode materials. Although they have the characteristics of high material specific capacity and relatively high lithium intercalation potential, the fast charging performance of lithium-ion batteries based on carbon-based negative electrode materials is poor. It has affected a large number of applicati...

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Problems solved by technology

[0003] The purpose of the present invention is to address the shortcomings of the existing carbon negative electrode materials that have poor high-rate charging performance, and provide a method that can reduce the impact of the SEI film on the cycle stability of the negative electrode material through a reasonable structural design, and can also partially avoid the dissolution of the positive electrode. Effect of metal ions on the cycle performance of the negative electrode material after deposition on the surface, which can still provide high specific energy composite carbon negative electrode material for lithium ion batteries under the condition of large charging current and its preparation method

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