Spinel-coated layered positive electrode material and preparation method and application thereof

Abstract

The invention discloses a spinel-coated layered positive electrode material with a heterostructure and a preparation method thereof, a positive electrode of a lithium-ion battery of using the positiveelectrode material and the lithium-ion battery of using the positive electrode. According to the spinel-coated layered positive electrode material, a precursor is prepared by using an existing coprecipitation preparation technology, and the precursor is subjected to surface oxidation treatment through an extremely simple mixing method and then subjected to high-temperature heat treatment, therebyobtaining a heterogeneous positive electrode material of employing a lithium-rich layered material as a core and a spinel material as a protective shell. The modification method is easy to operate, high in security, low in cost and suitable for large-scale production; the obtained spinel coating layer is relatively high in integrity and uniformity and adjustable in thickness; the spinel-coated layered positive electrode material is much higher than a commercial positive electrode material in rate capability and cycling stability; and the demand for the lithium-ion battery with high energy density, a long cycle and high stability in the market can be met.

Description

technical field [0001] The invention belongs to the field of lithium ion battery materials, and in particular relates to a preparation method of a spinel-coated layered positive electrode material, a modified layered positive electrode material prepared by the method, and a lithium ion battery containing the material. Background technique: [0002] In response to the crisis brought about by the dwindling reserves of fossil energy and the intensification of environmental pollution, the development of renewable energy has become an important basis for the sustainable development of human society. The development and utilization of these energy sources must involve energy storage and conversion, which promotes the emergence and development of chemical power sources. Due to the advantages of high voltage, high energy density, small self-discharge, long cycle life, no pollution and no memory effect, lithium-ion batteries have been widely used in computers, communications and cons...

AI Technical Summary

Problems solved by technology

There are three-dimensional lithium ion transport channels in the spinel structure, and the heat release is low, which is conducive to improving the cycle performance and safety of the material, and the oxygen ions in the structure and the layered structure of the lithium-rich cathode material are all hexagonal close-packed, which is It provides a structural possibility for the composite production of the two, but most of the existing technical means are to prepare layered spinel blended composite materials by changing the calcination process, which cannot exert the surface protection of the spinel phase. Most of them are layered / spinel blended composite materials formed by adjusting the amount of lithium source or sintering temperature, rather than building a coating layer. A small part of the work is to form a spinel coating by precipitation, but the precipitation The process is not deposited uniformly, resulting in poor continuity of the coating formed

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