Manganese-base carbon-coated nano lithium-rich oxide and preparation method as well as application thereof

Abstract

The invention belongs to the technical field of lithium batteries, and discloses a manganese-base carbon-coated nano lithium-rich oxide and a preparation method as well as an application thereof. The preparation method comprises the following steps: under a condition of stirring, dissolving PVP in DMF, then, adding lithium acetate dihydrate, manganous acetate tetrahydrate, nickel acetate tetrahydrate and cobaltous acetate tetrahydrate according to a molar ratio of 1.26:0.54:0.13:0.13, stirring and dissolving evenly to obtain a metal salt solution; then, heating up the metal salt solution to 60-120 DEG C to carry out constant temperature treatment for 10-24 hours, thereby obtaining a gel-like object; heating up the gel-like object in the air to 400-500 DEG C to carry out constant temperature treatment for 3-8 hours, cooling naturally, then taking out and performing tablet compressing, and sintering for 7-12 hours at the temperature of 800-1000 DEG C to obtain a product. According to the invention, the preparation method is simple, problems, such as hydrolysis and aggregation of transition metal ions, are avoided, and the obtained product has good electrochemical performance when being used as a lithium ion battery positive electrode material.

Description

technical field [0001] The invention belongs to the technical field of lithium battery materials, and in particular relates to a manganese-based carbon-encapsulated nano-lithium-rich oxide and a preparation method and application thereof. Background technique [0002] With the gradual depletion of global fossil energy, environmental pollution is increasing, global energy and environmental problems are extremely severe, and the contradiction between economic growth and resources and environment is becoming more and more prominent, which poses a huge challenge to the sustainable development of human society. We urgently need to find Renewable clean energy. Lithium-ion batteries are favored because of their advantages such as high energy density, long cycle life, and low environmental pollution. As the most critical material in current lithium-ion batteries, the development of cathode materials is also receiving the most attention. In recent years, manganese-based layered lith...

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Problems solved by technology

In recent years, manganese-based layered lithium-rich oxide xLi 2 MnO 3 ·(1~x)LiMO 2 (M=Ni, Co, Ni 1 / 2 mn 1 / 2 , Ni 1 / 3 mn 1 / 3 co 1 / 3 etc.) has attracted widespread attention, because the lithium intercalation capacity of this material in the range of 2-4.8V can be as high as 250mAh / g or more, and it is currently the cathode material with the highest capacity in the transition metal system, and it mainly contains abundant manganese. , low cost and good safety performance, but this kind of material has problems such as large initial capacity loss, poor rate performance and voltage drop.

In order to solve these problems, people have adopted many methods. Among them, coating carbon is a relatively common and effective method to improve the performance of materials, but the method is basically to coat carbon on the surface of the material after the material is prepared. This method is more complicated and Coating is difficult to achieve a uniform effect, so the preparation of uniformly coated carbon layered lithium-rich materials with a simple process is one of the key research directions to improve the performance of lithium-ion batteries

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