Lithium-enriched manganese-based material precursor as well as preparation method, lithium-enriched manganese-based anode material and preparation method thereof, lithium battery

Abstract

The invention relates to a lithium-enriched manganese-based material precursor which is a lithium-enriched manganese-based carbonate precursor of a lamellar morphology, the particle size of the precursor is 1-7mu m, and the specific surface area of the precursor is 8-50m<2> / g. By adopting the lithium-enriched manganese-based carbonate precursor of the lamellar morphology, a lithium-enriched manganese-based anode material of a high single crystallization degree can be easily prepared. The invention further relates to a preparation method of the lithium-enriched manganese-based carbonate precursor of the lamellar morphology, and a preparation method and the application of the lithium-enriched manganese-based anode material of a single crystal morphology. Therefore, the mechanical strength, the stability, the compaction density, the capacity and the first efficiency of the micro structure of the anode material can be improved, and the voltage attenuation of the material can be inhibited.

Description

technical field [0001] The invention relates to the technical field of lithium battery materials, in particular to a lithium-rich manganese-based material precursor, its preparation method and application. Background technique [0002] In recent years, the field of use of lithium-ion batteries has been continuously expanding. From traditional 3C products to current electric vehicles and smart grids, the demand for lithium-ion batteries, especially high-energy-density lithium batteries, in the new energy industry is becoming more and more urgent. To meet this demand, a great deal of research effort has been devoted to finding and developing electrode materials with high specific capacity. Lithium-rich manganese-based cathode material aLi 2 MnO 3 ·(1-a)LiMO 2 [0<a<1, M=one or more of Ni, Co, Mn, Al, V, Cr, Fe] The discharge specific capacity exceeds 250mAh / g, and the working voltage is greater than 3.50V, because of its high specific capacity , good thermal stability...

AI Technical Summary

Problems solved by technology

The single crystal lithium-rich manganese-based positive electrode material prepared by this method can indeed improve the electrochemical performance of the material. However, an oxygen-enriched (higher oxygen concentration than air) atmosphere is required during the preparation process, and the calcination temperature is as high as 950-1200°C. The production cost is high, and the precursor needs to be pulverized and ball milled before calcination. The process is more complicated, and more importantly, the hardness of the carbonate precursor is low, and it is easy to be excessively pulverized to form fine slag during pulverization and ball milling. This kind of fine slag is not only small and irregular, but it is difficult to remove in actual production, and it will also leave a great safety hazard for the use of positive electrode materials.

Also, see figure 1 The SEM image of the single crystal lithium-rich manganese-based multi-component material prepared for this prior art, it is not difficult to see that the degree of single crystallization of the material prepared by this method is not high, and the electron microscope topography image obviously contains many fine particles <1 μm. These fine particles will also have many side reactions with the electrolyte, and there is a cohesive structure in the upper left corner of the figure (referred to as a single crystal in the industry), and the particle size is very uneven. Problems will affect and lead to the attenuation of battery performance

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