Preparation method of nanometer lithium lanthanum titanate coated 0.5Li2MnO3 0.5LiNi0.5Mn0.5O2 material

Abstract

The invention provides a preparation method of a nanometer lithium lanthanum titanate coated 0.5Li2MnO3 0.5LiNi0.5Mn0.5O2 material. Compared with the prior art, the method has the advantages that the lithium lanthanum titanate is a very good lithium conductor, is applicable to fast migration of lithium ions, and achieves the effect of improving the material rate capability; meanwhile, due to the surface coating, the protection effect is achieved on the body material; the contact between the material and electrolyte can be reduced; the occurrence of side reaction can be reduced; the manganese ion dissolution separation due to corrosion of HF on the material per se is reduced; the coulombic efficiency and the circulation stability are improved. By controlling the preparation process parameters, the 0.5Li2MnO3 0.5LiNi0.5Mn0.5O2 material with good performance is obtained through preparation; then, the material is subjected to uniform nanometer lithium lanthanum titanate surface coating, so that the first-time coulombic efficiency, the rate capability and the circulation stability are improved.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and relates to the modification research of lithium-ion battery cathode materials, in particular to 0.5Li coated with nano-lanthanum lithium titanate 2 MnO 3 0.5LiNi 0.5 mn 0.5 o 2 The method of preparation of the material. Background technique [0002] Lithium-ion battery positive electrode materials with application prospects in the field of electric vehicles mainly include lithium iron phosphate and lithium manganate. Although lithium iron phosphate with an olivine structure has low cost and good rate performance, its industrialization level and application prospects are limited due to its low energy density (generally less than 120Wh / Kg), poor processing consistency, and poor low-temperature performance. ; In addition, lithium manganate with a spinel structure has the advantages of a three-dimensional deintercalation channel structure that is very suitable for lithium ions ...

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Problems solved by technology

[0004] However, people have also found in the research that although LNMO has a high discharge specific capacity and energy density, it also has problems such as low initial Coulombic efficiency, poor rate performance, and capacity fading. Therefore, it is necessary to modify the surface of this type of material. To meet the requirements of electric vehicles for high rate, high energy density and long life of lithium-ion batteries

[0005] In order to overcome the problems of poor rate performance and capacity fading in the application of lithium-rich manganese-rich solid solution battery materials, the current solution to the above problems in the industry is mainly through material body doping or / and surface coating, while the surface The type of coating material is closely related to the performance of the battery material

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