Modified lithium nickel manganese oxygen material, preparation method of modified lithium nickel manganese oxygen material, and lithium ion battery

Abstract

The invention discloses a modified lithium nickel manganese oxygen material, a preparation method of the modified lithium nickel manganese oxygen material, and a lithium ion battery. The molecular formula of the modified lithium nickel manganese oxygen material is LiNi(0.5-x / 2)MxMn(1.5-x / 2)O(4-y)Fy, wherein x is greater than or equal to 0.004 and is less than or equal to 0.2, y is greater than or equal to 0.002 and is less than or equal to 0.1, and M is one of Co, Al, Cr, Zr, Fe and Ti. The existence of the Mn<3+> ions is eliminated effectively by co-doping of anions and cations, the generation of a Jahn-Teller effect can be inhibited, and the average valence of Mn can be increased; the electronegativity of fluorine is greater than that of oxygen, and the capability of attracting electrons is high; the fluorine is doped, so that the structure of the LiNi0.43Ti0.14Mn1.43O3.95F0.05 material is relatively stable, and the reversibility is enhanced when the LiNi0.43Ti0.14Mn1.43O3.95F0.05 material is used as an electrode material; the interfacial characterization between the electrode material and electrolyte is improved; the dissolving and the erosion of the electrolyte to the material is relieved in the charge and discharge processes.

Description

technical field [0001] The invention belongs to the technical field of lithium ion batteries, and in particular relates to a modified lithium nickel manganese oxide material, a preparation method thereof, and a lithium ion battery. Background technique [0002] With the depletion of fossil fuels, new energy technology is recognized as a high-tech today, and the battery industry, as an important part of the new energy field, has become a hot spot in global economic development. Among them, lithium-ion batteries have been widely used due to their high energy density, high voltage platform, long service life, small self-discharge, no memory effect, wide operating temperature range, and no pollution to the environment. As far as the composition of lithium-ion batteries is concerned, it is mainly composed of positive electrodes, negative electrodes, separators, electrolytes, casings and other components. Among them, the positive and negative electrode materials are active materia...

AI Technical Summary

Problems solved by technology

[0003] However, currently LiNi 0.5 mn 1.5 o 4 The cycle performance and rate performance of the material are not satisfactory, and Mn is often produced during the preparation process. 3+ , Li x Ni 1-x o 2 It is difficult to prepare products with stoichiometric ratio, and these impurities will cause poor cycle performance during battery cycling.

And LiNi 0.5 mn 1.5 o 4 The high voltage during charging and discharging causes the electrolyte on the electrode surface to be oxidized and decomposed, which limits its commercial application

In order to solve this problem, many scholars have modified it by doping, but LiNi 0.5 mn 1.5 o 4 The performance of the material changes less, and there are problems such as inaccurate control of the doping amount, and the performance of the prepared material is not good.

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