Preparation method of sodium-nitrogen in-situ doped ternary material

Abstract

The invention discloses a preparation method of a sodium-nitrogen in-situ doped ternary material, which comprises the following steps: uniformly mixing a lithium source, a sodium source and a ternaryprecursor Ni,1-a-b>CoMn (OH)<2> weighed according to a molar ratio, sintering at 700-900 DEG C in an oxygen-enriched atmosphere containing a nitrogen source, and naturally cooling to obtain the sodium-nitrogen in-situ doped ternary material Li<1-y>Na<y> (Ni<1-a-b>CoMn) N<x>O<2-X>, wherein x is larger than 0 and smaller than 0.1, y is larger than 0 and smaller than 0.1, 1-a-b is larger than 0.5 and smaller than 1, a is larger than 0 and smaller than or equal to 0.2, and b is larger than 0 and smaller than or equal to 0.2. The sodium-nitrogen in-situ doped ternary material prepared by theinvention not only is simple in preparation process, but also can effectively improve the capacity, the cycle performance and the rate capability of the ternary material.

Description

technical field [0001] The invention relates to the field of lithium batteries, in particular to a method for preparing a sodium-nitrogen in-situ doped ternary material. Background technique [0002] Today, with the rapid development of modern industry, the rapid development of economy brings about huge consumption of energy. In order to comply with the current development trend of low-carbon and environmental protection, people are trying their best to save energy and reduce emissions, and at the same time, they have also shifted their attention to a new generation of green power energy. [0003] In 1991, Sony Corporation proposed the first commercial lithium-ion battery with lithium cobalt oxide as the positive electrode and graphite as the negative electrode, realizing the commercialization of lithium-ion batteries in the true sense. Since then, lithium-ion batteries have developed rapidly. In 1995, polymer lithium-ion batteries came into being. In 1999, lithium-ion ba...

AI Technical Summary

Problems solved by technology

Such as 1) The low tap density of ternary materials is not conducive to industrial processing

(2) As mentioned above, Li in the material + with you 2+ The radius is close, and cation mixing is easy to occur, which will cause irreversible capacity loss of the material and affect the cycle performance of the material; (3) LiCo x mn y Ni 1-x-y o 2 During the charge and discharge process of the material, the valence state of Co and Ni elements will change frequently, which will easily lead to the change of the unit cell volume and affect the stability of the crystal structure.

Ni 2+ On the one hand, the formation of the lithium intercalation in the material reduces, on the other hand, it is combined with Li + Ni with a similar radius 2+ It will cause oxygen ions to mix, resulting in a significant decrease in the mobility of lithium ions in the lithium layer, and ultimately resulting in a decrease in the capacity, cycle performance, and rate performance of high-nickel ternary materials.

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