Electrolyte additive, electrolyte and sodium metal battery

Abstract

In order to improve the oxidation resistance of an electrolyte, improve the overall coulombic efficiency of a battery, effectively inhibit the growth of sodium dendrites, improve the cycle stability of the battery and prolong the service life of the battery, the invention provides an electrolyte additive which comprises a benzene ring. The benzene ring has a first substituent group and a second substituent group; the first substituent group is fluorine; and the second substituent group is siloxane. Meanwhile, the invention also discloses an electrolyte containing the electrolyte additive and a sodium metal battery. According to the electrolyte provided by the invention, the oxidation resistance of the electrolyte is greatly improved, side reactions caused by oxygenolysis of the electrolyte in the discharge process are reduced, meanwhile, a negative electrode solid electrolyte membrane (SEI) and a positive electrode electrolyte interface membrane (CEI) of a sodium metal battery are optimized, the coulombic efficiency of the whole battery is improved, the growth of sodium dendrites is effectively inhibited, and the overall performance of the battery is improved.

Description

technical field [0001] The invention relates to the field of electrochemistry, more specifically, to an electrolyte solution additive, an electrolyte solution and a sodium metal battery. Background technique [0002] Rechargeable lithium-ion batteries (LIBs) have been widely used in small portable devices such as mobile phones and laptops due to their high energy density, long service life, wide operating temperature, and environmental friendliness. With the rapid development of the global electric vehicle market, traditional lithium batteries have been unable to meet the long-mileage battery life. Moreover, the shortage of lithium resources has led to a rapid rise in the price of lithium metal, and thus the cost of lithium-ion batteries has also risen sharply. Therefore, it is imperative to develop next-generation alkali metal batteries. Due to the abundant Na metal resources, Na-ion batteries (SIBs) are considered to be one of the most promising alternatives to Li-ion ba...

AI Technical Summary

Problems solved by technology

[0005] Among them, FEC as an electrolyte additive has a positive impact on the full battery, but the polarization potential of the sodium metal negative electrode is large, and a small amount of gas is continuously released, which may be harmful to battery performance in the long run.

And Na 2 S 6 Electrolyte additives in the form of KTFSI and KTFSI are only suitable for ether-based electrolytes, which have poor oxidation stability and are not suitable for high-voltage positive electrodes

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