NaFSI electrolyte powder

Sodium bis(fluorosulfonyl)imide, abbreviated NaFSI, is a white, crystalline salt. It is hygroscopic and deliquescent and usually stored under inert atmosphere. NaFSI is soluble in water, carbonates (including dimethyl carbonate, diethyl carbonate, and propylene carbonate), glymes (including monoglyme, diglyme, and triglyme), dimethoxyethane, trimethyl phosphate, and bis(fluorosulfonyl)imide-based ionic liquids such as N-methyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide ([C3mpyr]+FSI-) or N-butyl-N-methylpyrrolidinium ([C4mpyr]+FSI-). NaFSI melts at 109 °C.

NaFSI is commonly used as an electrolytic salt in sodium-ion batteries because of its high solubility and high ionic conductivity in solution. Our battery grade NaFSI with low moisture, acid, and high purity is tailored to sodium-ion battery applications. NaFSI is compatible with a host of cathode materials including Na₂Ti₃O₇ , Na₃V₂(PO₄)₃ , and anode materials such as hard carbon and sodium metal. Recently, scientists have found that high-concentration and localized high-concentration electrolytes using NaFSI outperform traditional dilute electrolytes, enabling dramatically improved cycling stability. , These localized high-concentration electrolytes typically involve 1.5 M NaFSI in a carbonate or ether solvent that is diluted with a fluoroether. Another recent report showed that electrolytes composed of high-concentration NaFSI in ionic liquids form favorable solid electrolyte interphase and enable stable cycling with sodium metal anodes for over 700 cycles.