Electrolyte salts for rechargeable magnesium-ion batteries
摘要
說明書
A salt of Formula (I), namely Mg(THF)7[Al(OC(CF3)3)4]2, was prepared and the electrochemical properties thereof were evaluated. Reaction of lithium aluminum hydride with perfluoro-tert-butanol (“PFTB”; about 4 equiv.) formed a lithium salt of formula LiAl(OC(CF3)3)4. The lithium salt was then reacted with hydrochloric acid in a nonaqueous solvent an containing diethyl ether to afford a compound of formula H(Et2O)2[Al(OC(CF3)3)4]2 (“H(Et2O)2[AlPFTB4]2”) with lithium chloride as a byproduct. The H(Et2O)2[AlPFTB4]2 was then reacted with magnesium bis(hexamethyldisilazide) (“Mg(HMDS)2”) in Et2O/THF solvent to afford a salt of formula Mg(THF)7[Al(OC(CF3)3)4]2 (also referred to herein as Mg(THF)7[AlPFTB4]2, or simply “Mg(AlPFTB4)2” when referring to the salt without regard to the presence or absence of ether solvation). As described elsewhere herein, Mg(AlPFTB4)2 is soluble in THF, and is thermally stable below about 240° C. Mg(AlPFTB4)2 also is electrochemically stable when cycled with a magnesium electrode, and is surprisingly oxidatively stable up to about 5.4 V versus Mg, which is a significant improvement over state of the art magnesium electrolyte materials.
