METHOD FOR PREPARING LITHIUM BIS (FLUOROSULFONYL) IMIDE

A method for preparing lithium bis(fluorosulfonyl)imide. The method comprises the steps of: 1) preparing lithium fluorosulfonamide; 2) preparing sulfuryl fluoride, introducing the sulfuryl fluoride into a lithium fluorosulfonamide solution, and adding an acid binding agent, to prepare a bis(fluorosulfonyl)imide ammonium salt; 3) dissolving the bis(fluorosulfonyl)imide ammonium salt in an aqueous solution, and obtaining an aqueous solution of bis(fluorosulfonyl)imide by acidic resin exchange; 4) adding lithium carbonate to adjust the pH value to neutral, removing insoluble matter by filtration, removing most of the water under reduced pressure, adding a weakly polar organic solvent to precipitate a crude product of lithium bis(fluorosulfonyl)imide, and further drying the crude product under reduced pressure; and 5) adding a polar solvent to the crude product of lithium bis(fluorosulfonyl)imide, stirring the solution to dissolve the crude product, removing insoluble matter by filtration, removing the strongly p