METHOD (2) FOR PREPARING BIS(FLUOROSULFONYL)IMIDE LITHIUM SALT (LIFSI) HAVING REDUCED FLUORINE ANION AMOUNT

The present invention provides a method for preparing a bis(fluorosulfonyl) imide lithium salt, comprising the steps of (a) manufacturing ammonium bis(fluorosulfonyl)imide by reacting bis(chlorosulfonyl)imide with NH4F(HF)n (n = 0-10) and (b) reacting the ammonium bis(fluorosulfonyl)imide with a lithium base, wherein in step(s) (a) and/or (b), a process of removing fluorine anions by adding tetraalkyl orthosilicate to a reaction solution is carried out, after the reaction. La présente invention concerne une méthode de préparation d'un sel de lithium bis(fluorosulfonyl)imide, comprenant les étapes consistant à (a) fabriquer du bis(fluorosulfonyl)imide d'ammonium par réaction de bis(chlorosulfonyl)imide avec du NH4F(HF)n (n = 0-10) et (b) faire réagir le bis(fluorosulfonyl)imide d'ammonium avec une base de lithium, dans les étapes (a) et/ou (b), un procédé d'élimination d'anions fluor par ajout d'orthosilicate de tétraalkyle à une solution de réaction étant effectué, après la réaction. 본 발명은 (a) 비스(클로로술포닐)이미드를 NH4F(HF)n(n=0~10)와 반응시켜서 암모늄 비스(플루오르술포닐)이미드를 제조하는 단계; (b) 상기 암모늄 비스(플루오르술포닐)이미드를 리튬 염기와 반응시키는 단계;를 포함하며, 상기 (a)단계 및 (b)단계 중의 어느 한 단계 이상에서, 반응 후 반응용액에 테트라알킬오소실리케이트(Tetra alkyl orthosilicate)를 첨가하여 불소음이온을 제거하는 공정을 수행하는 것을 특징으로 하는 비스(플루오르술포닐)이미드 리튬염의 제조방법을 제공한다.