ALKALI METAL SALT OF FLUOROSULFONYL IMIDE, AND PRODUCTION METHOD THEREFOR

摘要

Provided is an alkali metal salt of fluorosulfonyl imide, wherein the amount of a specific impurity and the water content in the alkali metal salt is reduced and the alkali metal salt exhibits excellent thermal resistance. Also provided is a method for producing the alkali metal salt of fluorosulfonyl imide, whereby it is possible to easily remove the solvent from the reaction solution. Specifically provided is an alkali metal salt of fluorosulfonyl imide which is represented by general formula (I), wherein the mass loss is 2% or less when retained at 100°C for 8 hours in an air current. The method for producing the alkali metal salt of fluorosulfonyl imide involves a step for concentrating a solution of an alkali metal salt solution of fluorosulfonyl imide while bubbling a gas through the reaction solution that includes the alkali metal salt of fluorosulfonyl imide and/or a step for concentrating the solution of an alkali metal salt solution of fluorosulfonyl imide by means of thin film distillation.