Abstract: Disclosed is a production method of a lithium tetrafluoroborate solution for use as a lithium battery electrolytic solution, including: a reaction step of forming lithium tetrafluoroborate by reaction of lithium fluoride and boron trifluoride in a chain carbonate ester solvent and thereby obtaining a reaction solution of the lithium tetrafluoroborate dissolved in the chain carbonate ester solvent; a water removal step of adding a water removing agent to the reaction solution; an acidic impurity removal step of removing an acidic impurity component from the reaction solution by concentrating the reaction solution after the water removal step; and a dilution step of diluting the concentrated solution after the acidic impurity removal step. It is possible by this method to obtain the lithium tetrafluoroborate solution whose acidic impurity content and water content are reduced to be 50 mass ppm or lower and 15 mass ppm or lower, respectively.

Abstract: To provide an imide salt represented by the formula wherein, R represents a halosulfonyl group (—SO2X1 where X1 is a halogen such as fluorine, chlorine, bromine and iodine) or dihalophosphoryl group (—POX2X3 where X2 and X3 are the same or different halogens such as fluorine, chlorine, bromine and iodine), and M represents an alkali metal; with high selectivity and high efficiency by using a low-cost starting material. In the production of an imide salt, an alkali metal fluoride, a sulfuryl halide or phosphoryl halide, and ammonia or an ammonium salt are reacted. According to this method, a desired imide salt can be produced with high yield, while greatly suppressing the production of a by-product.

Abstract: Disclosed is a method for producing “a salt or a complex comprising imide and an organic base”, characterized by reacting halogenated sulfuryl or halogenated phosphoryl with ammonia in the presence of an organic base. According to this method, a target imide compound can be produced in a high yield while significantly suppressing the production of by-products. Further, by reacting the obtained imide compound with an alkali metal hydroxide or an alkaline earth metal hydroxide, an imide metal salt can be easily derived.