METHOD FOR PRODUCING LITHIUM FLUOROSULFONATE, LITHIUM FLUOROSULFONATE, NONAQUEOUS ELECTROLYTIC SOLUTION, AND NONAQUEOUS ELECTROLYTIC SOLUTION SECONDARY BATTERY

The present invention relates to a method for producing lithium fluorosulfonate which comprises reacting a lithium salt and fluorosulfonic acid in a nonaqueous solvent, wherein the lithium salt is a lithium salt not generating water through the reaction step.