EXAMPLE - Trifluoro oxy chloride (CF3OCl) (in g) (24) was introduced to a vacuum stainless steel tube and sulfur dioxide (14) was introduced. Then the resulting mixture was reacted with cooling at -196degreesC to -20degreesC for 8 hours and trifluoro methyl oxy sulfonyl chloride (CF3OSO2Cl) (15.5) was obtained. Trifluoro methane sulfonamide (30.2) dissolved in dehydration methanol (200 ml) was added to tert-butoxy potassium (23.3) and the resulting mixture was reacted at 60degreesC for 3 hours. The solution was concentrated under reduced pressure and white powder was obtained. Dehydration diethyl ether (250 ml) was added to the powder and set as slurry. The slurry was cooled to 0degreesC. The obtained trifluoro methyl oxy sulfonyl chloride (15.5) and dehydration diethyl ether liquid mixture (100 ml) were mixed and the obtained solution was reacted at room temperature for 4 hours after 2 hours stirring at 0degreesC. Subsequently, the obtained slurry was cooled, filtered, washed with diethyl ether and crystal was removed. The crystal was dried under reduced pressure and (trifluoromethyl sulfuric acid (trifluoromethyl sulfonic acid) imide-potassium salt (54.3) with a yield of 81% was obtained. The obtained powder (6.7) and 5-azonia-spiro(4,4)nonane-iodide (5.1) were mixed in a glove box under nitrogen atmosphere and 10% or less relative humidity. Anion exchange water (500 ml) was added to the resulting mixture and two-layer separation was performed. Methylene chloride (100 ml) was added and extracted. The organic layer was washed twice with ion exchange water (50 ml). The obtained organic layer was concentrated without pressure application and yellow transparent liquid of trifluoromethyl sulfuric acid (trifluoromethyl sulfonic acid) imide-5-azonia-spiro (4,4) nonane salt) (7.9) was obtained. The obtained nonane salt had melting point of 12.6degreesC and ionic conductivity of 7.1 mS/cm at 25degreesC. Reduction was not received in the potential of more than 0.3 (V vs Li+/Li).