In this paper three air and water-stable room temperature ionic liquids(RTILs): N-butylpyridinium tetrafluoroborate(BPBF 4), 1-butyl-3-methylimidazolium tetrafluoroborate(BMIBF 4), and 1-ethyl-3-methylimidazolium ethyl sulfate(EMISE) were synthesized. Their electrochemical windows were measured by cyclic voltammetry at 303.15-343.15 K. The cyclic voltammograms show the order of windows which represent the electrochemical stability of RTIL is: BPBF 4BMI+--0.95 V->BP+-0.02 V-. It is very interesting that while the oxidative limit of anion BF- 4 and the reductive limit of all the cations reduce with the increase of temperature, but the oxidative limit of anion SE- increases.
