A series of dual conducting polymer based type I supercapacitors were constructed using poly͑3,4-propylenedioxythiophene͒ and poly͑3,4-ethylenedioxythiophene͒ as electrode couples. The switching speeds and cycle lifetimes of these supercapacitors were compared using two types of supporting electrolytes; lithium bis͑trifluoromethanesulfonyl͒imide and 1-ethyl-3-methyl-1-Himidazolium bis͑trifluoromethanesulfonyl͒imide ͑a room temperature molten salt͒. The results indicate that supercapacitors using 1-ethyl-3-methyl-1-H-imidazolium bis͑trifluoromethanesulfonyl͒imide as the supporting electrolyte have cycle lifetimes superior to supercapacitors using lithium bis͑trifluoromethanesulfonyl͒imide as the supporting electrolyte.