Poly(3,4-alkylenedioxythiophene)-based supercapacitors using ionic liquids as supporting electrolytes

A series of dual conducting polymer based type I supercapacitors were constructed using poly(3,4-propylenedioxythiophene) and poly(3,4-ethylenedioxythiophene) as electrode couples. The switching speeds and cycle lifetimes of these supercapacitors were compared using two types of supporting electrolytes; lithium bis(trifluoromethanesulfonyl)imide and 1-ethyl-3-methyl-1-H-imidazolium bis(trifluoromethanesulfonyl)imide (a room temperature molten salt). The results indicate that supercapacitors using 1-ethyl-3-methyl-1-H-imidazolium bis(trifluoromethanesulfonyl)imide as the supporting electrolyte have cycle lifetimes superior to supercapacitors using lithium bis(trifluoromethanesulfonyl)imide as the supporting electrolyte. (C) 2002 The Electrochemical Society.