SYNTHESIS AND CHARACTERIZATION OF A SERIES OF FLUORINE-SUBSTITUTED PHENYLENE-THIENYL POLYMERS FOR BATTERY APPLICATIONS

A series of fluorine-substituted phenylene-thienyl-based monomers ( 1, 4-bis(2-thienyl)-benzene (THB), 1,4-bis(2-thienyl) -2-fluorophenylene (TFP), 1,4-bis(2-thienyl)-2,5-difluorophenylene (TF2P), and 1,4-bis(2- thienyl)-2,3,5,6-tetrafluorophenylene (TF4P)) has been synthesized. Th in films of the polymers were deposited by controlled electropolymeriz ation of the monomers, and the doping densities and cycling efficienci es were determined from electrochemical measurements. The polymers pol y-1,4-bis( 2-thienyl)-benzene (pTHB),poly-1,4-bis( 2-thienyl) -2-fluor ophenylene (pTFP), and poly-1,4-bis( 2-thienyl) -2,5-difluorophenylene (pTF2P) exhibited reversible p-doping and n-doping, with doping densi ties in the range 0.12 to 0.45 electrons per monomer unit. The cycling efficiencies were higher for p-doping than for n-doping, with values in the range of 99.58 to 99.70% charge retained per cycle. (C) 1998 El sevier Science S.A. All rights reserved.