Power generation using adjustable Nafion/PTFE mixed binders in air-cathode microbial fuel cells.

Nafion, poly(tetrafluoroethylene) (PTFE) and polymers made of Nafion-PTFE mixture (Nafion and PTFE ratios of 1:2 and 2:1) were examined as catalyst binders in air-cathode microbial fuel cells (MFCs). MFC tests showed that the maximum power density (from 549 to 1060 mW/m2) increased with the increase of Nafion percentage in binders (from 0% to 100%). Multi-cycle tests (25 cycles) showed that the maximum voltages decreased by 4-6% with simultaneous increase in Coulombic efficiency in all MFCs using various binders (from 20% to 29% with Nafion binder; from 17% to 26% with other binders), indicating that adjustable Nafion/PTFE mixed polymers were applicable in MFCs as catalyst binders when considering both cost and performance of cathodes.