Improvement of Baker's yeast-based fuel cell power output by electrodes and proton exchange membrane modification

The production of more efficient yeast-based fuel cells (YFCs) depends on a combination of effective proton exchange membranes, electron mediators and current collectors. The adhesion of organisms on electrode surface plays a key role in the electron transfer process optimizing the generated power density. In this work, it is reported the preparation of a new YFC prototype using membranes of polyvinyl alcohol/ phosphoric acid and anodes of carbon nanotubes/polyurethane. The high surface area for yeast adhesion and the strong interaction established between cells/carbon nanotubes favor the energy generation in fuel cell. To evaluate the influence of external mediators and the consumption of feed solution (glucose) on performance of YFC, the kinetics of current generation of resulting fuel cells was analyzed. Results reveal that increases in the impedance of electrodes on generated power can be minimized by periodical infusion of feed fuel, preserving 70% of maximum power, representing an important condition for prolonged activity of fuel cell.