New polymeric cathode binders for microbial fuel cells

A microbial fuel cell (MFC) utilizes a bacteria-laden anode to liberate electrons from organic compounds. Electricity-generating bacteria reside abundantly in domestic wastewater, ocean sediments, animal wastes, etc., making MFC technology a renewable energy technology. In addition to the bacterial anode, the cathode plays a crucial role in MFC performance because of poor kinetics of oxygen reduction and the expensive materials typically used in cathode construction. Polymeric cathode binders with a range of ion contents were examined here for their performance in single chamber air-cathode MFCs. The cathode binder polymers are based on sulfonated poly(phenylsulfone) and therefore much less expensive than Nafion, the standard material used in MFC cathodes. Sulfonated poly(phenylsulfone) binders showed better or equivalent performance to standard Nafion-based cathodes. It is hypothesized that tuning the ion-content of the cathode binder polymer to match the ionic concentration in the MFC buffer can help increase the performance of MFC cathodes.