Improving Microbial Fuel Cell Performance Using Porous Capacitive Composite Bioanode Materials with Energy Storage Function

Abstract

Microbial fuel cells (MFCs) have shown promise in solving energy and environmental problems, but their practical application is limited by their low power output. In this study, carbon nanotubes/polypyrrole composite anode materials were prepared on a porous sponge matrix. By combining the porous characteristics of sponge, the good conductive properties of carbon nanotubes, and the energy storage ability of polypyrrole capacitive materials, the prepared anode exhibited a large specific capacity, high porosity, large specific surface area, good electron transport ability, and good biocompatibility. The results showed that the maximum power density of the modified anode MFC reached 7.46 W m−3, which was 2.53 times higher than that of the control anode. The stored energy Qs released by the modified anode was 235.6 C m−2, 6.5 times higher than that of the control electrode. In addition, the transfer impedance Rct of the S/CNT/PPy electrode (5.5 Ω) was much lower than that of the control anode (16.8 Ω). The research presented in this paper demonstrates a new approach to improving the power generation ability and energy storage performance of MFCs.