Characterization of a microbial fuel cell with reticulated carbon foam electrodes

[Display omitted] ► Reticulated vitreous carbon is tested as electrode material in a microbial fuel cell. ► Good stability and robustness of the biofilm to feeding risks are found. ► The power density is 40W/m3, limited by cathode overpotentials. ► Impedance spectrometry reveals the complex nature of the phenomena. ► Oxygen diffusion at the cathode is modeled by a Warburg element. A microbial fuel cell with open-pore reticulated vitreous carbon electrodes is studied to assess the suitability of this material in a batch mode, in the perspective of flow-through reactors for wastewater treatment with electricity generation. The cell shows good stability and fair robustness in regards to substrate cycles. A power density of 40W/m3 is reached. The cell efficiency is mainly limited by cathodic transfers, representing 85% of the global overpotential in open circuit. Through impedance spectrocopy, equivalent circuit modeling reveals the complex nature of the bioelectrochemical phenomena. The global electrical behavior of the cell seems to result in the addition of three anodic and two cathodic distinct phenomena. On the cathode side, the Warburg element in the model is related to the diffusion of oxygen. Warburg resistance and time are respectively 2.99kΩcm2 and 16.4s, similar to those published elsewhere.