Study on the performance of microbial fuel cells through electrochemical impedance spectroscopy method by Geobacter sulfurreducens as a biocatalyst

Abstract

Microbial Fuel Cells (MFCs) is emerging as a new source of renewable energy due it its ability to convert waste materials into electricity through the metabolic activity of the electrogenic bacteria in the fuel cell. The performance of two types of material as the anode for a dual-chambered mediatorless MFC using G. sulfurreducens was compared and observed. The electrochemical characteristics such as ohmic resistance, polarization resistance, total internal resistance and double layer capacitance were analyzed by using Electrochemical Impedance Spectrocospy (EIS) method. Nyquist Plot and Bode Plot were fitted to an Equivalent Circuit Model (ECM) to represent the behavior of the electrochemical system and validify the experimental data. The polarization resistance, which was the major contributor to the internal resistance in this study were determined to be 445.22ω and 204.7ω, with residual sum square, χ2 of 0.647 and 0.1857 for graphite plate and graphite felt respectively. It can be concluded that polarization resistance play an important role in determining the performance of MFCs with different anode.