Parallel Connection and Sandwich Electrodes Lower the Internal Resistance in a Microbial Fuel Cell

Abstract

The aim of this work was to design and characterize a novel, multiface parallelepiped MFC in the perspective of decreasing the internal resistance (Rint) and increasing the volumetric power (Pv) output. The cell was fitted with a ‘sandwich’ cathode-membrane-anode assemblage in five of its faces, and possessed a ratio electrode surface area-to-volume ξ (csi) of 19 m⁻¹ . When the 5 faces of the MFC-P were connected in series, the Rint was 601 Ω with a voltage of 0.52 V. Characterization of the cell with the 5 faces connected in parallel gave a Rint of 62 Ω with a voltage of 0.5 V that corresponded to external resistance of 56 k Ω in the polarization procedure. This result was ascribed to both the changes in cell architecture and decrease of the inter-electrode distance as well as the parallel connection. The Pv of the new MFC-P achieved values of 62 and 570 mW/m³ for series and parallel connection, respectively. Molecular ecological techniques were used to analyze the bacterial diversity of biocatalyst used in new design MFC-P. They showed a low species richness and low-to-moderate evenness. The community consisted primarily of δ-Proteobacteria and Firmicutes, bacteria that are recognized to be capable of exocellular electron transfer.

Key findings

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Identifiers

DOI

10.14447/jnmes.v15i3.64

Journal

Journal of New Materials for Electrochemical Systems

Year

2012