Controlling the occurrence of power overshoot by adapting microbial fuel cells to high anode potentials

Type
Article

Authors
Zhu, Xiuping
Tokash, Justin C.
Hong, Yiying
Logan, Bruce E.

KAUST Grant Number
KUS-I1-003-13

Date
2013-04

Abstract
Power density curves for microbial fuel cells (MFCs) often show power overshoot, resulting in inaccurate estimation of MFC performance at high current densities. The reasons for power overshoot are not well understood, but biofilm acclimation and development are known factors. In order to better explore the reasons for power overshoot, exoelectrogenic biofilms were developed at four different anode potentials (-0.46 V, -0.24 V, 0 V, and 0.50 V vs. Ag/AgCl), and then the properties of the biofilms were examined using polarization tests and cyclic voltammetry (CV). The maximum power density of the MFCs was 1200±100 mW/m2. Power overshoot was observed in MFCs incubated at -0.46 V, but not those acclimated atmore positive potentials, indicating that bacterial activitywas significantly influenced by the anode acclimation potential. CV results further indicated that power overshoot of MFCs incubated at the lowest anode potential was associatedwith a decreasing electroactivity of the anodic biofilm in the high potential region,which resulted from a lack of sufficient electron transfer components to shuttle electrons at rates needed for these more positive potentials. © 2012 Elsevier B.V.

Citation
Zhu X, Tokash JC, Hong Y, Logan BE (2013) Controlling the occurrence of power overshoot by adapting microbial fuel cells to high anode potentials. Bioelectrochemistry 90: 30–35. Available: http://dx.doi.org/10.1016/j.bioelechem.2012.10.004.

Acknowledgements
This research was supported by Award KUS-I1-003-13 from the King Abdullah University of Science and Technology (KAUST). We also thank Dr. Ivan Ivanov for his helpful discussions.

Publisher
Elsevier BV

Journal
Bioelectrochemistry

DOI
10.1016/j.bioelechem.2012.10.004

PubMed ID
23178374

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