Evaluation of electrode and solution area-based resistances enables quantitative comparisons of factors impacting microbial fuel cell performance

Rossi, Ruggero; Cario, Benjamin P.; Santoro, Carlo; Yang, Wulin; Saikaly, Pascal E.; Logan, Bruce E.

Abstract

Direct comparisons of microbial fuel cells based on maximum power densities are hindered by different reactor and electrode sizes, solution conductivities, and materials. We propose an alternative method here, the electrode potential slope (EPS) analysis, to enable quantitative comparisons based on anode
and cathode area-based resistances and operating potentials. Using EPS analysis, the brush anode resistance (RAn = 10.6 ± 0.5 mΩ m2) was shown to be 28% lower than the resistance of a 70% porosity diffusion layer (70% DL) cathode (RCat = 14.8 ± 0.9 mΩ m2) and 24% lower than the solution resistance (RΩ = 14 mΩ m2) (acetate in a 50 mM phosphate buffer solution). Using a less porous cathode (30% DL) did not impact the cathode resistance but did reduce the cathode performance due to a lower operating potential. With low conductivity domestic wastewater (RΩ = 87 mΩ m2), both electrodes had higher resistances [RAn = 75 ± 9 mΩ m2, and RCat = 54 ± 7 mΩ m2 (70% DL)]. Our analysis of the literature using EPS analysis shows how electrode resistances can easily be quantified to compare system performance when the electrode distances are changed or the sizes of the electrodes are different.

• Journal Article Type: Article
• Acceptance Date: Feb 27, 2019
• Online Publication Date: Feb 27, 2019
• Publication Date: Apr 2, 2019
• Deposit Date: Apr 17, 2019
• Publicly Available Date: Apr 17, 2019
• Journal: Environmental Science and Technology
• Print ISSN: 0013-936X
• Electronic ISSN: 1520-5851
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 53
• Issue: 7
• Pages: 3977-3986
• DOI: https://doi.org/10.1021/acs.est.8b06004
• Public URL: https://uwe-repository.worktribe.com/output/851722
• Publisher URL: http://dx.doi.org/10.1021/acs.est.8b06004
• Additional Information: Additional Information : This is an open access article published under an ACS Author Choice License (https://pubs.acs.org/page/policy/authorchoice_termsofuse.html)
• Contract Date: Apr 17, 2019