title: Elimination of Power Overshoot at Bioanode through Assistance Current in Microbial Fuel Cells.
abstract: The power overshoot generated by electron depletion in microbial fuel cells (MFCs) was characterized in this study. Various causes of power overshoot, identified in previous studies, are discussed in terms of their plausible contributions to electron depletion. We found that power overshoot occurred if the anodic overpotential generated by electron depletion exceeded the cathodic overpotential. The introduction of assistance current from anode connections, which ameliorated the electron depletion in the MFCs, immediately eliminated the power overshoot. As a result, if the electron production at the anode exceeded electron reduction at the cathode, a power overshoot was not generated. The results revealed that introducing assistance current supplied from an additional anode to the limited anode eliminated power overshoot. The power overshoot is not generated by kinetic limitation at the cathode; it is only generated by the kinetic limitation at the anode. The mechanism underlying power overshoot should be considered in the design of MFCs to improve reliability, particularly in scaled-up plant applications. The proposed technique is more practical than previously proposed methods.
authors.affiliation: School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Korea.
authors.forename: Bongkyu
authors.initials: B
authors.lastname: Kim
authors.affiliation: School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Korea.
authors.forename: Junyeong
authors.initials: J
authors.lastname: An
authors.affiliation: School of Earth Sciences and Environmental Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Korea.
authors.forename: In Seop
authors.initials: IS
authors.lastname: Chang
mesh_terms: D001674:Bioelectric Energy Sources; D004553:Electric Conductivity; D004566:Electrodes; D004579:Electron Transport; D004867:Equipment Design
keywords: assistance current; bioanode; electron depletion; microbial fuel cells; power overshoot