Increased power generation in supercapacitive microbial fuel cell stack using Fe–N–C cathode catalyst

Santoro, Carlo; Kodali, Mounika; Shamoon, Najeeb; Serov, Alexey; Soavi, Francesca; Merino-Jimenez, Irene; Gajda, Iwona; Greenman, John; Ieropoulos, Ioannis; Atanassov, Plamen

Abstract

© 2018 The Authors The anode and cathode electrodes of a microbial fuel cell (MFC) stack, composed of 28 single MFCs, were used as the negative and positive electrodes, respectively of an internal self-charged supercapacitor. Particularly, carbon veil was used as the negative electrode and activated carbon with a Fe-based catalyst as the positive electrode. The red-ox reactions on the anode and cathode, self-charged these electrodes creating an internal electrochemical double layer capacitor. Galvanostatic discharges were performed at different current and time pulses. Supercapacitive-MFC (SC-MFC) was also tested at four different solution conductivities. SC-MFC had an equivalent series resistance (ESR) decreasing from 6.00 Ω to 3.42 Ω in four solutions with conductivity between 2.5 mScm−1 and 40 mScm−1. The ohmic resistance of the positive electrode corresponded to 75–80% of the overall ESR. The highest performance was achieved with a solution conductivity of 40 mS cm−1 and this was due to the positive electrode potential enhancement for the utilization of Fe-based catalysts. Maximum power was 36.9 mW (36.9 W m−3) that decreased with increasing pulse time. SC-MFC was subjected to 4520 cycles (8 days) with a pulse time of 5 s (ipulse 55 mA) and a self-recharging time of 150 s showing robust reproducibility.

• Journal Article Type: Article
• Acceptance Date: Nov 1, 2018
• Online Publication Date: Nov 30, 2018
• Publication Date: Feb 1, 2019
• Deposit Date: Jan 16, 2019
• Publicly Available Date: Jan 16, 2019
• Journal: Journal of Power Sources
• Print ISSN: 0378-7753
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 412
• Pages: 416-424
• DOI: https://doi.org/10.1016/j.jpowsour.2018.11.069
• Keywords: supercapacitor, microbial fuel cell, galvanostatic discharges, Fe-based catalyst, long terms stability
• Public URL: https://uwe-repository.worktribe.com/output/852701
• Publisher URL: https://doi.org/10.1016/j.jpowsour.2018.11.069
• Contract Date: Jan 16, 2019