Performance enhancement of microbial fuel cell by applying transient-state regulation

A binder-free, pseudocapacitive anode was fabricated by coating reduced graphene oxide (rGO) and manganese oxide (MnO2) nanoparticles on stainless steel fibre felt (SS). Microbial fuel cell (MFC) equipped with this novel anode yielded a maximum power density of 1045 mW m(-2), 20 times higher than that of a similar MFC with a bare SS anode (46 mW m-2). Transient-state regulation (TSR) was implemented to further improve the MFC's power generation. The optimal TSR duty cycle ranged from 67% to 95%, and the MFC's power density increased with TSR frequency. A maximum power density output of 1238 mW m-(2) was achieved at the TSR duty cycle of 75% and the frequency of 1 Hz, 18.4% greater than that obtained from the steady state operation. The TSR mode delivered better MFC performance especially when the external resistance was small. Long-term operation tests revealed that the current density and power density yielded in the TSR mode were on average 15.0% and 32.7% greater than those in the steady state mode, respectively. The TSR mode was believed to reduce the internal resistance of the MFC while enhance substrate mass transfer and electron transfer within the anode matrix, thereby improving the MFC performance. (C) 2016 Elsevier Ltd. All rights reserved.