关键词: 微生物阳极燃料电池, 极性反转, 阳极极化

Abstract: Voltage reversal behavior was investigated in microbial-anode fuel cells (MFCs). Electricity-producing biofilms were developed on the surface of anodes in MFCs inoculated with mixed inoculum from activated sludge. MFC duplicates generally exhibited different performances with respect to the internal resistance, the voltage output and the discharging duration when operating in batch mode. Voltage reversal was observed to occur first in the MFC with lower performance when connecting MFCs in series. Analysis of electrode potentials indicated that the potentials of microbial anodes quickly shifted to more positive values when enhancing discharge current, resulting in voltage reversal in MFCs. Increasing temperature would enhance the limiting current at room temperature, and avoiding the voltage reversal. Fuel shortage would enable the voltage reversal to easily occur. However, high discharge current still generates voltage reversal in fuel-rich MFCs. The performance of microbial anodes was observed to be affected with the voltage reversal. Transient voltage reversal had no obvious effect on the performance of the microbial anode. However, the performance of microbial anodes would decrease with increasing duration of voltage reversal. Microbial anodes were observed to be destroyed, and the performance of the microbial-anode fuel cells would not be recovered after long-time voltage reversal.

Key words: microbial- anode fuel cells, voltage reversal, anodic polarization