Critical parameters selection in polarization behavior analysis of microbial fuel cells

Polarization behavior analyses of two mirobial fuel cells equipped with non-capacitive and capacitive anodes, respectively, were conducted by using linear sweep voltammetry (LSV) and varying circuit resistance (VCR) methods at various parameters. The LSV took short time, but the measured maximum power density (Pmax) varied greatly when the parameters like open circuit time (toc), scan rate (rscan) and scanning direction were not chosen properly. It suggested that relatively accurate Pmax could be obtained by scanning the MFCs from 0 V to open circuit potential with toc of about 0.5 h and rscan below 0.5 mV s−1. On the contrary, the VCR took relatively longer time but the measured Pmax was more stable and accurate once the time duration was in a suitable range, e.g. 0.25-2 h, regardless of the anode type; moreover, the effects caused by the measuring direction and toc were not obvious.