Performance evaluation of microbial fuel cells: effect of varying electrode configuration and presence of a membrane electrode assembly

Membrane electrode assembly (MEA), a common arrangement used in direct methanol fuel cells, has been employed in a fed-batch mode microbial fuel cell (MFC), using mixed microbial population. This modification has been done for analyzing the prospect of obtaining increased power productivity. In addition, the electrodes have also been configured for the purpose of better current collection. Use of MEA as a replacement of the conventionally used 'separate membrane and electrode' arrangement has evidently resulted in reducing one of the limiting factors for higher power production in MFC, that is, its internal resistance. Open circuit potentials of more than 1 volt have been obtained for two MFC setups: (a) one consisting of an MEA and (b) the other having electrodes situated 2 cm apart from each other, but having better current collectors than the first setup. Power densities of 2212.57 mW m(-2) and 1098.29 mW m(-2) have been obtained at corresponding current densities of 5028.57 mA m(-2) and 3542.86 mA m(-2), respectively. The potential and power obtained for the MFC consisting of an MEA is quite significant compared to the other systems employed in this study.