Aggrandizing power output from Shewanella oneidensis MR-1 microbial fuel cells using calcium chloride

► Current output from microbial fuel cells using S. oneidensis MR-1 can be increased using μM quantities of calcium chloride. ► Increase in output current not correlated with increased in conductivity or decreased in internal MFC resistance. ► Mild aggregation evident suggesting primary cause of the increase in current output. ► Non-linear correlation between short circuit current output and calcium chloride concentration demonstrated.