Increased performance of a tubular microbial fuel cell with a rotating carbon-brush anode

A novel method was proposed to improve the power output of microbial fuel cells (MFCs) by rotating the carbon-brush anode. The MFC with a rotating anode produced a peak power density of 210±3 W/m3 and a maximum current density of 945±43 A/m3, 1.4 and 2.7 times higher than those of the non-rotating case, respectively. The difference of the electrochemical impedance spectroscopy and cyclic voltammetry before and after anode rotation clearly suggested that the mass transfer to the spiral space was enhanced by the rotating anode. Furthermore, Tafel plots analysis also revealed that the rotating anode can improve the electrochemical activity of the biofilm.