Voltage increase of microbial fuel cells with multiple membrane electrode assemblies by in series connection

A multiple membrane electrode assembly installed microbial fuel cell (mMEA-MFC) was operated to harvest bioelectricity from organic materials. In the mMEA-MFC reactor, four MEAs were installed and shared electrolyte solution. Each MEA displayed 0.68 ± 0.02 V in open-circuit voltage (OCV) and 0.34 ± 0.01 V in closed-circuit voltage (CCV) at 1 kΩ of external resistance. The MEAs in each of the three mMEA-MFC reactors were serially connected, and improved voltages were observed shortly after the series connection (2.06 ± 0.03 V as OCV and 0.73 ± 0.01 V as CCV, respectively). The OCV was increased ideally to the sum of OCV from the unit cells, while voltage losses were generated in series connection in the CCV mode. Even though the voltage losses were generated in CCV, the series connection between each MEA belongs to individually operated reactor increased the output voltage of mMEA-MFCs which sharing an electrolyte solution.

► We constructed multiple membrane electrode assembly microbial fuel cell (mMEA-MFC).
► The mMEA-MFCs were operated in series connection mode and current interruption mode.
► The voltage output increased by serially connecting mMEA-MFCs.
► Competition of electrolyte was observed and evidenced in current interruption mode.
► Competition phenomenon was caused by proton concentration and increased conductivity.