Portable Membrane-Less Soil Microbial Fuel Cell: Using Multiwalled CNT Paper Electrodes.

Soil microbial fuel cells (SMFCs) are attractive for low-cost bioelectricity generation. In this study, a multiwalled carbon nanotube paper (MCNTP) was fabricated by a simple method for use as the anode and cathode electrodes in a stab-type membrane-less SMFC (SSMFC). Activated carbon powder, carbon fibers, and cellulose fibers were bound by multiwalled carbon nanotube paint to form the MCNTP. As a result, the MCNTP exhibited high conductivity, flexibility, and durability. In addition, the SSMFC was designed as a module mounted with three anodes in series and a floating air cathode. The SSMFC could be activated on demand by simply stabbing in the wet soil. Experimental results showed that the floating cathode outperformed the non-floating one. The SSMFC generated the output shortly after being plugged into the wet soil. The maximum power density was at the level of 60–70 mW/m² for three separate experiment cycles. Additionally, a single SSMFC was used to power a clock as an example to demonstrate its practical use. [ABSTRACT FROM AUTHOR]