Air-breathing cathode self-powered supercapacitive microbial fuel cell with human urine as electrolyte

Abstract

In this work, a membraneless microbial fuel cell (MFC) with an empty volume of 1.5 mL, fed continuously with hydrolysed urine, was tested in supercapacitive mode (SC-MFC). In order to enhance the power output, a double strategy was used: i) a double cathode was added leading to a decrease in the equivalent series resistance (ESR); ii) the apparent capacitance was boosted up by adding capacitive features on the anode electrode. Galvanostatic (GLV) discharges were performed at different discharge currents. The results showed that both strategies were successful obtaining a maximum power output of 1.59 ± 0.01 mW (1.06 ± 0.01 mW mL −1 ) at pulse time of 0.01 s and 0.57 ± 0.01 mW (0.38 ± 0.01 mW mL −1 ) at pulse time of 2 s. The highest energy delivered at i pulse equal to 2 mA was 3.3 ± 0.1 mJ. The best performing SC-MFCs were then connected in series and parallel and tested through GLV discharges. As the power output was similar, the connection in parallel allowed to roughly doubling the current produced. Durability tests over ≈5.6 days showed certain stability despite a light overall decrease.

The Use of Electroactive Halophilic Bacteria for Improvements and Advancements in Environmental High Saline Biosensing

“…In addition to the study presented above, several microbial fuel cells in high saline environments have been developed for the treatment of wastewater and power production from urine [ 42 , 44 , 45 , 59 , 60 , 61 , 62 , 63 ]. Recently reviewed, microbial fuel cells in high saline have demonstrated great potential for the monitoring and sensing of the degradation of organics in high saline water [ 43 , 46 ].…”