Self-stacked submersible microbial fuel cell (SSMFC) for improved remote power generation from lake sediments

Electric energy can be harvested from aquatic sediments by utilizing microbialfuelcells (MFCs). A main challenge of this application is the limited voltage output. In this study, an innovative self-stackedsubmersible MFC (SSMFC) was developed to improve the voltage generation from lakesediments. The SSMFC successfully produced a maximum power density of 294 mW/m2 and had an open circuit voltage (OCV) of 1.12 V.

However, voltage reversal was observed in one cell at high current density. Investigation on the cause for voltage reversal revealed that voltage reversal was occurring only when low external resistance (≤400 Ω in this study) was applied. In addition, the internal resistance and OCV were the most important parameters for predicting which cell unit had the highest probability to undergo voltage reversal.

Use of a capacitor was found to be an effective way to prevent voltage reversal and at the same time store power. These results provide new insight into the development of effective MFC system, capable of extracting energy and promoting bioremediation of organic pollutants from sediments.