Microbial Fuel Cells (MFCs) are bio-electrochemical devices that use the power of respiring microbes to convert organic matter into electrical energy. Thus, they can help treat wastewater and also generate electricity. Realising the vast potential these cells have, scientists are finding ways to improve their performance and efficiency. In one such effort, scientists from the Indian Institute of Technology Bombay (IITB) have demonstrated how stainless steel wool, coated with conducting polymers, could be used in microbial fuel cells to improve their performance.
Microbial fuel cells work by the action of microorganisms, which digest organic matter. In the presence of oxygen, this process produces carbon dioxide and water. However, in the absence of oxygen, as seen in sewage treatment plants and industrial effluent discharge, the process produces carbon dioxide, electrons and protons. Electricity is produced when these electrons are captured using electrodes. Hence, one way to improve the performance of the fuel cells is to use a better material for electrodes.
In this study, researchers have demonstrated, for the first time, the use of low-cost stainless steel wool as an efficient material for one of the electrodes (anode) used in fuel cells. They found that using stainless steel wool resulted in a 70% increase in power density (the amount of power per unit volume), as compared to stainless steel tubes, when used as an anode. Further, they observed that steel wool, when coated with conductive polymers like polyaniline and polypyrrole, performed twice as better than plain steel wool.
With more suitable materials and efficient design, MFCs could be our solution to waste management with energy generation in the future.