Manindra Kumar

Microbial fuel cell (MFC), a biochemical‐catalyzed system which generates electricity by oxidizing biodegradable organic matter in the presence of either fermentative bacteria or enzymes, is a growing technology for electricity generation. It is a dual functioning technology which not only generates electricity but also treats wastewater, thereby addressing two major problems of the present world. As the technology is an emerging one, there are numerous challenges to be confronted. One of the vital components of the MFC is the proton exchange membrane (PEM), and it is due to the high cost of this membrane that MFC technology is still running at laboratory scale. In the present study, a starch‐based electrolyte film is used as PEM. Electrochemical behavior exhibited by the starch electrolyte is studied and on using it as PEM in MFC it is found to exhibit power density of ≈16 mW m⁻² and the current density of ≈85 mA m⁻². One of the main advantages of the material is its cost which is approximately INR ≈940 per square foot compared to INR 70 000 per square foot of Nafion (the most popular membrane).

Biodegradable polymer electrolyte systems are the most sought over option for cheap and energy efficient storage devices. Present paper discusses the results of potato starch + MgCl ₂ system which satisfy the technical and economic criteria to become a potential candidate for future electrolyte systems. The developed system has high ionic conductivity (~3.43 × 10 ^-2 S/cm), low relaxation time (75 μs) and wide electrochemical stability window (ESW ~4.6 V). The phase angle approaches -79° and maintains its value for 10 Hz to 1 kHz frequency range. The prepared material is a free standing film which can be bended and twisted up to 90°, which makes it suitable for flexible electrochemical device fabrication. The equivalent series resistance (ESR) is quite low (3.41 Ω) and self-resonance frequency below which energy can be efficiently stored is approximately 0.1 MHz. Hence the present study reports an economical, easy to handle and environment friendly electrolyte suitable for electrochemical device fabrication.