Improvement of microbial fuel cell performance using novel kaolin earthenware membrane coated with a polybenzimidazole layer

Abstract

A proton exchange membrane (PEM) is one of the most critical and expensive components in a dual-chamber microbial fuel cell (MFC) that separates the anode and cathode chambers. The novel macroporous kaolin earthenware coated with polybenzimidazole (NKE-PBI) fabricated in this study could become an alternative to PEM membranes. Briefly, PBI powder was dissolved in dimethylacetamide. Thereafter, NKE was fabricated at different porosities (10%, 20%, and 30%) using different starch powder volumes, which acted as pore-forming agents. The NKE-PBI with 30 vol% starch powder content produced the highest power output of 2450 ± 25 mW m−2 (10.50 A m−2) and internal resistance of 71 ± 19 Ω under batch mode operation. The MFC–PEM reactor generated the lowest power output at the highest internal resistance of up to 1300 ± 15 mW m−2 (3.7 A m−2) and 313 ± 16 Ω, respectively. In this study, the nonselective porous NKE coated with PBI membranes improved proton conduction activity and displayed comparable power performance with that of Nafion 117 in a dual-chambered MFC. Therefore, a porous earthenware membrane coated with a proton conductor could become a potential separator in a scaled-up MFC system for commercialization.