A novel microbial fuel cell electrode design: prototyping a self-standing one-step bacteria-encapsulating bioanode with electrospinning

In this study, the electrospinning technique is shown to be a viable method for the synthesis of a bacteria-encapsulating bioanode. A coaxial setup was designed to yield in one step a bioanode made of two fibers networks: one encapsulating the electroactive bacteria Shewanella oneidensis and the other one providing the necessary conductivity for electron transport throughout the bioelectrode. The electrical conductivity of this integrated bioanode (similar to 10(-2) to 10(-3) S cm(-1)) was deemed satisfactory and it was then included into a microbial fuel cells (MFC). The resulting MFC exhibited electricity generation. We further demonstrate that this electrode can be cryodesiccated and still exhibits an electrochemical activity once integrated into the MFC reactor. Its volume current and power densities were similar to those recorded for the fresh electrospun bioanode (up to 3260 A m(-3) and 230 W m(-3) for the thin cryodesiccated bioanode (similar to 410 mu m)). Such impressive volume current densities for thin electrospun systems may be for instance envisioned to be applied to wearable or paper-based MFCs which require a certain flexibility.

Automated summary

The study demonstrates that electrospinning technique can be used to synthesize a bacteria-encapsulating bioanode with satisfactory electrical conductivity. The bioanode shows electrochemical activity even after cryodesiccation and can be integrated into microbial fuel cells, exhibiting impressive volume current densities. This thin electrospun system may have potential applications in flexible MFCs or paper-based MFCs.