Continuous flow membrane-less air cathode microbial fuel cell with spunbonded olefin diffusion layer

Area of Science:

• Electrochemistry
• Biotechnology
• Materials Science

Background:

• Microbial fuel cells (MFCs) offer sustainable energy production.
• Membrane-less MFCs simplify design and reduce costs.
• Controlling oxygen diffusion and water loss at the air cathode is crucial for performance.

Purpose of the Study:

• To evaluate the long-term power production performance of a membrane-less air-cathode MFC.
• To assess the efficacy of a spunbonded olefin sheet as an alternative to PTFE coating for cathode performance.
• To identify factors contributing to power output decline over time.

Main Methods:

• Constructed a membrane-less MFC with anode, cathode, and micro-fiber cloth separator.
• Applied a spunbonded olefin sheet to the air-facing cathode side to manage oxygen and water.
• Monitored power production, cathode potential, and coulombic efficiency for 53 days.

Main Results:

• Achieved a low cell resistance of approximately 4Ω and a peak power density of 750 mW/m².
• Observed a decrease in maximum power density to 280 mW/m² over 53 days.
• Attributed power decline to platinum catalyst loss (8.26%) and cathode biomass growth (38.44%).
• Demonstrated effective water management and no leakage with the spunbonded olefin sheet.

Conclusions:

• The spunbonded olefin sheet is a viable, cost-effective alternative to PTFE for air-cathode MFCs.
• Long-term MFC performance is significantly impacted by catalyst degradation and biomass accumulation.
• Further research should focus on mitigating catalyst loss and biomass growth for sustained power output.