Binder materials for the cathodes applied to self-stratifying membraneless microbial fuel cell

Area of Science:

• Electrochemistry
• Environmental Engineering
• Materials Science

Background:

• Self-stratifying membraneless microbial fuel cells (SSM-MFCs) are emerging technologies for sustainable urine treatment.
• Initial SSM-MFC prototypes utilized activated carbon (AC) and polytetrafluoroethylene (PTFE) for cathode construction.

Purpose of the Study:

• To investigate the efficacy of alternative cathode binders, specifically polyvinyl-alcohol (PVA) and PlastiDip (CPD), in SSM-MFCs.
• To evaluate sintered activated carbon (SAC) as a binderless cathode material for SSM-MFCs.
• To compare the performance, cost, and environmental impact of different cathode materials in SSM-MFCs for urine treatment.

Main Methods:

• Fabrication of SSM-MFC cathodes using AC with PTFE, PVA, or CPD binders.
• Testing of binderless SAC cathodes in SSM-MFC configurations.
• Performance evaluation of SSM-MFCs based on power output (μW, W·m⁻³, mW·m⁻²).
• Comparative analysis considering cathode material cost and environmental factors.

Main Results:

• SSM-MFCs with PTFE cathodes achieved the highest power output (1617 μW).
• SSM-MFCs using PVA and CPD binders exhibited comparable power outputs (1226 ± 90 μW), approximately 24% lower than PTFE.
• Binderless SAC cathodes demonstrated the lowest power output (≈1070 μW) but offered cost advantages.

Conclusions:

• PTFE currently provides the optimal binder for AC-based cathodes in SSM-MFCs.
• PVA presents a cost-effective and environmentally favorable alternative to PTFE, despite slightly lower power generation.
• SAC and PVA-based cathodes represent promising avenues for further development and optimization in SSM-MFC technology.