Performance study of μDMFC with foamed metal cathode current collector

Area of Science:

• Materials Science
• Electrochemistry
• Energy Conversion

Background:

• Micro Direct Methanol Fuel Cells (μDMFCs) are promising for portable power due to their eco-friendly and compact nature.
• The longevity and efficiency of μDMFCs depend critically on the corrosion resistance and performance of their cathode current collectors.
• Variable operating conditions necessitate current collectors that maintain stability during redox reactions.

Purpose of the Study:

• To investigate the impact of different cathode current collector materials and structures on μDMFC performance.
• To compare the efficiency of foam stainless steel (FSS) and foam titanium (FT) collectors in both hole-type and grid-type configurations.
• To identify the optimal cathode current collector for enhanced μDMFC operation.

Main Methods:

• Preparation of four cathode current collectors: hole-type FSS, grid-type FSS, hole-type FT, and grid-type FT.
• Performance evaluation using I-V-P polarization curves, Electrochemical Impedance Spectroscopy (EIS), and discharge tests.
• Testing μDMFCs in a 1 mol L⁻¹ methanol solution at 70 °C.

Main Results:

• The hole-type FSS cathode current collector μDMFC (HFSS-μDMFC) achieved a maximum power density of 49.53 mW cm⁻², a 70.15% improvement over the hole-type FT counterpart (HFT-μDMFC).
• The grid-type FSS cathode current collector μDMFC (GFSS-μDMFC) showed a maximum power density of 22.60 mW cm⁻², outperforming the grid-type FT version (GFT-μDMFC) by 11.99%.
• Optimal μDMFC performance was observed with the HFSS-μDMFC in a 1 mol L⁻¹ methanol solution.

Conclusions:

• Foam stainless steel (FSS) demonstrates superior performance as a cathode current collector for μDMFCs compared to foam titanium (FT).
• The hole-type structure for FSS collectors provides significantly better power density and efficiency.
• The HFSS-μDMFC configuration is identified as the most effective for achieving high performance in μDMFC applications, particularly in 1 mol L⁻¹ methanol solutions.