(528e) Electrolyte Development and Selection for Membrane Electrode Assemblies In Alkaline Fuel Cells

Alkaline fuel cell (AFC) operation is currently limited to specialty applications such as low temperatures and pure H₂/O₂ due to the corrosive nature of the electrolyte and formation of carbonates.  This work will develop new electrolytes that are less corrosive, have higher operating temperatures, and enable alternative fuels.   AFCs are the cheapest and potentially most efficient (approaching 70%) fuel cell.  The fact that non-Pt catalysts can be used, makes them an ideal low cost alternative for power production.  Power is produced by electrochemically combining a H₂ rich fuel (H₂ or methanol) with O₂ to produce H₂O and power.  The anode and cathode are separated by and solid electrolyte or alkaline porous media saturated with KOH.  However, CO₂ from the atmosphere or fuel feed severely poisons the electrolyte by forming insoluble carbonates. Corrosivity of the KOH (electrolyte) also limits operating temperatures to no more than 80°C.  This work will focus on the examination of ionic liquids as electrolyte solutions for the replacement of KOH.  Highly conductive ionic liquids (IL) are chosen as alternative electrolytes to KOH as they do not chemically bond to CO₂.  Low corrosivity and negligible vapor pressures of the IL will allow the operation at high temperatures.  This approach is novel as it targets the root of the problem (the electrolyte) unlike other current work in alkaline fuel cells which focus on making the fuel cell components more durable.