High-Efficiency Energy Converters
Hydration-Free Proton Conductive Membranes Based on Two Dimensional Materials
Fuel cell vehicles offer a low-emissions alternative to petroleum-fueled vehicles, but hydrogen fuel cell vehicle deployment has been limited because of high costs and limited refueling infrastructure. A new proton conducting membrane is an enabling ingredient for numerous technologies, such as electrolyzers, flow batteries, and fuel cells, all of which could benefit from a non-hydrated proton exchange membrane (PEM). In PEM fuel cells, the membrane accounts for 20 to 50% of the cost (depending on the production volume), with the humidity control system adding to the overall complexity and cost. A highly selective, non-hydrated PEM could enable the use of affordable and abundant methanol or other alcohols as a fuel, which have historically been limited by crossover through the membrane. By removing system-level humidity control requirements, the reduced system complexity would lower the overall cost, which could enable greater deployment of fuel cells for transportation applications.
The team led by Oak Ridge National Laboratory will design proton-selective membranes for use in storage technologies, such as flow batteries, fuel cells, or electrolyzers for liquid-fuel storage. Current proton-selective membranes (e.g. Nafion) require hydration, but the proposed materials would be the first low-temperature membranes that conduct protons without the need for hydration. The enabling technology relies on making single-layer membranes from graphene or similar materials and supporting them for mechanical stability. The team estimates that these membranes can be manufactured at costs around one order of magnitude lower than Nafion membranes. Due to the lower system complexity, the team's innovations would enable fuel cell production at lower system-level costs.
If successful this technology could substantially lower the cost of fuel cells, and encourage greater adoption of fuel cells in transportation and stationary applications.
Enabling efficient fuel cells to run on hydrogen or alcohols would diversify the resources we rely on for transportation.
Fuel cells are more efficient energy-conversion technologies than internal combustion engines and do not emit harmful air pollutants.
Domestic production of low-cost PEMs and low-cost fuel cells could enable widespread deployment of fuel cells for transportation, stationary, and portable applications.
