Nafion 1135 vs SDAPP3(3.5 mil)

• High conductivity (tunable, conductivity equivalent to Nafion®)
  
• Lower fuel crossover
  
• Enhanced hydrogen fuel cell performance
  40% power increase @ 80°C and 100% RH
  Enhanced performance and elevated temperature operation means…
  Increased CO resistance, heat rejection, water management (smaller stack)
  
• Improved methanol fuel cell performance
  25% power increase @ 80°C and 100% RH
  Low methanol crossover means…
  Higher density fuel storage, longer operation life, greater fuel efficiency

Targeted Research Opportunities for Improved Fuel Cell Performance

First Generation Sandia PEM

Assess performance and optimize materials for use at lower relative humidity.
Problem: Current proton exchange membranes, including Nafion®, do not have high proton conductivity at low water contents.

Solution: New materials with organized structures, water retention capabilities, and nanophases that conduct protons and replace water.

Assess and increase fuel cell lifetime of new materials at high temperatures.
Problem: Nafion® “thins” at high temperatures (>80°C) leading to membrane perforation, hot spots, and fuel cell failure.

Solution: High-strength proton exchange membranes (PEMs) and nanocomposite PEMs that are resistant to mechanical and thermochemical degradation under harsh fuel cell environments.

Reduce interfacial resistance between membrane and electrodes.
Problem: Current Nafion® electrodes are not compatible with new membranes, causing large interfacial resistance losses and poor device performance.

Solution: Develop replacement electrolytes that are compatible with alternative PEM materials that possesses high transport properties, high electrode performance, and compatible with current electrode deposition techniques.

Sandia strengths:

• Polymer science and synthesis
• Hybrid organic-inorganic materials
• Microfabrication, nanophase catalysts• Catalysis
• •Microelectromechanical systems
• Separations
• Engineering
• Modeling

Enhanced fuel cell material performance via nanomaterials and molecular engineering of PEMs

Goals via high-temperature membrane:

• Decrease water management system via low RH
• Decrease on-board water storage
• Fuel cell operation: 120°C and 50% RH
• Improved performance via lower interfacial resistance
• Enhanced conductivity at low RH

Contact: Chris Cornelius
cjcorne@sandia.gov
(505) 844-3497