High-Performance Fuel Cell Membrane Materials
Physical Sciences : Materials and Compounds
Available for licensing
- Arumugam Manthiram, Ph.D. , Mechanical Engineering
- Yongzhu Fu , Texas Materials Institute
State-of-the-art fuel cell membranes have many shortcomings. Nafion, one of the most widely available membranes, cannot operate in temperatures in excess of 100 degrees Celsius, and because it must be wet to allow proton conduction, the fuel cell requires a complex external humidification system. Further, when used in direct methanol fuel cells (DMFCs), these membranes exhibit high methanol crossover, reducing the efficiency and hindering performance. Because of this, the fuel cell must be highly loaded with platinum catalyst, an expensive component. These membranes are expensive and simply do not offer the efficient performance and low cost that is required for widespread adoption of fuel cell technology.
This invention is a new class of polymer blend membrane materials based on N-heterocycle pendant groups that offers significant improvements over the Nafion membrane. First, when used in hydrogen fuel cells, it can be used as a high-temperature membrane that can be operated in excess of 100 degrees Celsius and at a low relative humidity. Thus, the fuel cell humidification system can be eliminated or drastically simplified. Furthermore, higher temperatures reduces the poisoning of the platinum catalyst by carbon monoxide impurity, thereby reducing fuel overloading and cleanup, and offering significant cost reduction.
This membrane also makes drastic improvements in DMFCs by reducing the permeability to methanol. With less methanol crossover, there is reduced poisoning of the platinum catalyst, resulting in significantly better performance and lower cost.
- Better performance in both proton exchange and direct methanol fuel cells
- Reduces cost of fuel cleanup (to remove CO)
- Reduces cost of platinum catalyst
- Reduces cost of humidification system
- More efficient operation compared to Nafion
- Significantly cheaper than Nafion
- Long-term stability
- Useful in both Proton exchange and direct methanol fuel cells
- Operates at high temperatures (in excess of 100 degrees Celsius)
- Operates at low relative humidity
- Reduces catalyst poisoning and sensitivity to carbon monoxide
- Reduces methanol crossover/permeability
- Reduces or eliminates need for humidification system
The market for fuel cells currently stands at about $1 billion but is predicted to grow fifteen-fold by 2015. Considering the public’s interest in reducing energy costs and the federal government’s commitment to research and development of alternative energy technology, the outlook for fuel cells is strong. This technology may be a stepping stone to realizing the use of DMFCs in small portables like laptops and cell phones because of its drastic performance and cost improvements over the Nafion membrane. However, it will also be useful in the development of proton exchange fuel cells for stationary and trasportation applications.
- 1 U.S. patent issued: 8,288,025