Imagine a power plant in your home. The idea is not so far-fetched – if fuel cells can be scaled up to produce that amount of power.
Solid oxide fuel cells (SOFCs), which convert a fuel’s chemical energy to electrical energy, are one of the most promising technologies for generating and distributing electricity more efficiently. Companies like Google, Walmart and FedEx are piloting their use in stores on a limited basis.
Steve McIntosh, assistant professor of chemical engineering, wants to make SOFCs even more commercially viable. He is seeking to maximize the flow of electrical current through fuel cells by minimizing the voltage needed to drive reactions, and move ions, within the cell.
To produce energy as efficiently as possible, McIntosh and his group are studying advanced functional materials. Their goal is to design a cell that can run on any fuel – something no one has yet achieved.
“Fuel cells operate by transporting oxygen anions from the air side of the cell to the fuel side,” says McIntosh. “Catalysts facilitate the key reactions at both sides of the cell. If you can reduce the cell’s resistance to this process, you can drive more current, and thus generate more power, from a single cell.
“We want to understand the fundamental barriers to these reactions in order to develop more active materials and structures.”
In one NSF project, McIntosh is trying to run fuel cells with natural gas instead of hydrogen. Currently fuel cells must break down hydrocarbons such as natural gas into carbon monoxide and hydrogen before they can be utilized to generate electrical power. The key to further commercialization, McIntosh says, is designing a cell that will react with any fuel.
In addition to the catalytic components, McIntosh is also seeking to transport ions easily across fuel cells, batteries and other solid-state ion conductors. In pursuit of this goal, McIntosh is working with Oak Ridge National Laboratory and its accelerator- based neutron source. He and his colleagues are studying the structure and properties of crystals under fuel cell operating conditions to find the optimal design for ion transport.
“We’ve had success in operating these fuel-flexible cells at the laboratory scale,” he says. “What we want to do is scale up the performance to a level that would allow commercial manufacture.
“If that can be achieved, fuel cells could revolutionize the generation and distribution of electrical power.”