WVU Engineers Use Cutting-Edge Technology to Mitigate Corrosion Problems

Postdoctoral researcher Lingfeng Zhou. Photo courtesy of West Virginia University/Nathaniel Godwin.

Recently published research by engineers from West Virginia University (Morgantown, West Virginia, USA) marks a big step forward in improving the durability and performance of the solid fuel cells that power plants can use to generate electricity. Postdoctoral researcher Lingfeng Zhou led the four-year study, which tested solutions for minimizing the amount of corrosive chromium gas that evaporates from solid oxide fuel cell components during power generation. 

Two stainless steel alloys that could be used to manufacture certain parts of the fuel cells performed exceptionally well in Zhou’s tests. He explained that a solid oxide fuel is a “highly efficient energy conversion device” with the ability to produce electricity from versatile fuels such as hydrogen and fossil fuels. 

“The ceramics used in solid oxide fuel cells have to run at temperatures ranging from 500 to 1,000 degrees Celsius [932–1,832 °F],” says Zhou. “The operating temperature is their largest disadvantage, but they offer high combined heat and power efficiency, long-term stability, fuel flexibility, low emissions, and relatively low cost.” 

As Zhou continues, “Because of their high fuel-to-power conversion efficiency and minimal adverse influence on the environment, solid oxide fuel cells have the potential to be a platform for future power generation technologies—but they have to be able to last for at least 40,000 hours of operation with minimal degradation.” 

At sustained high temperatures, fuel cell components manufactured from metal alloys rich in iron and nickel can generate chromium gases, contaminating the environment and leading to deterioration of fuel cells. To counteract that problem, Zhou’s team identified two recently developed stainless steel alloys that are cheap, oxidation resistant and—under conditions equivalent to those of a power plant in operation—form a protective layer of aluminum oxide that is ”essentially free of voids or cracks,” says Zhou. 

After the first 5,000-hour test cycle, those alloys still had not released detectable levels of corrosive chromium gas, which represents “excellent potential for the long-term,” according to Zhou. “Their aluminum oxide layer is immune to the effect of water vapor, thermodynamically stable, and provides far superior protection in many industrial environments as compared to a conventional alloy.” 

“Long-term operation without degradation is of great importance for solid oxide fuel cell stacks, and the next step is to apply these alloys in fuel cell industries,” adds Zhou. 

The study was published in the International Journal of Hydrogen Energy and supported by the U.S. Department of Energy. 

Source: West Virginia University – Statler College Media Hub, https://media.statler.wvu.edu