Technique improves the efficacy of fuel cells [View all]
https://www.seas.harvard.edu/news/2016/05/technique-improves-efficacy-of-fuel-cells[font face=Serif][font size=5]Technique improves the efficacy of fuel cells[/font]
[font size=4]Research demonstrates a new phase transition from metal to ionic conductor[/font]
By Leah Burrows | May 16, 2016
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todays solid oxide fuel cells have a major problem. Over time, the fuel reacts with the electrolyte to degrade its efficiency. Soon, this chemical bouncer is letting both protons and electrons through, causing the electrical current going through the outside circuit to become weaker and weaker.
A solution to this problem may have been found by
Shriram Ramanathan, Visiting Scholar in Materials Science and Mechanical Engineering at SEAS, and his graduate student You Zhou. The pair discovered that by designing the electrolyte on the quantum level, they could create a material that becomes more robust when exposed to fuel.
Ramanathan and his team used a perovskite-structured nickelate as their electrolyte. On its own, the nickelate conducts both electrons and ions, like protons, making it a pretty lousy electrolyte. But the team coated the surface of the nickelate with a catalyst and then injected or doped it with electrons. These electrons joined the electron shell of the nickel ion and transitioned the material from an electron conductor to an ion conductor.
Now, ions can move very quickly in this material while at the same time electron flow is suppressed, said Zhou. This is a new phenomenon and it has the potential to dramatically enhance the performance of fuel cells.[/font][/font]