Yale engineers are using nanotechnology to reinvent the battery.
Chemical and electrical engineering assistant professor Andre Taylor and associate professor of mechanical engineering Jan Schroers are working together to use their respective fields in the application of nanowires to the catalyst system of batteries. Their research, which will be published in the April issue of the journal ACS Nano, details the construction of their new fuel cell, which could potentially act as a battery for cellphones and laptops, and would be ideal for converting biofuel into electricity, Taylor said. But while the technique used by Taylor and Schroers is innovative and shows promise, experts interviewed said that it will not to make a dramatic change in the performance of fuel cells.
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The research hinges on the application of a special combination of metals called Bulk Metallic Glass or BMG, an alloy of metals that acts like a plastic. The final product was a cell that operates at lower temperatures than current battery models, and which generates higher amounts of electricity for longer periods of time.
“BMG has all the same properties of a metal but with the amorphous nature of glass,” said Taylor. “It’s been around for a while, but no one has looked at it from an electrochemical perspective.”
Schroers began the project by testing various combinations of platinum, copper, nickel and phosphorus in up to 1,000 different mixtures, or alloys, a day to discover that perfect composition which would enable the alloy to acquire the properties of a polymer.
While Schroers ran experiments adjusting the composition of the actual material of the nanowires, Taylor studied the ways in which the nanowires would improve the durability of the fuel cell, performing comparisons with the existing models, Taylor said.
“A normal catalyst loses 60 percent activity with every 1,000 cycles,” Taylor added. “This new fuel cell goes on much longer retaining 96 percent functioning for 1,000 cycles.”
Two years ago when Taylor heard Schroers give a talk on his application of BMG, he said he immediately realized its potential for the world of fuel cells. Schroers had been working on developing BMG as a substitute for plastic and glass in the manufacture of perfumes and jewelry instead of its more traditional use in construction. When the two got to talking, they realized that not only could BMG be used as an inexpensive and energy-efficient replacement for the current platinum catalyst in fuel cells, but it was also environmentally friendly, Taylor said.
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But experts remain skeptical about the true efficiency of BMG as a method of increasing the energy output and durability of fuel cells.
“There are many different ways to improve a catalyst, so it’s difficult to say how good this method is or if it will solve the problem of the low rate of oxidation reduction reactions in the fuel cell,” Boris Merinov, Caltech director of fuel cell research and technology, said.
Princeton University chemical engineering professor Jay Benziger said that there are many other equally, if not more, important problems with fuel cells than the aspects Taylor and Schroer’s research explores.
“One of my hesitancies about being overly enthusiastic about the catalyst is that over the last 15-20 years, three to four new catalysts have been introduced and have not had the big impact expected,” he said.
Schroers is currently working on constructing a fuel cell entirely out of BMG that is small enough to be used in a laptop or a cellphone.