The MIT researchers were trying to develop a new battery, but it didn’t work out that way. Instead, thanks to an unexpected finding in their lab tests, what they discovered was a whole new way of producing the metal antimony—and potentially a new way of smelting other metals, as well.
The discovery could lead to metal-production systems that are much less expensive and that virtually eliminate the greenhouse gas emissions associated with most traditional metal smelting. Although antimony itself is not a widely used metal, the same principles may also be applied to producing much more abundant and economically important metals such as copper and nickel, the researchers say.
The surprising finding is reported this week in the journal Nature Communications, in a paper by Donald Sadoway, the John F. Elliott Professor of Materials Chemistry; postdoc Huayi Yin; and visiting scholar Brice Chung.
“We were trying to develop a different electrochemistry for a battery,” Sadoway explains, as an extension of the variety of chemical formulations for the all-liquid, high temperature storage batteries that his lab has been developing for several years. The different parts of these batteries are composed of molten metals or salts that have different densities and thus inherently form separate layers, much as oil floats on top of water. “We wanted to investigate the utility of putting a second electrolyte between the positive and negative electrodes” of the liquid battery, Sadoway says.