MIT Battery Researchers Grow Nanowires Using A Virus

Typically when people think of a “virus” they think of the cause of an illness, or something bad happening to their computer, but researchers at MIT say a genetically modified virus may improve the cars we drive one day.

In a paper published in the journal Nature Communications, work on lithium-air batteries found that adding viruses to the production of nanowires could create durable microscopic wires with increased surface area and improved electrochemical potential and other promising implications.

These wires are about the width of a red blood cell – approximately 80 nanometers across – and a virus called M13 is showing great potential. The work was described in the published article co-authored by graduate student Dahyun Oh, professors Angela Belcher and Yang Shao-Horn, and three others.

Their initial findings outline a wire that can capture molecules of metals from water and bind them into structural shapes. Belcher said “a favorite material” for a lithium-air battery’s cathode, manganese oxide was actually made by the viruses.

Contrasting with wires “grown” through conventional chemical methods, these virus-built nanowires have a rough, spiky surface, which dramatically increases their surface area.

This provides a “big advantage” for lithium-air charging and discharging, said Belcher, who is the W.M. Keck Professor of Energy and a member of MIT’s Koch Institute for Integrative Cancer Research.

Belcher, said the biosynthesis is “really similar to how an abalone grows its shell.” An abalone does so by accumulating calcium from its surrounding seawater and depositing it into a solid, linked structure.

The nanowire production process is relatively benign, and done at room temperature, instead of at high temperatures and with hazardous chemicals involved. This, said Jie Xiao, a research scientist at the Pacific Northwest National Laboratory, is encouraging.

The work is “a great contribution to guide the research on how to effectively manipulate” catalysis in lithium-air batteries,” she said, “and the “novel approach … not only provides new insights for lithium-air batteries,” but also “the template introduced in this work is also readily adaptable for other catalytic systems.”

The work is still in early stages and only looked at the cathode and only 50 charge cycles have been documented so far. Other core components including the electrolyte are still being researched. MIT estimated the potential for its work could improve battery energy density by 2-3 times.

Researchers are however heartened to the point that they’re discussing a possible path toward production one day.


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