Viruses and lithium batteries might seem to have little in common, but researchers at the Massachusetts Institute of Technology in the US have shown otherwise. Angela Belcher and co-workers have used the M13 virus to make cobalt oxide nanowires that could significantly improve the performance of batteries when used as electrodes.

Belcher and colleagues used standard virus biotemplating techniques to grow both cobalt oxide nanowires and cobalt oxide–gold nanoparticle hybrid wires. The cobalt oxide nanowires were grown by incubating the virus templates in cobalt chloride solution for 30 minutes at room temperature, followed by reduction with sodium borohydride and oxidation in water. A major advantage of the virus-based approach is that the nanowires can then self-assemble into larger structures.

Cobalt oxide electrodes could triple the charging capacity of lithium batteries compared with existing devices, which use carbon-based anodes, and the gold–cobalt oxide hybrid promises even better performance.