Viruses can be genetically programmed to first grow an iron phosphate shell, and then bind to carbon nanotubes (model shown). The resulting material is highly conductive, resulting in fast movement of ions and electrons through a lithium ion battery cathode. Inset: A battery with a cathode based on a virus (the biological kind) powers a green LED.
"Researchers have genetically engineered biological viruses to form the anode and cathode of a battery. MIT researcher Angela Belcher and her colleagues manipulated the genes of a harmless virus so that the bug coats itself in tiny iron phosphate particles and connects to highly-conductive carbon nanotubes. From Science News:
Ions and electrons can move through smaller particles more quickly. But fabricating nano-sized particles of iron phosphate is a difficult and expensive process, the researchers say.
So Belcher’s team let the virus do the work. By manipulating a gene of the M13 virus to make the viruses coat themselves in iron phosphate, the researchers created very small iron phosphate particles.
“We’re using a biological template that’s already on the nanoscale,” Belcher says.
Tweaking a second gene made one end of the virus bind to carbon nanotubes, which conduct energy well. The resulting network of iron phosphate-coated viruses and carbon nanotubes formed a highly conductive cathode, one that ions and electrons could move through quickly."