The virus batteries are non-toxic and could be manufactured in a cheap and environmentally friendly way.

Three years ago, the team led by Professor Belcher from MIT showed that their engineered viruses could build an anode by coating themselves with cobalt oxide and gold and self-assembling to form a nanowire. However, this only went half-way to building a self assembling battery as a high powered cathode was needed to match the anode. Cathodes are harder the build because they need to be highly conducting but the best materials for cathodes tend to be insulating.

To solve this problem, researchers from MIT used genetically engineered viruses that coat themselves with iron phosphate and then attach to carbon nanotubes to create a network of highly conductive material. The viruses used are a common bacteriophage that is harmless to humans.

Using carbon nanotubes gives a highly conductive and lightweight cathode. Other advantages of using a nanotube structure include the possibility of making flexible and conformable batteries that take the shape of their container.

Now the group has demonstrated that they can produce virus batteries at the nanoscale, they intend to use materials with higher voltage and capacitance, such as manganese, phosphate and nickel phosphate. The group hope that the next generation of virus batteries could go into commercial production.

By Leila Sattary