Researchers have significantly improved the performance of lithium-air batteries by unleashing a genetically modified virus onto the microscopic electrode wires.
Lithium air batteries have received much attention because they are able to increase power output without having to increase weight, a quality that could allow electric cars to have greater driving range. However, engineers have struggled to find durable materials required for the battery’s electrode, to increase the number of charging cycles the batteries could withstand.
Researchers from MIT found a way to overcome this limitation by adding bioengineered viruses to nanowires during the production stage. These nanowires are about the thickness of one red blood cell.
The virus, called M13, increases the surface area of the wire, therefore increasing the area where electrochemical activity takes place when the batteries are charged or discharged.
The nanowire, with the help of M13, pulls molecules of metal from room temperature water. The virus then binds the metal into specific structural shapes. M13 produces manganese oxide wires, which have the rough, spiky surface required for the desired increase in surface area.
The final part of the process is adding a small amount of palladium metal to increase the electrical conductivity of nanowires. These modifications show that it may soon be possible to create a fully functional battery with an energy density two to three times greater than today’s best lithium-air batteries.
Video: Better batteries through biology
Press release: http://news.discovery.com/tech/biotechnology/mutated-virus-helps-builds-a-better-battery-131114.htm
Journal article: http://www.nature.com/ncomms/2013/131113/ncomms3756/abs/ncomms3756.html