Recently, lithium-air batteries have become popular amongst researchers for their potential to drastically increase power per battery weight, which could have profound impacts on electric cars and their overall range.
But in order for this tech to become viable, it is essential that we find better, more durable materials for the batteries’ electrodes, while also improving the number of charging-discharging cycles these batteries can withstand.
A revolutionary new process may offer a solution to this issue. In what sounds like a brilliant, yet dangerous idea from a Sci-Fi novel, researchers from the Massachusetts Institute of Technology have introduced genetically modified viruses to the nanowires of lithium-air batteries as a way to increase efficiency.
The team’s primary focus was on finding ways to expand the surface area of these nanowires (which function as the batteries electrodes), and thus increase the area where electrochemical activity takes place during charging or discharging of the battery.
According to the MIT study:
The researchers produced an array of nanowires, each about 80 nanometers across, using a genetically modified virus called M13, which can capture molecules of metals from water and bind them into structural shapes. In this case, wires of manganese oxide — a “favorite material” for a lithium-air battery’s cathode — were actually made by the viruses.
What the team found was that battery performance can be greatly enhanced through the use of genetically modified viruses. By introducing the GMO, nanowires develop microscopically rough, spikey surfaces, resulting in a much greater surface area.
As opposed to isolated wires, the viruses naturally produce a three-dimensional structure of cross-linked wires, which provides greater stability for an electrode. Consequentrly, the additional space brought about a greatly increased ability to charge and discharge, which has the potential to significantly cut the charge times of electric cars.
This virus-aided method of production includes a number of secondary advantages as well, including the fact that it doesn’t rely on high temperatures of hazardous chemicals, and that it can be carried out at room-temperature via a water-based process.
For those worried about the potential ramifications and implications of combining biological viruses with high technology, Professor Angela Belcher, the WM Keck Professor of Energy and an affiliate of MIT’s Koch Institute for Integrative Cancer Research, alleviates this concern a bit by explaining that this method of biosynthesis is “really similar to how an abalone grows its shell.”
Further, she mentions that, while these experiments used viruses for the molecular assembly, once the best materials for such batteries are found and tested, actual manufacturing might be done in a different way. This has happened with past materials developed in her lab, “The chemistry was initially developed using biological methods, but then alternative means that were more easily scalable for industrial-scale production were substituted in the actual manufacturing.”
While still in its early stages, there is much more work that needs to be done before a commercially viable lithium-air battery could be developed. This research only looked at the production of one component, the cathode; other essential parts, including the electrolyte (the ion conductor that lithium ions traverse from one of the battery’s electrodes to the other) require further research to find reliable, durable materials. Also, while this material was successfully tested through fifty cycles of charging and discharging, to be considered for practical use, a battery must be capable of withstanding thousands of these cycles.
This is a good start, let’s just hope we don’t have to put our cars on a cycle of antibiotics.
