Special Viruses Recharge Batteries
MIT researchers say they've combined nanotechnology with genetically engineered viruses to build batteries that could power hybrid cars and cell phones.
The university announced Thursday that the viruses, which infect bacteria but are harmless to humans, build the positively and negatively charged ends of lithium-ion batteries. The batteries, according to MIT, have the same energy capacity and power performance as state-of-the-art rechargeable batteries that are being considered to power plug-in hybrid cars and personal electronic devices.
"In lab tests, batteries with the new cathode material could be charged and discharged at least 100 times without losing any capacitance," MIT said in a report on the discovery.
Last week, MIT President Susan Hockfield took a prototype of the battery to the White House, where she discussed federal funding for clean-energy technologies with President Barack Obama.
This news comes just a few weeks after MIT announced that scientists there had developed technology that could enable lithium-ion batteries to charge in seconds instead of hours. They're hoping the advance could lead to smaller, faster-charging batteries that could be used in cell phones and other devices.
Another MIT research team announced in February that a new energy-efficient chip designed there may one day be able to run implantable medical devices using human body heat as an energy source. The new chip, which is in the proof-of-concept stage, uses 10 times less power than traditional chips. And that could increase battery life.
In Thursday's announcement, the genetically engineered viruses are able to actually build the battery anodes.
The MIT report explains that in a traditional lithium-ion battery, the lithium ions flow between a negatively charged anode, which is usually graphite, and the positively charged cathode, which is usually cobalt oxide or lithium iron phosphate. Angela Belcher, the MIT materials scientist who led the research team, said that engineered viruses that could build an anode by coating themselves with cobalt oxide and gold, and then self-assemble to form a nanowire, were created years ago.
More recently, the research team engineered viruses that coat themselves with iron phosphate. Then they then latch onto carbon nanotubes to create a network of highly conductive material.
Electrons, according to MIT, can travel along the networks of carbon nanotubes, transferring energy very quickly. Adding the carbon nanotubes, the university reports, increases conductivity without adding "too much weight" to the battery.
Batteries built with this technology would likely be lightweight and flexible enough to take the shape of their container.