MIT Continues to Advance Virus-Built Battery Technology
April 2, 2009 – 4:28 pm
Professor Angela Belcher holds a device powered by a virus-built battery that she helped engineer. (Image Courtesy of Donna Coveney)
Researchers at MIT have reported that they have genetically engineered viruses to build both the positively and negatively charged ends of a lithium-ion battery. In August of last year, the researchers had succeeded in coaxing viruses to construct the anode component of a battery. In their most-recent work, the researchers focused on building a cathode to pair up with the anode. According to Angela Belcher, an MIT materials professor who led the research, cathodes were more difficult to construct than anodes. The novel batteries could be used to power a range of personal electronic devices, according to professor Belcher.
The virus-built batteries also can be manufactured inexpensively. And the synthesis does not require harmful solvents and the materials used to construct the battery are non-toxic.
The researchers genetically engineered viruses that first coat themselves with iron phosphate, then grab hold of carbon nanotubes to create a network of highly conductive material.
Because the viruses recognize and bind specifically to certain materials, each iron phosphate nanowire can be electrically “wired” to conducting carbon nanotube networks. Electrons can travel along the carbon nanotube networks, percolating throughout the electrodes to the iron phosphate and transferring energy in a very short time.
The viral strain used to construct the batteries is harmless to humans.
The team found that incorporating carbon nanotubes increases the cathode’s conductivity without adding too much weight to the battery. In lab tests, batteries with the new cathode material could be charged and discharged at least 100 times without losing any capacitance. That is fewer charge cycles than currently available lithium-ion batteries, but “we expect them to be able to go much longer,” Belcher says.
Tweezers hold the device used to test new microbattery component.
The prototype is packaged as a typical coin cell battery, but the technology allows for the assembly of very lightweight, flexible and conformable batteries that can take the shape of their container.
Last week, MIT President Susan Hockfield took the prototype battery to a press briefing at the White House where she and U.S. President Barack Obama spoke about the need for federal funding to advance new clean-energy technologies.
Now that the researchers have demonstrated they can wire virus batteries at the nanoscale, they intend to pursue even better batteries using materials with higher voltage and capacitance, such as manganese phosphate and nickel phosphate, said Belcher. Once that next generation is ready, the technology could go into commercial production, she said.
More information is available on the research from Science Daily.
Tags: Angele Belcher, batteries, MIT, virus
