By Kennedy Maize
Is biology the key to improved battery performance? Researchers in a recent issue of Science magazine describe how genetically-engineered viruses could boost the power of lithium ion batteries, expected to be the batteries of choice for plug-in hybrid vehicles.
A research team led by scientists at the Massachusetts Institute of Technology used genetic modification and nanotechnology to improve the ability of Li+ ion batteries to deliver more energy at higher rates of charging and discharging.
Say the researchers, “This benign low temperature biological scaffold could facilitate fabrication of electrodes from materials that have been excluded because of their extremely low electronic conductivity.” The research paper notes, “Development of materials that deliver more energy at high charge/discharge rates is important for high power applications including portable electronic devices and hybrid electric vehicles.”
The paper notes, “Lithium bio battery electrodes store and release electrical energy by insertion of Li+ ions and electrons through the electrode materials. Therefore, increasing transport of Li+ ions and electrons can enhance energy storage at high charge and discharge rates.”
The MIT team was able to manipulated two genes from a common virus used in nanotechnology research (M13) to attach iron phosphate, an excellent conductor, to carbon nanotube networks to create a structure for more efficient electrodes.
Iron phosphates, the report says, are “promising Li+ ion battery positive electrode materials due to their lower toxicity, lower cost, and improved safety through improved chemical, thermal, and structural stability for high power applications.” But practical use of iron phosphate chemistry has been limited by poor charge and discharge rates and fading of capacity after too-few cycles of use.
The research paper claims, “By developing this two-gene system with a universal handle to pick up electrically conducting carbon nanotubes, we facilitated a method to realize nanoscale electrical wiring for high power lithium ion batteries using basic biological principles.”
The Army’s Institute of Collaborative Biotechnologies and the National Science Foundation, along with support from the Korean government, funded the research.