One Virus You’ll Actually Want
Posted by agoldste on April 14, 2009
Credit to Steve Lee, atbatt.com
Back in 2006, MIT researcher Angela Belcher and her team scientists took a nano-sized virus and, by manipulating its genes, made it collect cobalt oxide and gold—thus creating a very small high-energy-dense anode (the negatively charged end of a battery). Recently, Belcher’s team has taken the M13 virus, a common bacteriophage (i.e. it eats bacteria, not humans), and tweaked its genetic code so that it coats itself in iron phosphate—effectively generating nanoparticles of iron phosphate without using an expensive pressure-cooking process. The result? A tiny, powerful, efficient battery.
The most common type of battery used in portable electronic devices (everything from watches, to computers, to pacemakers) is the lithium battery. In order to provide power to these devices, lithium ions and accompanying electrons flow from the negatively charged end of the battery (called the anode), through an electrolyte, to the positively charged end of the battery (called the cathode). The flow of these ions/electrons creates electric current and is what powers our various handheld gadgets.
What engineers, scientists, and manufacturers are working to solve is the challenge of making these batteries store the greatest possible amount of energy while being able to deliver the energy as efficiently as possible. On one hand, certain materials possess greater energy density than others—that is, they can store more energy for their size and weight compared with other materials of equal size/weight. However, efficiency is often sacrificed at the cost of energy density. One such example is the case of iron phosphate, the material of which some rechargeable lithium batteries’ cathodes are composed. Iron phosphate, when it reacts with (or “accepts”) lithium, has a high capacity to store energy. However, iron phosphate is not a very good conductor, and the result is slower ion/electron movement and, therefore, a less efficient battery.
One solution to this problem is to decrease the size of the “passageways” or particles through which the ions and electrons move. However, in cases such as iron phosphate, scaling the material down to nano-sized particles is a laborious, expensive process—or it was until a team of MIT researchers stepped in. Back in 2006, Angela Belcher and her team of MIT scientists manipulated the genes of a nano-sized virus so it would collect cobalt oxide and gold—metal oxides that would increase the energy density of the anode they were creating. Now, Belcher and her team have taken the M13 virus and altered its genetics to a) make it coat itself in iron phosphate and b) cause the virus to bind to carbon nanotubes on one end, thus completing their itty-bitty high-energy-density battery by fashioning the “other end”: the cathode.
Smaller, lighter, more efficient, longer-lasting—these are the qualities needed to make batteries for all of our “take it everywhere” gizmos—including hybrid cars. That is one possible “application goal” for the research, as the lab continues its work on a second generation battery for commercial production.
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