Tuesday Dec 07, 2010

Harnessing viruses to build a better battery

NewImage.jpgOk, now this is cool. You may not think so, but I sure do. I spent a fair amount of time researching battery types and capacities, as well as costs, and to say that it is a dizzying and complicated area is to massively understate the problem.

Considering that just about everything we use these days needs (or could benefit from) a small, lightweight and energy-dense battery (you can't really get all 3 at this time), this could be a huge step forward.

Keep in mind that one of the reasons that electric cars don't really 'work' for most applications is that the weight of the required batteries decreases the efficiency of the vehicle and, at some point, becomes counterproductive. It's all about energy density. It's the same reason that personal jet-packs don't work: You can't carry enough fuel to fly any great distance.

So if you can increase the energy density of the battery, without significantly increasing its overall weight, you win. This reported 10-fold increase in energy capacity would make this a winner.

The first virus to be discovered was the Tobacco mosaic virus (TMV) back in 1898. It is a rigid, rod-shaped virus that, under an electron microscope, looks like uncooked spaghetti. This widespread virus devastates tobacco, tomatoes, peppers and other plants but in the lab, engineers at the University of Maryland's A. James Clark School of Engineering and College of Agriculture and Natural Resources, have managed to harness and exploit the self-replicating and self-renewing characteristics of TMV to build tiny components for more efficient lithium-ion batteries.

To create the highly efficient batteries the researchers first modified the TMV rods to bind perpendicularly to the metallic surface of a battery electrode and arrange the rods in intricate and orderly patterns on the electrode. Because TMV can be programmed to bind directly to metal, the resulting components are lighter, stronger and less expensive than conventional parts. They then coated the rods with a conductive thin film that acts as a current collector and finally the battery's active material that participates in the electrochemical reactions.

10-fold increase in energy capacity

This results in an electrode with a greatly increased surface area that increases its capacity to store energy and enables fast charge/discharge times. The new batteries boast up to a 10-fold increase in energy capacity over a standard lithium-ion battery. The researchers say that the use of the TMV virus in fabricating batteries can be scaled up to meet industrial application needs. And because the TMV becomes inert during the manufacturing process, the batteries do not spread the virus.

"The resulting batteries are a leap forward in many ways and will be ideal for use not only in small electronic devices but in novel applications that have been limited so far by the size of the required battery," said Ghodssi, director of the Institute for Systems Research and Herbert Rabin Professor of Electrical and Computer Engineering at the Clark School.

"The technology that we have developed can be used to produce energy storage devices for integrated microsystems such as wireless sensors networks. These systems have to be really small in size - millimeter or sub-millimeter - so that they can be deployed in large numbers in remote environments for applications like homeland security, agriculture, environmental monitoring and more; to power these devices, equally small batteries are required, without compromising in performance," added Ghodssi.

(Via Harnessing viruses to build a better battery.)

That may be too information-dense for some, but suffice to say that it's kind of cool that it is using the Tobacco mosaic virus to increase the energy density. It's not clear if this type of technology could be useful in larger batteries like those required for electric cars and other larger applications, but being applicable to small (as in really small) devices makes it very interesting to me. If this technology is able to come to market in a useful package, it would certainly validate a certain amount of the research bets that we made by putting relatively power-hungry 32-bit processors on our sensor platform.

As an side, it also looks like some of the smart folks at MIT have done something similar that they think could be used in larger applications like electric cars, etc.

Using a virus that infects bacteria but is harmless to humans known as a bacteriaphage, the team were able to show it is possible to build both the positively and negatively charged ends of a lithium-ion battery using genetically engineered viruses. According to Angela Belcher, the MIT materials scientist who led the research team, the resultant virus-produced batteries have the same energy capacity as state-of-the-art rechargeable batteries being considered to power plug-in hybrid cars, and they could also be used to power a range of personal electronic devices.The benefits of this process is that it's both cheap and green, since it takes place at or below room temperature in an environmentally benign process that requires no harmful organic solvents and no toxic materials.

(Via New virus-built battery could power cars, electronic devices.)

So there you have it. We're finally going to extract some revenge on the much-maligned virus and bacteria and make them work for us for a change. Until, of course, the batteries become self-aware, at which point Sky-Net will be complete and we'll be toast.




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