COLLEGE PARK, Md.–Viruses have a bad rep–and rightly so. The ability of a virus to quickly and precisely replicate itself makes it a destructive scourge to animals and plants alike.

Now an interdisciplinary team of researchers at the University of Maryland’s A. James Clark School of Engineering and College of Agriculture and Natural Resources, brought together by Professor Reza Ghodssi, is turning the tables. It is harnessing and exploiting the “self-renewing” and “self-assembling” properties of viruses for a higher purpose: to build a new generation of small, powerful and highly efficient batteries and fuel cells.

The rigid, rod-shaped Tobacco mosaic virus (TMV), which under an electron microscope looks like uncooked spaghetti, is a well-known and widespread plant virus that devastates tobacco, tomatoes, peppers, and other vegetation.

But in the lab, engineers have discovered that they can harness the characteristics of TMV to build tiny components for the lithium ion batteries of the future. They can modify 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.

Then, they coat 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.

New batteries are a leap forward

As a result, the researchers can greatly increase the electrode surface area and its capacity to store energy and enable fast charge/discharge times. TMV becomes inert during the manufacturing process; the resulting batteries do not transmit the virus.

The new batteries, however, have up to a 10-fold increase in energy capacity over a standard lithium ion battery.

“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.”

TMV’s nanostructure is the ideal size and shape to use as a template for building battery electrodes. Its self-replicating and self-assembling biological properties produce structures that are both intricate and orderly, which increases the power and storage capacity of the batteries that incorporate them. Because TMV can be programmed to bind directly to metal, the resulting components are lighter, stronger and less expensive than conventional parts.

“Virus-enabled nanorod structures are tailor-made for increasing the amount of energy batteries can store. They confer an order of magnitude increase in surface area, stabilize the assembled materials and increase conductivity, resulting in up to a10-fold increase in the energy capacity over a standard lithium ion battery,” Chunsheng Wang, a professor in the Department of Chemical and Biomolecular Engineering, said.

The use of the TMV virus in fabricating batteries can be scaled up to meet industrial production needs.

At the same time, very tiny microbatteries can be produced using this technology.

Funding for the research comes from the National Science Foundation, the Department of Energy Office of Basic Energy Sciences, the Maryland Technology Development Corporation, and the Laboratory for Physical Sciences at the University of Maryland. James Culver’s work is conducted in collaboration with Purdue University professor Michael Harris.