‘Transient’ battery self destructs in water

Technology News | August 8, 2016

By Rich Pell

Reza Montazami, an Iowa State University assistant professor of mechanical engineering and an associate of the U.S. Department of Energy’s Ames Laboratory, has developed a self-destructing, lithium-ion battery capable of delivering 2.5 volts and dissolving or dissipating in 30 minutes when dropped in water. The battery can power a desktop calculator for about 15 minutes and could be used to drive a secure device for a fixed, short period of time.

Montazami said it’s the first transient battery to demonstrate the power, stability and shelf life for practical use. “Any device without a transient power source isn’t really transient,” he says. “This is a battery with all the working components. It’s much more complex than our previous work with transient electronics.”

The transient battery is made up of eight layers, including an anode, a cathode and the electrolyte separator, all wrapped up in two layers of a polyvinyl alcohol-based polymer. The battery measues 5 x 6 mm and is 1 mm thick, and when it is dropped in water, the polymer casing swells, breaks apart the electrodes and dissolves away.

Montazami is quick to say the battery doesn’t completely disappear. The battery contains nanoparticles that don’t degrade, but they do disperse as the battery’s casing breaks the electrodes apart.

Larger batteries with higher capacities could provide more power, but they also take longer to self-destruct, he says, although higher power levels could be acheived by connecting to several smaller batteries.

The technology would compete with fuel cells powered by urine or waste water, some of which have been developed with paper to be temporary. For more, see the paper “Physical–chemical hybrid transiency: A fully transient li-ion battery based on insoluble active materials.”