Now, a quick-destructing battery to power 'transient' devices

Whether it is keeping military secrets out of enemy hands or saving patients the pain of removing a medical device, everything seems to come down to one essential bit

Iowa State University's Reza Montazami, who has been working on transient technology for years, recently 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.

Montazami said it's the first transient battery to demonstrate the power, stability and shelf life for practical use.

"Unlike conventional electronics that are designed to last for extensive periods of time, a key and unique attribute of transient electronics is to operate over a typically short and well-defined period, and undergo fast and, ideally, complete self-deconstruction and vanish when transiency is triggered," the scientists wrote.

"Any device without a transient power source isn't really transient," Montazami said. "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 itself is tiny - about 1 millimeter thick, 5 millimeters long and 6 millimeters wide. Montazami said the battery components, structure and electrochemical reactions are all very close to commercially developed battery technology.

But, when you drop it 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.

He calls that "physical-chemical hybrid transiency."

And what about applications that require a longer-lasting charge? Larger batteries with higher capacities could provide more power, but they also take longer to self-destruct, according to the scientists' paper. The paper suggests applications requiring higher power levels could be connected to several smaller batteries.

Montazami and his team recently published their discovery in the Journal of Polymer Science.