Scientists at the Iowa State University have developed a self-destructing lithium-ion battery that can dissolve in water over a period of time of 30 minutes. According to the researchers, self-destructing electronics could be used for keeping military secrets – not unlike in a Bond movie – or they could just as well "save patients the pain of removing a medical device". The technology could also be utilized for creating environmental sensors that can "wash away in the rain".
Research on devices capable of self-destruction led to the creation of a new field of study called "transient electronics". The idea is to have computing devices and electronics capable of performing various functions for a limited period of time, until they are exposed to heat, light, or liquid to trigger their self-destruction. The transient battery has been in development "for years" and was created by Iowa State University assistant professor of mechanical engineering, Reza Montazami, and his team, including assistant professor of mechanical engineering Nastaran Hashemi; postdoctoral research associate Simge Çinar; graduate students Reihaneh Jamshidi and Yuanfen Chen; undergraduate student Emma Galleos; and Kathryn White, an intern at the Ames Laboratory of the US Department of Energy. The transient lithium-ion battery measures 1 millimeter in thickness, is 5 millimeters long and 6 millimeters wide, and can deliver 2.5 volts, or enough energy to power a calculator for roughly 15 minutes. Although the battery components, structure, and electromechanical reactions are very similar to commercially available battery technology – according to Reza Montazami – once dropped in water the polymer casing swells, breaks apart the electrodes and then dissolves. However, according to Montazami the battery contains nanoparticles that won't degrade, but will disperse once the casing starts breaking the electrodes apart. This is a process that he calls "physical-chemical hybrid transiency".
Reza Montazami states that this is "the first transient battery to demonstrate the power, stability and self life for practical use", but there are still a number of technical hurdles that need to be overcome before the battery will be capable of storing more electrical current. On the other hand, according to the paper, while transient batteries with a higher capacity could deliver more energy, they can also require more time to self-destruct. As such, the paper also suggests that devices and applications requiring more energy can be connected to multiple smaller batteries. Either way, Montazami also reveals that creating these batteries was a difficult process requiring repeated attempts, and added that the main motivator for keeping the scientist group working on the project was "the materials science part of this. This is a challenging materials problem, and there are not many groups working on similar projects". Meanwhile, from a more consumer-grade perspective, other companies including Oakridge Global Energy Solutions are working on developing solid state batteries for commercial use, to replace lithium-ion technology.