Some of the most fascinating advancements in clean technology have been in batteries. Researchers have not only made huge strides in increasing battery life and energy storage capacity, but they've found alternative materials that work as well as traditional ones while being more sustainable. They've also addressed other issues that might not seem as obvious like how to make a battery that's meant to have a short life.
When we talk about clean technology we focus a lot on how to increase the lifetimes of electronics both big and small in order to lower their environmental impact, but some devices are meant to be temporary. Things like short term medical implants and environmental sensors are built to have a specific duration of use and then they have to be recovered.
Having a battery that is able to break down at the end of the life gets us one step closer to a device that could basically disappear when its job is done.
Researchers at Iowa State University have developed a battery that quickly destructs when dropped in water. The lithium ion battery can produce 2.5 volts and can power a desktop calculator for about 15 minutes. When submerged in water, it dissipates in just 30 minutes. The university says this is the first so-called "transient" battery to have the power, stability and shelf life needed 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 in their paper just published in the Journal of Polymer Science, Part B: Polymer Physics.
The battery is only about 1 millimeter thick, 5 millimeters long and 6 millimeters wide. It is made up of eight layers, which include the anode, cathode and electrode and the whole thing is wrapped in a polyvinyl alcohol-based polymer. While the technology is very similar to commercial battery technology, it distinguishes itself when it's dropped in water.
When submerged, the casing swells and breaks apart the electrodes, then dissolves away. The researchers stressed that there are nanoparticles that don't completely disappear, but they do disperse.
If this type of battery is paired with an equally self-destructive device in the future, we could see patients avoid the pain of having medical implants removed or environmental sensors that could wash away in the rain.