Electronics are now part of our daily portables and are used in phones, iPads and laptops. They're also becoming something we use, like wearable health trackers and watches. However, to some extent, the capabilities of such wearables have been limited by the battery. Bigger, stronger batteries would be needed to do more.
However, larger batteries also require larger devices that can be uncomfortable for most users. Some of these electronics also present security risks from time to time.
Researchers are working to resolve this issue. For example, a Stanford team recently found a viable solution to this problem. They have developed a soft, “stretchable” battery that uses a specific type of plastic (or polymer) that is much safer than the potentially flammable formulations typically used in regular batteries.
“Until now we haven’t had a power source that can stretch and bend like our bodies, so we can design electronics that people can use comfortably,” shared Zhenan Bao, a chemical engineer. Using polymers or plastics in batteries is nothing new. For a long time, lithium-ion batteries used polymers as electrolytes. Electrolytes are the energy source that transports negative ions to the positive pole of the battery.
Until recently, most of these polymeric electrolytes were simply too dangerous to use. They were used in the form of fluid gels that could sometimes burst into flames or leak. To avoid these risks, this team of Stanford researchers created a solid, stretchable polymer. It is not “sticky” nor does it leak, but it is still capable of carrying charge from one pole of the battery to the other.
When researchers tested this battery in the laboratory, it maintained constant power even when it was stretched, bent or compressed to half its total length. The prototype of this battery is a small thumbnail-sized device that stores about half the energy compared to a normal battery of similar size.
One of the team members, David Mackanic, says his team is working further to increase the energy density of this stretchable battery and create larger versions of this device. They will continue working to demonstrate performance even outside the laboratory.
The quest to develop such a flexible battery isn't just limited to Stanford. A team of MIT engineers also recently developed a process that could become the key to stretchable electronics. They have finally found a way to overcome the rigidity of computer chips located at the core of all electronic devices. The goal is to make flexible and more multifunctional electronic devices.
The MIT team believes the process could be used to produce stretchable electronic films for a variety of purposes, including solar-powered skin or electronic fabrics.
