Researchershave created printable solid-state batteries that can be printed in any conceivable shape and can be seamlessly embedded into a variety of surfaces. To demonstrate the technology, the scientists printed a working heart-shapedbattery onto a cup, another onto a paper eyeglass and even one in the form of theletters "PRISS", all of which were capable of powering LEDs.
Conventional Li-on batteries come in set shapes and sizesbecause of the way they’re constructed. You need separator membranes to preventthe electrodes within the battery from coming into contact with each other. Andthe battery as a whole needs a robust case that doesn’t leak because of thecombustible liquid electrolyte within.
Theresearchers achieved their breakthrough by eliminating the need for traditionalseparator membranes. To do this, they created printable solid-stateelectrolytes that function as an ion-conducting medium.
"Thenew solid-state electrolytes are printable and also solidify after exposure toUV irradiation, eventually acting as an alternative separator membrane," Sang-YoungLee, a Professor at the Ulsan National Institute of Science and Technology(UNIST) in South Korea, told Gizmag.
Theprintable electrolyte in paste form, encases the electrodes, effectively actingas separator membrane. The electrodes themselves are composed of printable slurry.Once they’re both printed onto a surface they are cured by exposing them toultraviolet right. Additionally, the process removes the need for otherprocessing steps like injecting the liquid electrolyte and drying the solvent.
Theresulting printable solid-state battery (PRISS), can be printed in any arbitraryshape, and integrated seamlessly into curved objects or others with complexgeometries to create battery-embedded surfaces. For instance, the frame of amobile phone could itself be a battery.
Whentested, the performance of the printed battery was found to be on par withother flexible batteries. It was shown to have a 90 percent capacity retention after30 cycles, with no significant loss in charge or discharge capacities. Theresearchers plan to further improve the battery’s life and increase its energydensity by tweaking either the battery’s thickness or increasing theoverall printed area.
Currently,they are working on a new battery that can be printed directly onto clothes. They're also exploring new battery applications based on ink-jet and 3D printing technologies. The goal is to adapt the batteries to these technologies in such a way that they don’timpact the battery’s electrochemical properties.
"Weare trying to find unprecedented application fields that we have not yetencountered, most of which have difficulties using traditional batteries due toshape/design limitations," Lee told us. "One of most promising applicationfields is wearable electronics and the IOT (Internet of Things)."
Goingforward, they plan to make the rest of the battery components, such as currentcollectors and packaging materials, printable, enabling them to to createfully-printable batteries. They expect to launch shape-conformable totallyprintable PRISS batteries on the market within three to five years.
The team's paper describing the research was recently published in the journal Nano Letters.
