Upcycling technique turns plastic bottles into supercapacitor material
Supercapacitors hold incredible potential when it comes to energy storage, with an ability to charge and discharge almost instantly being one of their major selling points. Were key components for these next-generation devices to come from sustainable sources that would only add to the appeal, and scientists at the University of California, Riverside (UCR) are offering up this possibility in the form of a nanomaterial made from upcycled plastic waste.
The breakthrough comes from a team of engineers led by UCR’s Cengiz Ozkan, who for years has been investigating new nanoscale materials that can help make supercapacitors viable options for energy storage. Previously, Ozkan and her colleagues have made promising advances involving everything from graphene to glass bottles, but their latest discovery centers on one of the largest environmental headaches we face in plastic waste.
The team started with pieces of plastic bottles made from polyethylene terephthalate plastics, or PET. These were dissolved in a solvent and turned into microscopic fibers using a technique known as electrospinning, with the fibers then converted into carbon in a furnace.
The material was then mixed with a binder and conductive agent before being incorporated into a double-layer capacitor in a coin-cell-like shape. Testing of the new electrode material in this configuration showed that it functioned as a perfectly capable component of a supercapacitor.
“At UCR, we have taken the first steps toward recycling plastic waste into a rechargeable energy storage device,” says doctoral student and first author Arash Mirjalili. “We believe that this work has environmental and economic advantages and our approach can present opportunities for future research and development.”
While supercapacitors charge faster than lithium batteries, they don’t store nearly as much energy. So while they could allow for electric vehicles that charge in minutes rather than hours, or phones or laptops that do the same, there will still be a place for the energy storage architecture widely used today. But the team believes that the approach used here could be adapted to improve the performance of these lithium batteries, too.
"The upcycling of PET plastic waste for energy storage applications could be considered the holy grail for green manufacturing of electrode materials from sustainable waste sources,” says Cengiz Ozkan. “This demonstration of a new class of electrodes in the making of supercapacitors will be followed by a new generation of Li-ion batteries in the future, so stay tuned."
The research was published in the journal Energy Storage.