Page 57 - Plastics News February 2019

teChnoLogy

Better batteries: The energy implications of organic radical polymers

esearchers are one step closer to realizing their goal radical polymer." The results of the EQCM-D analysis led
Rof creating a battery made entirely of polymers, which to somewhat unexpected results. Before this research the
has the potential to charge and discharge much faster than consensus was that only anions were transported in this
traditional batteries. Texas A&M University professor Dr. process. However, the results show that lithium ions are
Jodie L. Lutkenhaus is one step closer to realizing her goal transported as well.
of creating a battery made entirely of polymers, which
has the potential to charge and discharge much faster Antireflection Coating Makes
than traditional
ba t t e ri e s. Transparent Plastics Virtually
Lutkenhaus, an Invisible
associate professor
in the Artie McFerrin enn State researchers have developed a new
Depar tment Pantireflection (AR) coating that makes transparent
of Ch e mical plastics virtually invisible.Antireflection coatings are
Engineering, has primarily used to reduce glare on eyeglasses, computer
detailed her most monitors and the display of smartphones when
recent findings on outdoors.According to Penn State associate professor
these polymers in a paper in Nature Materials. A major Chris Giebink, his team’s AR discovery was an accidental
hurdle to creating a metal-free, 100-percent polymer one and came about when they were trying to make
battery is finding a polymer that is electrochemically higher-efficiency solar panels.“Our approach involved
active -- meaning it has to be able to store and exchange concentrating light onto small, high-efficiency solar
electrons. Lutkenhaus, along with a team of researchers cells using plastic lenses, and we needed to minimize
including doctoral candidate Shaoyang Wang, think that their reflection loss.”The researchers were in need of
the organic radical polymers will do the trick. Owing to an antireflection coating that worked well over the
their chemical structure, organic radical polymers are entire solar spectrum
very stable and reactive. They have a single electron on and at multiple angles
as the sun crossed the
the radical group, and this unpaired electron allows rapid sky.They also needed
charge transfer in these polymers during redox reactions.
a coating that could
According to Lutkenhaus, the main appeal of this class stand up to weather
of polymer lies in the speed of the reaction. "These over long periods of
polymers are very promising for batteries because they time outdoors “We would have liked to find an off-
can charge and discharge way faster than any common the-shelf solution, but there wasn’t one that met our
battery in a phone or similar device. This rapid charging performance requirements,” said Giebink. “So, we
could dramatically change the way electric vehicles are started looking for our own solution.”
used today."The redox-active properties of organic radical Giebink and his team were successful in creating a new
polymers have been known for some time. However, prior process to bridge the gap between Teflon and air. They
to this research the exact mechanism by which electrons used a sacrificial molecule to create nanoscale pores
and ions are transported through the polymer had not been in evaporated Teflon, thereby creating a graded index
described. Lutkenhaus and her team were able to capture Teflon-air film that fools light into seeing a smooth
incredibly detailed measurements using a specialized transition from 1 to 1.5, eliminating essentially all
device, an electrochemical quartz crystal microbalance reflections. Since the technology is compatible with
with dissipation monitoring (EQCM-D). The use of an current manufacturing techniques, Giebink believes
EQCM-D is actually quite simple, The device is so sensitive their coating technology could be scaled up and used
that we can measure ions going in and out of the organic for a variety of applications.

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57 Februar y 2019 Plastics News