In “The Super Supercapacitor,” a three-minute video
made by award-winning director Brian Golden Davis as an
entry into the 2012 Focus Forward Filmmaker Competition
that has now gone viral, Maher El-Kady, a Ph.D. candidate
in Professor Richard Kaner’s group, can be seen throwing a
handful of batteries into the “battery recycling bin,” in favor
of running everyday gadgets with a superior replacement—
the graphene supercapacitor. Graphene supercapacitors are
not only biodegradable, but are also able to charge and
discharge about 100 to 1000 times faster than the average
alkaline battery.
“Think of electric cars—the higher the capacity of the
battery, the farther you can go on a single charge, and the
higher the power, the faster you can run your car,” El-Kady
said. “This is what you want in the end, so we ended up
making a supercapacitor that has twice as much energy
density as commercial supercapacitors, and twenty times as
much power.”
The look of enthusiasm on El-Kady’s face when he says,
“Let’s talk about the future,” during an interview in Davis’
film, is parallel to the large number of potential applications
that have been linked to graphene supercapacitors, and to
greener energy prospects, including flexible technology and
improved hybrid vehicles. Although Kaner’s group is not
the first to build graphene supercapacitors, the team’s
scalable, environmentally friendly method is the most likely
to be commercially reproduced at this time. El-Kady was
one of two recipients of the 2012 Herbert Newby McCoy
Award, which honors the most significant research of the
year, for his research with Kaner that piqued the interest of
scientific journals, major news outlets, industry
professionals, and Davis, a film director with Los Angelesbased
company DocRiot.
Davis was one of about 100 people who contacted Kaner
following the March 2012 publication of an article in
Science, which described how graphite pieces are
transformed into graphite oxide, and, finally, into graphene,
using common LightScribe software designed for printing
text and images on CDs and DVDs, thus providing the
active material in supercapacitors. Davis read an article
about Kaner and El-Kady’s research and wished to turn their
discovery into a human interest film, entering it into the
Focus Forward competition, which offered up to $200,000
in prizes to the best cinematographic features showcasing
pioneering research capable of world change.
Motors on their hybrid cars, and everyone there basically expressed
that the key to hybrid vehicles was developing a new type of
battery,” Davis said. “Since battery technology develops very
slowly, I was super excited to read about Ric and Maher's work. I
didn't think, and don't think, even now, that people realize how big
a discovery a new energy storage device is.”
Although “The Super Supercapacitor” did not win the grand
prize in the competition, it ranked as the second most viewed film
of 95 finalists, was viewed by over 1 million people on Web sites
such as Reddit, Vimeo, YouTube, and Upworthy, and was
translated into Portuguese, serving as a promotional vehicle for
possibilities to come.
“It's not exactly ‘Gangnam Style’ numbers, but for a threeminute
documentary on a science subject, it should be considered
very successful,” Davis said.
Following publication of Kaner and El-Kady’s Science article, a
leading supercapacitor company also offered them a contract and
large donation to fund further research on supercapacitors, for
potential applications in transportation and energy grid storage.
“If you go to China, the new buses run on carbon-based
supercapacitors, and the reason they do that is a supercapacitor can
be charged and discharged relatively quickly,” Kaner said,
describing one such application. “While people are getting on and
off at a bus stop, you can charge your bus, and instead of having an
entire grid system, you just make the bus stop the charging station.
As long as there’s a bus stop every 10 to 20 miles, where the bus
can be recharged, it’s very happy to go along, and you need very
little infrastructure.”
El-Kady and Kaner have made several more breakthroughs over
the past year. Although their graphene supercapacitors can already
be charged 1000 times faster than batteries, El-Kady is working on
further boosting their capacity by making a supercapacitor-battery
hybrid that requires limited charging time to store a large amount
of power.
“If you specially design the supercapacitor-battery hybrid, you
can get the best attributes of the two,” El-Kady said.
They also developed mini versions of their supercapacitors,
called micro-supercapacitors, which is especially important since
the current portable electronics trend has spurred the
miniaturization of various technologies. Standard micro-fabrication
techniques have enabled on-chip micro-supercapacitors, but the
devices are expensive and are produced in a labor-intensive
process, thereby limiting their commercial applications. Using the
inexpensive LightScribe technique, El-Kady was able to make
more than 100 micro-supercapacitors on a single DVD disc in less
than 30 minutes, a terrific feat that may lead to direct power source
integration into computer processing chips. This research was
published in Nature Communications on February 12, 2013.
“It’s something that I believe is a very important step forward
towards the commercialization of graphene microsupercapacitors,”
El-Kady said.
Kaner said El-Kady’s educational background played a crucial
role in the discovery that graphene was ideal for building
supercapacitors, enabling him to take the lead in the continuation
of their research, and making him more than deserving of the
McCoy award.
“This would not have come about unless Maher came with his
master’s degree in electrochemistry, and, literally, after measuring
the speed of electron transfer on graphene, realized that this was a
good application,” Kaner said. “I have some background in
electrochemistry–my Ph.D. was on making the first batteries out of
conducting polymers–but I hadn’t actually done much
electrochemistry since I’d been here, so it was refreshing to see
him come, and he definitely deserves whatever accolades come his
way.”
El-Kady has always pushed himself to succeed. An almost
middle child of a family of nine children, five boys and four girls,
El-Kady grew up in Egypt and was strongly encouraged to pursue
an education by his parents, both of whom lacked the opportunities
available to him.
“My mother didn’t get an education and my father didn’t get an
education either, although he later learned how to read and write
some words,” El-Kady said. “They made sacrifices so I could
pursue what I love to do. I would like to take this opportunity to
remember my father who passed away when I was about to join
UCLA. Without his help, I wouldn’t be here today. I would also
like to thank my mother, who gave me a lot of support during my
school studies to do something, to be an effective member of
society. Even though she didn’t know exactly what that could be,
she was giving me the support to get a nice education, because then
I would eventually know my way and do better than they did.”
El-Kady said science became a career path at an early age, as he
has looked up to Ahmed Zewail, the 1999 Nobel Laureate in
chemistry, since he was 12, and was first fascinated by his sixth to
eighth grade science teacher’s lab experiments. Fulfilling his
parents’ aspirations, he received his bachelor’s of science in
chemistry from Cairo University, in 2004, ranking as the top
student in his department and gaining a position as a professor at
Cairo University, to commence upon the completion of his
doctorate. His collaboration with Kaner, who he admired for his
work in conducting polymers, began while he was working on his
master’s thesis, as his committee selected Kaner as an external
reviewer. Soon after completing his master’s in physical chemistry,
in 2009, El-Kady received a graduate fellowship to earn his
doctorate in the United States, choosing to join Kaner’s group. He
intended to study conducting polymers, but became interested in
graphene, a newer material discovered in 2004.
“Ric started at the time when conducting polymers were
actually the golden material, but, after 40 years, most of their
interesting applications had been done already,” El-Kady said.
“Current research has taught us that graphene is the new star
material of our time. Measurements showed that graphene is one of
the strongest materials known to man, conducts electricity better
than copper, and is completely flexible. Most interestingly,
graphene has extrememly high surface area. For example, you can
cover an entire football field with less than one gram of graphene.
These interesting properties suggested that graphene could be used
for a variety of applications. However, the question was if we could
make a useful device out of graphene, and before that, we needed
to ask a more important question—could we make graphene using
an inexpensive and scalable process?”
Kaner originally set out to find a scalable method for making
graphene, as the one made famous by 2010 Nobel Laureates Andre
Geim and Konstantin Novoselov was difficult
to reproduce. Geim and Novoselov’s method used tape to peel
layers from a piece of graphite until one layer, graphene, resulted.
Kaner’s method instead involved chemical exfoliation of graphene
sheets from graphite oxide, documented in the most-cited article in
Nature Nanotechnology, and El-Kady said he wanted to take this
finding to the next step.
“My goal at that time was to make a graphene supercapacitor
that could store more energy than commercially available
supercapacitors and also provide more power,” El-Kady said.
However, researchers have faced the common challenge that
the single layers of graphene stick together, reducing its surface
area. To produce graphene sheets that remained separate once
combined into supercapacitors, El-Kady, Veronica Strong, a
former graduate student, Sergey Dubin, another Ph.D. candidate in
Kaner’s group, and Kaner decided to use a laser to convert
graphite oxide into graphene, settling on the laser inside a
LightScribe drive, because it was inexpensive and accessible. A
few years earlier, they discovered that graphite oxide could convert
into graphene when exposed to intense light, and the LightScribe
method provided control over the speedy conversion process.
“We looked at the microscopic structure of graphene and found
that the graphene sheets were separated nicely and were highly
conductive,” El-Kady said. “So I thought this was the material that
we were after for making an ideal battery or supercapacitor.”
El-Kady hurried to build a supercapacitor, running to Radio
Shack to buy several LEDs, ordering electrolytes, and using 10-
year-old electrolytes found in the lab for the time being. Once the
supercapacitor was ready, El-Kady charged it and attached it to an
LED. “Amazingly enough, it worked,” El-Kady said. “It lit up the
LED for several minutes, and I was so excited about it, so I called
Veronica (Strong) and said, ‘Here is the interesting application that
we’re after.’”
“I was convinced that it would be very important, because
you’re always wondering whether scientists can discover a
wonderful battery that you can have in your cell phone for several
days instead of one,” El-Kady added. “The second thing is that we
can make it completely flexible.”
Flexible technology suitable for roll-up displays has recently
gained popularity among researchers. While batteries could break
and lose conductivity if bent, graphene supercapacitors can be bent
in several directions and maintain conductivity, paving the way for
applications in military equipment and flat screen, bendable
displays, such as the Samsung Youm Flexible OLED Displays,
which were presented at the 2013 Consumer Electronics Show
(CES).
Kaner said El-Kady’s discovery prompted him to recall his own
days as a student, when his graduate advisor, Nobel Laureate Alan
MacDiarmid, would make him demonstrate his findings before
trusting that he had produced significant results.
“He didn’t believe anything until he could actually see or touch
it, so it just reminded me of when my advisor used to say, ‘Ok, you
say this battery works? I want to see how it works,’” Kaner said.
After graduating in June, El-Kady said he plans to return to
Egypt in time for Eid al-Fitr, the festival that follows Ramadan, to
celebrate the end of a month of fasting with
his family. Determined to apply his valuable
education to instruction at Cairo University, El-
Kady also said he intended to teach his students
various lab demonstrations. He even used his
McCoy award to stock up on textbooks, either
unavailable or too expensive in Egypt, which he
said would provide necessary updates to the
current curriculum. El-Kady will teach in Egypt
for a year, before attempting to secure a postdoctoral
position in the United States.
Although he is still interested in graphene, he
said he plans on finding applications for more
recent discoveries, such as water splitting, which
may lead to clean energy sources. He met Nobel
Laureate Sir Harold Kroto at the Lindau Nobel
Laureates Meeting in Germany, in 2009, and,
while at the meeting, was featured in another
short film, titled “Nanotechnology: Use and
Misuse,” in which he discussed similar research
interests with Kroto. He walked away with a
lesson he continues to utilize today–embrace the
scientific method, leaving others’ opinions
behind.
“(Kroto) liked the dogma in science that we
should not be affected by previous thoughts about
things,” El-Kady said. “I think that’s very
important. It was inspiring, because scientists had
a dogma about graphene; they thought that any
two-dimensional crystal should not exist in
nature, and that’s actually why graphene was
discovered very late. People considered it an
unstable form of carbon that shouldn't exist, but
the guys who won the Nobel Prize put an end to
these thoughts–graphene is stable–and it was like
a shock to the scientific community.”
Similarily, Kaner has urged his research group
to move forward in innovation, rather than finding
one solution to a problem and considering it
solved, something that El-Kady said he wished to
instill in his students.
“You can make a high surface material, and
stop and say, ‘Well this is a high surface material,
and it will make a very nice battery,’ but then you
need to prove that you made this material, and
that it will perform better than others in the
market or in previous literature,” El-Kady said.
“So that’s why Ric is always encouraging us to
find applications; we’re always after applications
that society is interested in, and if you talk about
them, they’ll get excited.”
The photo featured on p. 1 is a still from Brian
Golden Davis’ “The Super Supercapacitor.” The
short film can be viewed at: http://vimeo.com/
focusforwardfilms/semifinalists/51873011.
Commentaires