between 500 and 900 degrees Celsius in a furnace
under inert atmosphere in the presence or absence of
a transition metal salt catalyst."
The resulting material is then processed into the anodes.
"The process is inexpensive, environmentally benign
and potentially practical for large-scale manufacturing,"
Etacheri said. "Microscopic and spectroscopic analyses
proved the microstructures and morphologies
responsible for superior electrochemical performances
are preserved after many charge/discharge cycles."
Commercial anode particles are about 10 times thicker
than the new anodes and have higher electrical
resistance, which increase charging time.
"In our case, if we are lithiating this material during the
charging of a battery, it has to travel only one micrometer
distance, so you can charge and discharge a battery faster
than your commercially available material," Pol said.
Because the sheets are thin and porous, they allow
better contact with the liquid electrolyte in batteries.
"These electrodes exhibited notably higher lithium-ion
storage performance compared to the commercially
available graphite anodes," he said.
Packing peanut–derived carbon anodes demonstrated
a maximum specific capacity of 420 mAh/g (milliamp
hours per gram), which is higher than the theoretical
capacity of graphite (372 mAh/g), Etacheri said.
"Long-term electrochemical performance of these
carbon electrodes is very stable," he said. "We cycled
it 300 times without significant capacity loss. These
carbonaceous electrodes are also promising for
rechargeable sodium-ion batteries. Future work will
include steps to potentially improve performance by
further activation to increase the surface area and pore
size to improve the electrochemical performance."
A paper about this research was published in
Environmental Science and Technology in June 2015.
Dr. Pol works in his laboratory with graduate student Arthur Dysart.
Research conducted by a team led by Professor Pol
was selected for an R&D Top 100 Award. His "carbon
microspheres" are created from waste plastics and
are an environmentally friendly product. They were
selected as one of the most technologically signifcant
new products for 2015. The R&D 100 awards have
been called the "Oscars of invention."
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