Livermore researchers have identified electrical charge-induced changes in the
structure and bonding of graphitic carbon electrodes that may one day affect
the way energy is stored. The research could lead to an improvement in the
capacity and efficiency of electrical energy storage systems, such as batteries
and super capacitors, needed to meet the burgeoning demands of consumer,
industrial and green technologies.
Livermore research has opened a new window toward more efficient
electrochemical energy storage systems. Credit: Ryan Chen/LLNL
technology requires energy storage systems to have much larger storage
capability, rapid charge/discharge cycling and improved endurance. Progress in
these areas demands a more complete understanding of energy storage processes
from atomic through micron-length scales. Because these complex processes can
change significantly as the system is charged and discharged, researchers have
increasingly focused on how to look inside an operating energy storage system.
While computational approaches have advanced over the last few decades, the
development of experimental approaches has been very challenging, particularly
for studying the light elements that are prevalent in energy storage materials.
work by an LLNL-led team developed a new X-ray adsorption spectroscopy
capability that is tightly coupled with a modeling effort to provide key
information about how the structure and bonding of graphitic carbon super capacitor
electrodes are affected by polarization of the electrode – electrolyte
interfaces during charging. Graphitic super capacitors are ideal model systems
to probe interfacial phenomena because they are relatively chemically stable,
extensively characterized experimentally and theoretically and are interesting
technologically. The team used its recently developed 3D nanographene (3D-NG)
bulk electrode material as a model graphitic material.
newly developed X-ray adsorption spectroscopy capability allowed us to detect
the complex, electric-field induced changes in electronic structure that
graphene-based super capacitor electrodes undergo during operation. Analysis of
these changes provided information on how the structure and bonding of the
electrodes evolve during charging and discharging,” said Jonathan Lee, an
LLNL scientist and corresponding author of a paper scheduled to appear as the
cover article of the March 4 edition of the journal, Advanced Materials.
“The integration of unique modeling capabilities for studying the charged
electrode-electrolyte interface played a crucial role in our interpretation of
the experimental data.” (Source: Phys.org)