Battery & Electrification Technology - May/June 2024 - 23

collaboration between JAIST and Maruzen
Petrochemical Company Ltd., along with
the inclusion of additional battery production
expertise from the company, may further
accelerate the process toward real-life
applications. Patents for this technology
have been submitted both domestically
(Japan) and internationally as a joint application
by JAIST and Maruzen Petrochemical
Company Ltd.
" An industrially feasible, high-performing
binder like this will aid in the development
of technology for highly durable
and high-energy-density batteries. This
will result in the wider adoption of EVs
worldwide without concerns about performance
degradation over a longer period.
These materials can also be applicable
to a variety of electric vehicles such
as trains, ships, aircraft, etc., in the future, "
envisions Matsumi.
For more information, contact Akiko
Tsumura at kenkyu-koho@ynu.ac.jp; +81453-393-213.
Testing
the Engineering Limits for eVTOL Battery
Power
Unlike EV batteries, eVTOL batteries need varying amounts of power for flight stages, with some phases
requiring high bursts of power.
Oak Ridge National Laboratory, Oak Ridge, TN
R
esearchers at the Department of
Energy's Oak Ridge National
Laboratory are taking cleaner transportation
to the skies by creating and
evaluating new batteries for airborne
electric vehicles that take off and land
vertically.
These aircraft, commonly called
eVTOLs, range from delivery drones to
urban air taxis. They are designed to rise
into the air like a helicopter and fly
using wing-borne lift like an airplane.
Compared with helicopters, eVTOLs
generally use more rotors spinning at a
lower speed, making them both safer
and quieter.
The airborne EV's aren't just flying
cars, and ORNL researchers conclude
that eVTOL batteries can't just be
adapted from electric car batteries. So
far that has been the dominant approach
to the technology, which is
mostly in the modeling stage. ORNL researchers
took a different tack by evaluating
how lithium-ion batteries fare
under extremely high power draw.
" The eVTOL program presents a
unique opportunity for creating a brand
new type of battery with very different
requirements and capabilities than
what we have seen before, " said Ilias
Belharouak, an ORNL Corporate Fellow
who guides the research.
Researchers are developing new energy-dense
materials, learning how these
materials degrade under extreme conditions,
and developing battery control sysThe
operating phases of an eVTOL need varying amounts of power; some require the battery
to discharge high amounts of current rapidly, reducing the distance the vehicle can travel before
its battery must be recharged. (Image: Andy Sproles/ORNL, U.S. Dept. of Energy)
tems. " This requires us to answer questions
about the interplay of battery safety, cycle
life, and stability at high temperatures,
while balancing the need for short bursts of
high power with energy reserves for longer-range
flight, " Belharouak said.
The first major takeaway from an extensive
eVTOL research project underway
at ORNL is that the power and
performance demands for eVTOL batteries
can significantly reduce their longevity
and durability.
Unlike electric vehicle batteries,
which typically drain at a steady rate,
Battery & Electrification Technology, May/June 2024
eVTOL batteries need varying amounts
of power for flight stages such as
climbing, hovering and descent, with
some phases requiring high bursts of
power.
" Now we know more about what is
required of the eVTOL battery, we'll
need to engineer systems differently to
achieve that, " said ORNL lead researcher
Marm Dixit. " Our focus is fundamental:
What happens to the materials under
these specific loads and operating conditions?
We are trying to figure out the
limitations of the battery chemistry we
23
TAKE OFF
CLIMB
CRUISE
DESCENT
Capacity
Power
Capacity
Capacity
Power
Capacity
Power
Power

Battery & Electrification Technology - May/June 2024

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