Battery & Electrification Technology - May/June 2024 - 24

have now, and then tune the battery to
bridge that gap. "
The ORNL team made Li-ion batteries
at the DOE Battery Manufacturing Facility
located at ORNL and ran them through
simulated climb stages of eVTOL aircrafts.
Scientists studied what happened
inside the battery during cycling - including
how much energy was rapidly
accessible during the demanding takeoff
phase - then tested the battery materials
afterward for corrosion and other chemical
or structural changes.
Systematic investigation linking actual
flight profiles to real-time physical battery
operation is rare. However, it is key groundwork
for developing new battery chemistries
to achieve safe flight performance.
The study incorporates testing of a
new ORNL-developed electrolyte - a
material through which electrodes exchange
ions - against the current
state-of-the art version used in Li-ion
batteries. Using the eVTOL mission
profiles, the ORNL electrolyte performed
better, retaining more capacity
during the most power-demanding
flight phases.
These results demonstrate the need
for diversifying how battery performance
is measured, Dixit said. " Your
battery is not just capacity at the end of
1,000 cycles. It's what's happening
within a cycle that tells you whether
your system is going to work or crash.
And the stakes are much higher here
because you're asking how safe it is to
go up in the air. This is a question we
don't know the answer to - yet. "
Members of the research team are
working on further improvements to the
electrolyte and other battery components
as they push the engineering
limits for battery power, payload, and
safety. Recent experiments involved collecting
real-world data from drone
flights over the lab's campus, then using
that information to develop a customized
profile of the load and draw on the
battery. Batteries made at ORNL were
then run through same cycles.
For more information, contact Heather
Duncan at duncansh@ornl.gov; 478718-9246.
Recyclable
'Water Batteries' That Won't Catch Fire
These batteries are well suited for large-scale applications, making them ideal for grid storage and
renewable energy integration - especially in terms of safety considerations.
RMIT, Melbourne, Australia
A
global team of researchers and
industry collaborators led by RMIT
University has invented recyclable
'water batteries' that won't catch fire
or explode.
Lithium-ion (Li-ion) energy storage
dominates the market due to its technological
maturity, but its suitability for
large-scale grid energy storage is limited
by safety concerns with the volatile materials
inside.
Lead researcher Distinguished Professor
Tianyi Ma said their batteries were at the
cutting edge of an emerging field of aqueous
energy storage devices, with breakthroughs
that significantly improve the
technology's performance and lifespan.
" What we design and manufacture are
called aqueous metal-ion batteries - or
we can call them water batteries, " said Ma,
from the School of Science.
The team uses water to replace organic
electrolytes, which enable the flow of
electric current between the positive and
negative terminals, meaning their batteries
can't start a fire or blow up unlike their
lithium-ion counterparts.
" Addressing end-of-life disposal challenges
that consumers, industry and gov24
The
team's water battery. (Image: Carelle Mulawa-Richards, RMIT University)
ernments globally face with current energy
storage technology, our batteries can
be safely disassembled and the materials
can be reused or recycled, " Ma said.
The simplicity of manufacturing processes
for their water batteries helped
make mass production feasible, he said.
" We use materials such as magnesium
and zinc that are abundant in nature,
inexpensive and less toxic than alternatives
used in other kinds of batteries,
which helps to lower manufacturing
Battery & Electrification Technology, May/June 2024

Battery & Electrification Technology - May/June 2024

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