Tech Briefs Magazine - September 2022 - 42

Power & Energy
Energy Storage Materials Make Batteries More Efficient
and Heat-Resistant
New polymer electrolytes are used as electrolytes in redox flow batteries.
Friedrich Schiller University, Jena, Germany
R
esearchers have developed new polymer
electrolytes for redox flow batteries
that are flexible, efficient, and environmentally
friendly.
In redox flow batteries, the energy-storing
components are dissolved in a solvent,
and can therefore, be stored at a decentralized
location, which allows the battery
to be scaled as re quired, from a few milliliters
to several cubic meters of electrolyte
solution.
Thanks to this flexibility, redox flow
batteries could become an important
means of energy storage; however, until
now, they suffered from two weaknesses
that have prevented their widespread
use. The first is the frequent use of
environ mentally hazardous and toxic
heavy metal salts, such as vanadium dissolved
in sul furic acid, as electrolytes.
The other problem is the restriction of
the batteries to a maxi mum working
temperature of 40 °C, which necessitates
the use of an elabo rate cooling system.
With the help of the new material, these
two problems were solved.
The new type of polymer is soluble in
water - which makes it suitable for use in
an aqueous electrolyte - and that contains
iron, which provides the ability to
store elec tricity. At the same time, the polymer
can cope with a significantly higher
temperature of up to 60 °C, so that the additional
expense for sensitive tem pe rature
management is eliminated. In addition,
during their tests with the new system, the
researchers discovered that it also works
more efficiently than its predecessors.
This means that electricity can be stored
in a non-hazardous, water-based solution
that is then stored temporarily in tanks
and the electricity in the battery can be
used again the next day without significant
losses or additional effort. Systems of this
kind can also be used in warmer re gions.
For more information, contact Ulrich
S. Schubert, Prof. Dr, at ulrich.schubert@
uni-jena.de; +49 3641-9-48560.
Room-Temperature Liquid-Metal Battery
The battery promises more power than lithium-ion batteries and can charge and deliver
energy several times faster.
University of Texas, Austin, TX
R
esearchers have built a new
type of battery that combines
the benefits of existing options
while eliminating their key shortcomings
and saving energy. Most
batteries are composed of either
solid-state electrodes, such as lithium-ion
batteries for portable
electronics, or liquid-state electrodes
including those for smart
grids. The researchers have created
a " room-temperature all-liquid-metal
battery, " which includes
the best of both worlds of liquidand
solid-state batteries.
Solid-state batteries feature
significant capacity for energy
storage
but they
typically encounter
numerous problems
that cause them to degrade over
time and become less efficient.
Liquid-state batteries can deliver energy
more efficiently without the long-term
decay of sold-state devices; however,
they either fall short on high energy demands
or require significant resources
to constantly heat the electrodes and
keep them molten.
The metallic electrodes in the new battery
can remain liquefied at a temperature
42
The battery includes a sodium-potassium alloy as the anode and a
gallium-based alloy as the cathode.
of 20 °C (68 °F) - a major change because
current liquid-metal batteries must
be kept at temperatures above 240 °C.
The battery includes a sodium-potassium
alloy as the anode and a gallium-based
alloy as the cathode. It may
be possible to create a battery with
even lower melting points using different
materials.
www.techbriefs.com
20 °C
68 °F
Na-K liquid
metal anode
Organic electrolyte
Ga-based liquid
metal cathode
Because of the liquid components,
the battery can be scaled up
or down easily, depending on the
power needed -the bigger the
battery, the more power it can deliver.
That flexibility allows these
batteries to potentially power everything
from smartphones and
wearable devices to the infrastructure
underpinning the movement
toward renewable energy.
Many of the elements that constitute
the backbone of the new
battery are more abundant than
some of the key materials in traditional
batteries, making them potentially
easier and less expensive
to produce on a large scale; however,
gallium remains an expensive
material. Finding alternative
materials that can deliver the
same performance while reducing the
cost of production remains a key challenge.
The next step to in creasing the
power of the room-temperature battery
comes in improving the electrolytes -
the components that allow the electrical
charge to flow through the battery.
For more information, contact Nat
Levy at nat.levy@utexas.edu.
Tech Briefs, September 2022
https://technology.nasa.gov/patent/MSC-TOPS-98 http://www.techbriefs.com
Tech Briefs Magazine - September 2022

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