Researchers
at university of Sidney have created a new battery cell that will allow
renewable energy to be stored on a rainy day.
Currently,
any renewable energy supply needs backup for the times when ‘the wind doesn’t
blow and sun doesn’t shine’. That back-up might be environmentally unfriendly,
such as carbon dioxide generating gas turbines or oil and coalfired power
plants.
“Batteries
are a natural solution,” says Professor Thomas Maschmeyer. “They are a near
instantaneous buffer, and they could enable much more renewable power to be
deployed into the grid when needed.”
What Maschmeyer
is talking about here isn’t traditional solid state batteries, which can’t work
on the scale that’s needed, cheaply enough. He’s talking about his new battery
concept built around existing zinc bromine chemistry. Though this chemistry
also presented a major problem.
“Elemental
bromine is dangerous,” he says. “You really don’t want to inhale its vapours,
and if you put your finger in bromine liquid, it will dissolve your skin.
However, this chemical translates powerfully into batteries, which is very attractive.”
Maschmeyer
could have looked for a new battery chemistry to side-step the problem.
Instead, he thought differently about the zinc-bromine battery and realised
that it could still hold the answer.
Innovative
energy solution
Zinc-bromine
batteries are what’s called flow batteries and hold their energy in electrolyte
solutions, unlike the more familiar solid state batteries which use metal
electrodes. This often makes flow batteries non-portable, inflexible and
costly, so they’re mostly used for niche applications like powering army bases.
Maschmeyer
found a way to make flow batteries more like solid state batteries by working
at the nanoscale.
“We’ve
been able to encapsulate that bromine in a nano-gel in such a way that it is
still chemically aggressive,” he says. “But now I can put my finger into the
gel and I just have to rinse it off to remain perfectly fine – we tamed the
tiger.”
Maschmeyer
has created a single, versatile, battery cell that can be assembled into
modules in the sizes needed; small for use in solar street lights, or very
large for powering communities.
To take
the battery idea forward, Gelion Technologies was formed in 2015 as a spin-off
from the University of Sydney, with of the supporting work still happening in
the School of Chemistry.
The
technology is now in the commercial prototype phase with demonstration products
being released throughout 2019 and with mass-production expected to start in
2020/21.
Potential
impact
An example
of how this technology will change things is in the building industry.
Maschmeyer’s zinc-bromine batteries have fire retardant qualities, which
developers are already looking at integrating into the fabric of buildings. By
connecting them to solar cells on the roof, residential, commercial and
industrial buildings would become more energy independent.
This will
take renewables to the next level and revolutionise how we all consume energy.
Maschmeyer
himself, has a further ambition for his technology, “By pairing a compact solar
cell with a zinc-bromine battery, millions of people who now don’t have access
to electricity at all could live different lives. For me, that’s very
motivating.”