It's getting pretty crowded in the energy storage sector these days don't you think?
It seems like almost every other day an article or peer-reviewed paper drops into my news feed about
a breakthrough game changer that's apparently set to revolutionize the industry. Believe it
or not I do try to filter out the inventions that are, you know, slightly more ambitious
and only bring you the ones that are either already on the market or that are sufficiently far
along the R&D and funding road they do at least look like they have a decent chance of finding
their way into a production facility at some point in the near future. And as several of you have
suggested in recent months I will try to revisit some of those innovations in upcoming videos
to see how they're actually performing in the real world. One of the more promising technologies
we've looked at on the channel is flow batteries. They're cheap, safe, reliable and scalable,
and they will no doubt be an important addition to stationary utility scale energy storage in
certain applications. But they're also quite big and cumbersome and have all sorts of intricate
mechanical components that require highly specialized maintenance, plus they need auxiliary
power to get them going in the first place which is a drain on their overall efficiency requiring a
secondary backup system for the battery itself. So what if we could keep all the advantages of flow
batteries and get rid of the disadvantages? Well yes you've guessed it, someone has found a way.
And I'm not talking about a group of laboratory researchers here. This one's a publicly listed
company with multi-million dollar funding and a global partner for mass production. So is it
time to break out the overused superlative cliches once again? Well let's take a look and find out.
Hello and welcome to Just Have a Think. We've talked about flow batteries a couple of times
on the channel. They are unapologetically robust and industrial in nature. You basically fill two
containers with an electrolyte solution, which can be something like vanadium, or in this example
zinc bromide. The electrolytes are pumped into a central stack where the zinc gets deposited on one
electrode and the bromide converts to bromine on the other electrode. That process consumes
electrons and stores energy. To discharge the system you pump the depleted electrolyte
back through the stack to reverse the process and liberate the electrons to flow out into a circuit.
If you want more energy you just add bigger tanks. Unlike normal batteries you can discharge these
things right down to zero without causing any damage and they'll keep charging and discharging
for thousands of cycles with almost negligible loss of capacity. So there's a lot to like,
whether you're a domestic user or a remote micro grid community or a full-scale utility
grid operator. The downside is the complexity of pumps, pipes, valves and manifolds required
to move the liquids around the system, all of which, as I mentioned earlier, need power to run.
And unlike lead acid or lithium-ion batteries when the battery is fully discharged that power
has to come from an external source to get the process started, a bit like the cranking handle
on an old Model T Ford. All of that represents a drag on the overall efficiency of the system.
So who's this publicly listed business that claims to have ironed out all the wrinkles then?
Well, they're called Gelion, which is a name derived unsurprisingly from the words gel and ion,
which kind of gives you a clue about the technology they've developed. The company was
founded by a chemist called Professor Thomas Maschmeyer from the University of Sydney in
Australia, and it's now listed on the AIM market in the London stock exchange. I caught up with
Professor Maschmeyer via a zoom call recently and he explained how his innovation works.
In contrast to existing flow batteries the zinc bromide gel battery looks very familiar
indeed. In fact the housing is pretty much exactly the same as a lead acid battery,
which is something we'll touch on later. If you open the casing up you find sets of negative
and positive electrodes with membranes to separate them and prevent short circuits,
just like a standard battery. The electrolyte is largely present as a gel rather than a liquid,
hence the gel part of the Gelion name. It's a water-based material containing various additives
and salts including zinc bromide. Just like the flow battery, during charging zinc ions migrate to
the negative electrode where they accept electrons and get reduced to zinc metal. The bromide ions
flow across to the positive electrode where they lose electrons to become bromine. And then when
the battery is discharged the process is reversed, allowing electrons to flow out into a circuit
and provide electrical power. Having the gel electrolyte inside the battery with the electrodes
eliminates the need for a pumping system and that means the Gelion battery can start
charging from zero without the need for an external power source to run any pumps.
Professor Maschmeyer also pointed out that using a gel rather than a liquid
keeps the bromine really well distributed inside the battery which greatly reduces unwanted
processes like dendrite formation, bromine stratification, hydrogen formation and ph drift.
Lead acid batteries are better than lithium-ion batteries at coping with high operating
temperatures but once you get above about 40 degrees Celsius both battery types generally
require cooling systems to prevent battery degradation or even the risk of fire. The
Gelion battery can operate right up to 50 degrees Celsius without the need for cooling, which is
handy, especially in certain standalone working environments that might not be as well regulated
or managed as a utility scale grid system. Those standalone facilities might experience
over charging or over discharging which can cause big problems for existing battery technology.
The Gelion battery can be discharged to zero volts and left in storage for long periods with
no adverse risks or consequences and no impact on performance or longevity. And it's much more
tolerant of overcharging too. Not least because, for reasons of physics that are outside the scope
of this video, the homogeneous distribution of the bromine and bromide within the gel electrolyte
acts as a fire retardant. Lead acid batteries have, of course, been around for a very long
time now and competition from lithium ion and other energy storage technologies mean they're
on something of a long-term downward trajectory. But they're still pretty ubiquitous all over the
world and the industry is still worth about 45 billion a year. The Gelion battery has been
specifically designed and configured to fit snugly into the production cycle of lead acid battery
factories. Offering a new technology to all those very well established manufacturing facilities
is a very smart move. There are something like 22 steps to make a Gelion battery, and 18 of
them are taken directly from lead acid battery manufacturing, leaving only four unique steps to
incorporate. They can even package their product in the same casings as lead acid batteries. That's
a huge advantage in terms of market entry that's not available to technologies like redox flow
batteries which require new production lines and facilities to be built and financed from scratch.
Professor Maschmeyer put some numbers to that assertion. He told me that to retrofit an existing
one gigawatt hour lead acid battery facility to start making one gigawatt hour of zinc bromide gel
batteries would cost around 16 million US dollars. By comparison to set up a lithium-ion battery
facility from scratch with the same production capacity costs about 130 million US dollars.
And the Gelion advantages flow right through to the recycling stages as well, which is a crucial
consideration as we move towards the circular economy of the future. Lead acid batteries are
already very widely recycled at fairly low cost, but they do contain lots of nasty stuff like
toxic lead and corrosive sulfuric acid which are hazardous to the environment if they leak out.
Lithium-ion battery recycling is only in the early stages of development and it's a
very complex process to separate out all the materials. It will get much better over time
of course no doubt but right now it's just not economically viable without significant subsidy.
The Gelion battery can be recycled in existing lead acid battery recycling facilities and at a
similar low cost but with far fewer environmental risks because the discharge cells don't contain
any toxic metals or strong acids. Now a zinc bromide gel battery is never going to be as
light as a lithium-ion battery, just by nature of the different materials and chemistry types used.
Gelion is currently aiming for specific energy densities around 50 to 60 watt hours
per kilogram which is significantly lower than the 200 or so that can be achieved with lithium
ion. So it's probably fair to say they're not about to completely eliminate the competition,
but there's no doubt there will be many applications where Gelion's advantages will make
them a more attractive option. Remote off-grid areas in developing nations are a perfect example,
and Gelion are already working on a 100 megawatt hour project in Papua New Guinea
to bring energy independence and new income streams to local people there. But the chemistry
of the Gelion battery means it can work just as well as a replacement for gas peaker plants to
provide peak time stability on utility scale grid systems. And with a discharge time sweet spot of
between four and eight hours it's a great solution for shifting renewable energy from the time it's
generated to the time it's needed, helping to move solar and wind closer to that magic goal of
base load generation. The batteries themselves will be formatted to run at 12 or 48 volts
and of course they can be combined together in series in parallel to achieve whatever voltage
and current is required. Gelion are currently building a pilot production line in partnership
with a Sydney based manufacturer called Battery Energy and they've got a second partnership
with a very large global scale battery producer in India to get mass production up and running there.
As well as all that, earlier this year Gelion was selected by one of Europe's
largest sustainable energy companies, Acciona Energy, to supply working models
so that Acciona can assess how to integrate them into their existing production capacity.
So there we are then folks. Another brave innovator entering the increasingly crowded
energy storage market. As always, only time will tell how successful this
particular technology proves to be, but the combination of low-cost abundant materials,
a well-established manufacturing base, and a very robust safe and reliable architecture means
there's a good chance Gelion could carve out a lucrative niche in our sustainable energy future.
No doubt you've got your own views on these sorts of technologies, so as always feel free to jump
down to the comments section below to leave your thoughts there. That's it for this week though.
I'm taking a short break now so there'll be no video next week, but I'll be back
on Sunday the 19th of June with more news and views from the world of climate change
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