For the last century, we’ve produced the energy we need by burning things.
Whether it be coal in power plants, or gasoline in our cars, the energy we’ve needed has
come from fossil fuels.
Not too unlike our cave dwelling ancestors who burned wood for warmth.
But if we are to progressto a cleaner civilized future in the next century, we need to look
to renewable forms of energy.
And because we can’t control when the sun shines or wind blows, that means storing that
energy for when we need it, and that of course means batteries.
It’s why I talk about batteries all the time on this channel, and why you’re in
luck because today there’s some breakthrough researching happening into graphene batteries,
that you guessed it, can be a “game changer”.
Now if you’re thinking, didn’t you do a video on graphene, yes I did, but that was
a graphene supercapacitor, an electrostatic form of energy storage, as opposed to chemical
energy storage like the battery in your smartphone or EV.
So how does Graphene change the game, what sorts of benefits might it bring, and what
exactly is graphene?
Let’s dive in.
I believe batteries and battery research are one of the most important areas of science
this decade.
And graphene has long been heralded as a miracle material that is stronger than steel, lighter
than titanium, and better at transferring electricity and heat than copper.
Graphene is a variation of carbon — but more specifically, a variation of graphite
— that stuff inside your pencils.
But unlike typical graphite, or other forms of carbon, graphene is only one atom thick
— which basically means its a 2 dimensional material.
Why does this matter?
Well, materials are electrically conductive because electrons can freely move across their
surface.
So the more surface area a material has, the more electrons it can facilitate.
If you unfolded just one gram of graphene, it would have a surface area of nearly 2700
square meters — roughly the size of 10 tennis courts!
Graphene also has a tightly-bonded, hexagonal, honeycomb-like pattern.
This shape gives it all sorts of unique properties because those electrons have so much space
to move around.
Not only is graphene insanely good and conducting both heat and electricity, it’s also insanely
strong — with a tensile strength four times that of steel!
Yet despite that strength, it still remains incredibly flexible.
These properties have elevated graphene to one of the most coveted materials on the planet.
But its graphene’s unique electrical and thermal conductive properties that make it
so attractive to battery researchers.
To understand why that is, let’s break down the different parts of a battery so we can
better understand how different breakthroughs could help give us a better battery.
At it’s core a battery takes input energy and stores it, to get output energy at a later
time.
If it helps think about two water tanks, one on the floor, and one on your roof.
You could exert some energy and carry buckets of water from the floor tank and pour it on
your roof tank.
Then later when you needed, open a valve and let this water flow back down via gravity,
and power a water wheel.
This is gravitational potential energy, and we’ve basically built a gravity battery.
But a gravity battery has super low energy density, you’d need lake on a hill, to really
store any energy this way.
To power our phones and cars, we need something much more energy dense, like a chemical battery.
In a conventional lithium ion battery, we have a few parts.
The cathode The anode
A separator An electrolyte
Electrodes on both the anode and cathode to carry electrons
Traditional lithium ion batteries have graphite anodes, and various types of cathodes like
NMO (nickel manganese oxide) or NMC (nickel manganese cobalt).
In very broad strokes, cathodes are selected for their ability to attract an electron from
lithium, leaving lithium ion, a positive element missing 1 electron.
When a battery is charged, this lithium ion travels through the electrolye through the
separator and gets intercalated or wedged into the graphite lattice
in the anode.
The
first way we can improve on todays battery, is by replacing the graphite in the anode
with graphene.
Graphite’s hexagonal honeycomb structure means it takes 6 carbon atoms to hold on to
one lithium ion.
And this is what limits how much charge a battery can hold.
Graphene, though still a hexagonal honeycomb lattice, is only 1 atom thick, and able to
hold lithium ions on both faces, and even the edges.
As a result graphene has a theoretical capacity of 744 mAh/g compared to graphite at 372 mAh/g.
Here is a chart of the mass of various parts of a Lithium Manganese Oxide EV Battery.
33% of the weight is cathode, and 15% anode.
If we used the theoretical values for graphene, we could reduce its weight by 6% to just 9%,
we could use that mass for the cathode instead, increasing it to 39% of the total battery
weight, and increase energy density by 18%.
That means a 300 mile range Tesla Model 3, could now go 354 miles.
With no added weight.
But it get’s even more interesting, if we look back at that table, you’ll see there’s
11% copper and 19% aluminum in the battery mass.
These are the electrodes, or current collectors where the electrons travel through.
Aluminum is on the cathode side, even though its a worse electrical conductor than copper,
because copper reacts with lithium in adverse ways.
Copper is used as the current collector on the anode side, as shown on this amazing animation
by Jordan on his channel the Limiting Factor.
In fact after this video, go check out this video he made, trust me you’ll thank me
later.
So this then gets into the next benefit of graphene, its electrical conductivity.
The copper electrode is 200x more electrically conductive than the graphite anode.
But if we swapped the graphite anode for a graphene one, we might not need the copper
at all.
That’s because the entire graphene anode conducts electricity 333 times better than
graphite, or 68% better than even copper!
So if we coulde get away from needing copper at all, or even reduce the amount, that extra
mass we saved could again go into more cathode and anode material.
Future research could possibly even allow for a graphene current collector on the cathode
side, reducing the level of aluminum and increase energy density further.
Ok so that’s a look at how graphene can help with the battery anode, but its worth
pointing out, there’s a lot of research going into battery anodes that doesn’t require
any graphene.
The other new kid on the block is silicon, and it has the ability to store 10x more lithium
ions than graphite.
Tesla’s batteries today already have a small percent of silicon in its anode, and I had
the chance to chat with Fabrice Hudry of One D Battery sciences.
(INSERT INTERVIEW)
So while graphene isn’t the only game in town when it comes to a better anode, it does
have another very special property, and that is its thermal conductivity.
Graphene then is basically a world record setting material for both thermal and electrical
conductivity.
It’s this combination that allows for one of graphenes greatest benefits.
Super fast charging.
Imagine charging your ev to 80% in just 8 minutes, something that can take over 40 minutes
today.
That’s pretty much as fast as a gas fillup, and something the Chinese Company GAC plans
to promote in their upcoming models.
GAC First made the news by offering a 1000km range EV with their Aion LX plus, which uses
a silicon sponge anode(link).
But they have also made the news for some groundbreaking progress on a graphene anode
battery capable of charging at 6C.
1C means a battery can charge or discharge 0-100% in 1 hour.
6C then means it can do this in just 10 minutes.
The limiting factor when it comes to battery charging speeds is all the heat that it produces.
No battery is 100% efficient, so some of the energy used to charge ends up as heat, instead
of energy stored.
To understand how graphene can help batteries in terms of heat, let’s look at the thermal
conductivity of graphite, aluminum, copper and graphene.
Aluminum conducts heat 1.6x better than graphite, Copper 2.7x better than graphite, and its
this quality that makes copper used in electric wiring in everything from electronics, to
evs and homes.
But graphene, is absolutely off the charts, at 23x better than graphite.
If i were to hold a meter long plate of a poor insulator like ceramic on one side, and
take a blowtorch to the other, my hands would barely even get warm.
The heat just doesn’t transfer well through ceramic, in contrast, do the same thing to
a plate of copper, and before long, it’ll get too hot to touch.
But take a plate of graphene, and the heat will race to your hand.
This is an excellent property for a battery material, because with a well designed cooling
solution like most EVs have, and most the heat of the battery will be sucked out of
the battery walls via cooling ribbons.
Its this combination of excellent thermal and electrical conductor, that makes graphene
so lucrative for batteries.
Ok so we can increase energy density with graphene in the anode, and dramatically increase
charging speeds throughout the battery, but there’s one more benefit we need to talk
about.
Thanks primarily to Tesla, we’ve seen lithium ion battery prices plummet in the past decade.
From nearly $1,200 / kWh in 2010, to just $137 in 2020.
This is largely due to the production of more and more battery factories, and increases
in supply due to increases in EV demand, again primarily due to Tesla.
But here’s the thing, while manufactured lithium ion battery prices have been falling,
the same can’t be said for the price of raw lithium.(link)
The prices for raw lithium have been pretty steady in the same period, except for a small
price rise in 2018, until prices came back down in 2020.
But since, lithium prices are absolutely soaring.
Whether its massive demand for EV batteries, the pandemic or a host of other factors, this
will be the biggest challenge for lithium in the coming decade.
It’s not just the prices, lithium is also not especially abundant on earth.
Here is a chart of crustal abundance in PPM for some various elements.
Graphite 480
Copper 50
Graphene 480
Lithium 20
Aluminum 82000
Graphite comes in at 480PPM, Copper at just 50, but Lithium comes in at just 20 PPM.
Compared to the most abundant metal in the earth’s crust Aluminum which comes in at
82,000 PPM.
This abundance of aluminum would make it a killer choice for batteries, in fact we’ve
done a video on the aluminum air battery which we’ll link in the show notes.
But that is a primary cell, meaning it can’t be recharged.
Instead you’d bring your car with a depleted battery, have it swapped out, and that old
pack would have to be recycled.
Researchers at the University of Queensland in Australia have successfully developed a
graphene-based supercapacitor/ battery hybrid.
Remember, we talked all about supercapacitors in our previous video, which you should definitely
check out.
This battery uses aluminum, so technically its a graphene aluminum battery.
Director Professor Alan Rowan and his team of researchers have been working on devising
ways to make graphene into a more efficient electrode for powering batteries.
This hybrid battery ivolves embedding aluminum ions into a perforated graphene mesh.
This graphene-aluminum latter acts as the cathode while the anode is made of pure aluminium
foil.
The research caught the attention of the Australia-based Graphene Manufacturing Group or GMG, who are
in the process of applying this breakhtorugh research to battery cells which they plan
to introduce to the market within the next year or two.
Prototype batteries can reportedly charge between 60 and 70 times faster than lithium
ion batteries.
Even if this is only theoretical, it’s no stretch to imagine these batteries charing
to 80% in just a few minutes.
And, because graphene conducts heat far better than lithium, researchers suggest their batteries
could last 3x as long as standard lithium ion batteries!
Now, there is a catch with this technology.
Right now, these graphene-aluminum hybrid batteries have energy-densities between 150
and 160 watt hours/ kg.
Tesla's 4680-type battery cell has a density ranging between 272-296 Wh/kg —almost double
the amount of energy!
Even Tesla's current Model 3 cells have about 260 wH/kg, with an average range of about
330 miles.
Assuming graphene aluminum batteries of similar weight, that means they’d max out around
115 miles on a single charge.
So in that sense these batteries don’t quite stack up yet.
But, remember they can charge up to 70 times faster than lithium-ion batteries.
Which means in the real world, the experience may be closer to pulling in to a station for
a quick recharge before heading back on the road.
In fact, in may even be faster than filling up a car with gas.
This could make plug-in EVs more accessible, especially for people who don’t have access
to home chargers.
Plus how about busses or other commercial vehicles and cargo ships, where the added
weight wouldn’t really be a problem.
As of June 2022, the company has commissioned its graphene aluminium-ion batteries (“G+AI
Batteries”) in pouch cell format and that the first G+Al battery pouch cells have been
manufactured.
Currently, their tech is being utilized at a pilot plant.
While the batteries aren’t going to hit the market just yet, these are major steps,
meaning the technology is closer than ever!
But its not just the batteries themselves that are a big deal.
As I said before, one of the biggest things keeping graphene from hitting the market is
cost.
One way GMG has worked around that is by developing methods for mass producing their own graphene!
While the method is propriety, and therefore kept pretty tightly underwraps, their means
of developing graphene brings the cost down significantly.
Not only that, but the process could potentially be a win for the environment.
Again, the exact process is abit of a mystery, but according to the company it involves a
process that converts methane into hydrogen and graphene, essentially a form of carbon
capture.
So then there you have it, graphene can revolutionize the battery in quite a few ways, and is being
pursued by quite a few different companies.
Ditching rare metals like lithium and cobalt in favor of aluminum would be the game changer
of game chargers, and would all but render fossil fuels obsolete.
But the the great big elephant in the room is how we’re going to produce graphene at
a commercial scale.
Is researching being done today going to lead to a future where graphene is as common as
graphite?
Or will graphene costs and supplies always keep it out of reach.
Sadly this, as it ever has been, is the great unknown.
But before you leave a comment saying graphene will never be a thing, just remember that’s
what everyone said about everything until it wasn’t.
There was a time when many wrote of lithium ion batteries as a fools errand, and yet here
we are.
That’s the beauty of science, and why i get excited thinking about all the brilliant
minds hard at work on the great challenges of tomorrow.
Hopefully this look should give you an idea for why I’m so excited about graphene, and
obviously it isn’t just me.
Let’s hope for some good news on graphene manufacturing breakthroughs like the ones
GMG is working on in the very near future.
A world full of dirt cheap batteries just cant come soon enough.
But what do you think?
What aspect of graphene has you most excited?
Sound off in the comments below.