Welcome to another Two Bit da Vinci Video, where today we are going to talk about “The
Truth about Tesla’s Batteries.”
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subscribe and take part of our future polls to see what topics we cover next.
If you’re thinking about a Tesla, you’ve undoubtedly heard about how cheap they are
to fill up, how little maintenance they require, and with recent Model 3 Production ramp ups,
we’re on the verge of absolute Tesla ubiquity.
But one of the questions that we believe keep potential buyers up at night, surrounds their
battery packs.
So we’ve compiled a list of all the questions we’ve received, and we’re going to break
it down, step by step in this two part video series.
To understand the battery technology, its important to think about it in these categories.
First we’ll look at the raw materials required to create lithium ion batteries.
Second we’ll look at the battery cell manufacturing.
In part 2, we’ll look at the complete battery pack manufacturing, the final Car manufacturing,
and end of life recycling of lithium ion batteries.
The first step in this journey has to begin with the acquisition of the raw materials
that make EV’s possible.
We’re often told that mining operations for lithium and other battery materials is
worse for the environment then just making petrol cars.
So is that true, are we destroying the world by making battery packs for EVs?
Let’s break this down element by element.
Different car makers use different cathode chemistries for lithium ion batteries, Tesla
uses NCA chemistry, or Nickel, Cobalt, and Aluminium (LiNiCoAlO2).
They use this particular chemistry because it offers great energy density, long cycle
life, and great charge performance.
This makes Tesla’s batteries the absolute top of the line in the EV world.
They weigh less, last longer, and power the performance of things like Ludicrous mode.
Most other EV manufacturers have opted to use NMC or Nickel Manganese Cobalt, which
has slightly lower energy density, but is regarded as a safer battery.
More on all of this later.
Tesla’s Batteries have gone through 3 stages: Stage 1 was from 2009-2012 found in the Roadster
and Model S. Stage 2 was from 2016-2018 and powered the Model S Gen II, and the Model
X.
Stage 3 starts with the Model 3 in 2018.
So what’s changed, and how are they improving?
Stage 1 batteries were constructed with 18650 cells, which are 18 mm wide, and 65 mm tall.
They had a NCA formulation that required 11kgs of Cobalt in the cathode, per car.
They had a pure graphite anode, with no Silicon.
Stage 2 batteries used the same 18650 cells, but reduced the amount of Cobalt required
in the cathode from 11 to just 7kg/car.
They also introduced a small amount of silicon into their anode.
So let’s talk about anodes, where common materials include graphite and silicon.
Both Graphite, a very common stable form of Carbon, and Silicon live on the same column
of the Periodic table, giving them 4 valence electrons.
This ability to form 4 covalent bonds not only makes Carbon the building block of all
life on Earth, but also a great anode material.
Silicon is very similar, but allows 10x the energy capacity of Graphite.
It’s clear that Silicon anodes are the future, but the problem with Silicon is that, while
Graphite expands about 7-10% in volume from empty to fully charged, Silicon expands between
300-400%!
This is a big problem, because while pure Silicon anodes, could use less material, allowing
for larger cathodes, and thus greater energy density, the repeated expansion and collapse
during charge/discharge cycles severely reduces its operating life.
So in Tesla’s Stage 2 batteries, they use a hybrid Graphite/Silicon anode, with between
5-15% Silicon.
Stage 3 batteries are new for Tesla, and first shipped with the Model 3.
Stage 3 batteries have further reduced the amount of cobalt to just around 4.5kg per
vehicle.
They also have a hybrid silicon/graphite anode, and while proprietary and unreported, probably
higher silicon content than their stage 2 batteries.
So why is lithium so popular for cathodes?
Let’s look at the left-most column of the Periodic Table.
These are the alkali metals, and they all have one valence electron.
So metals here are likely to give up one electron, which is very important in the production
of electricity, and Lithium is the lightest metal.
It turns out, that Lithium is the 25th most abundant element on earth.
However, it only makes up .0007% of the Earth’s crust.
Most lithium extraction actually happens in liquid brine pools.
Water is evaporated off by the sun and the lithium compounds can be extracted.
A majority of current current lithium deposits are in the Lithium Triangle of Bolivia, Chile,
and Argentina.
Australia and China are also big markets, and their role will only increase in the future.
There’s also lithium in the oceans and estimates place it around 230 billion tonnes, but is
in very low concentrations.
Though there are no companies extracting Lithium from the World’s oceans today, when demand
rises or supplies dwindle to the point where it’s profitable, you can be sure that they
will.
The price for Lithium is right around $7.50USD per lb as of 2018, and looking at the past
prices, you can see Lithium has been surging, and prices in the future will hinge upon supply,
as demand is just getting started.
Next up is nickel which has an abundance of 0.009% in the Earth’s Crust.
Nickel is widely viewed as the most important element for EV batteries, and looking at this
graph, you can see it’s the largest constituent in Tesla Batteries by mass.
It plays a pretty big role in battery packs for other manufacturers as well, and will
be a key element as worldwide EVs shipments continue to rise.
Nickel prices are around $4.00 / lb in 2018 and Canada is Tesla best bet for a pure North
American supply chain.
Next we have Cobalt which comprises 0.003% of the Earth’s crust.
Now this is where things get interesting, because Cobalt is the most critical element
in their battery supply chain.
Cobalt is the most expensive material here, costing just shy of $40/lb in 2018.
This is due to is scarcity, but also due to the fact that over 60% of worldwide production
comes from the Democratic Republic of Congo.
Political turmoil, child labor concerns, and violence in this region, make Cobalt the most
critical element in the supply chain, and it’s no surprise that Tesla is reducing
its reliance on Cobalt with each generation of battery.
Manganese comprises 0.11% (774) of the Earth’s crust, making it the 12th most abundant element.
You’ll notice there is no manganese in Tesla’s batteries, while it is used on most other
EVs.
This is an interesting move for tesla, considering Manganese is so cheap at only $0.93/lb in
2018, but when you factor a larger requirement for Cobalt, in NMC batteries, its less surprising.
There’s also a small amount of Aluminium in the NCA battery, but luckily it is the
7th most abundant element on Earth by mass, and has a very mature supply chain, due to
its use in everything from cans, cars and aircrafts.
This makes Aluminium very affordable at only $0.86/lb.
So this is not a concern at all for Tesla.
Now all those elements are used in the cathode, and the story in the anode is simpler, where
there’s graphite, which costs roughly $0.60 / lbs and an average Tesla battery pack contains
about 54 kg of graphite.
While only 25% of graphite was used for batteries in 2012, that number is use rise substantially.
There isn’t too much concern here, especially considering graphite can be created synthetically
in the lab, and as demand soars, synthetic graphite labs are sure to pop up.
We wanted to talk about the raw materials, because unlike other companies that are planning
to sell tens of thousands of EVs each year, Tesla is planning to sell half a million and
then a million EVs each year.
It's absolutely crucial to understand supply chain fragility when considering that lithium
ion battery production is set to soar.
The good news is all these materials have been mined for decades, and most data suggests
there won’t be any issues with supply limitations for Tesla’s goals of a million cars a year.
But as more manufacturers start believing in the same vision, there’s sure to be a
strain on some of the critical elements.
So be sure to stay up to date with the raw material supply chain news, because it will
be absolutely critical in the next 10 years.
We aren’t going to cover the environmental impact of mining battery materials vs. petrol
cars in this video, but make sure to subscribe for a future video where we’ll do just that.
Now that we’ve gotten that out of the way, let's talk about the battery cell manufacturing.
As you’ve probably heard, Tesla opened Gigafactory 1 in Sparks Nevada, and though it will only
be fully completed by 2020, its pumping out batteries, and will only increase its production
rate as it nears completion.
Tesla has switched from 18650 cells to 21700 cells because it’s an optimized size to
maximize energy, with minimal increases in weight, and excellent cost.
Voltage is largely unchanged, since its a function of battery chemistry.
So the big question here is, why does Tesla use these little battery cells, when they
know they’ll need thousands of them?
Why not not make custom big batteries, like the ones found on a BMW i3?
The i3 uses prismatic batteries, with big custom packs.
The Chevy bolt and Leaf use rectangular pouch batteries, which you might think makes more
sense since there’s less wasted space.
But to understand Tesla’s choice of cylindrical small cells, we have to consider commonality
vs. customization, and design flexibility.
The i3’s prismatic battery and the Bolts pouch battery have to be specifically made
for those cars.
They are built to specification, much like your smartphone.
Figure out how much space you have left for a battery, then get one custom made.
In contrast, the Tesla model 3 uses a new 2170 cell which will be the battery that powers
all future tesla models and even their home energy storage solutions.
Need more volts?
Put cells together in series, need higher capacity?
Put those cells in parallel with other cells.
In this way, Tesla can absolutely mass produce these cells, and configure them based on car.
This flexibility is why Tesla can offer a wide variety of range options.
By adding more cell blocks in parallel they can increase range without changing the core
voltage of the system.
Tesla has a goal of producing batteries at less than $100/kWh.
This is very ambitious, and this small cell philosophy, with the newly optimized 2170
cell is there recipe for success.
The Gigafactory is Tesla’s greatest asset, because by investing so heavily into a vertical
integration structure, they can control costs and production levels.
In contrast General Motors, completely outsources the battery development to LG Chem, who provide
complete units ready to drop into their EVs.
But if suddenly Honda and Toyota come with contracts to LG Chem, how would that impact
GM?
Vertical integration for battery manufacture is super costly, but does give Tesla a marked
advantage over their competition.
In fact, it might be their single biggest advantage.
One question we often get is who’s actually making the battery, Panasonic or Tesla?
The answer really is Panasonic.
The gigafactory is Tesla’s vision of their own production facility pumping out their
particular batteries, and they’re able to house Panasonic personnel in a symbiotic relationship.
It takes decades to master the chemistry of Batteries, and that’s where Panasonic comes
in.
The partnership is strong, and benefitting both companies.
We hope you enjoyed part one of this two part series on the Truth Behind Tesla Model 3 Batteries.
We wanted to break this up, because the story of the raw materials, is quite literally the
most important aspect of the future EV story.
Without stable and reliable supply chains, the Gigafactory would languish, and Tesla
Model 3 Production would grind to a halt.
We know we haven’t answered the biggest question of how long Model 3 batteries will
last, that comes next in part two of this series.
We really hope you’ll subscribe and join the community, and vote for future videos,
We’re two bit da vinci, thanks for watching.