While there will no doubt be exciting showcase technology and plenty of “one more thing” elements, Elon Musk has probably already revealed the main battery tech that will enable Tesla to massively scale it’s mission to accelerate the transition to sustainable energy (and transport).

Not everyone knows that LFP battery packs are at least 20% cheaper per kWh than nickel-based battery packs, and that LFP cathodes have no mineral supply constraints or price spikes (unlike nickel cells).

“The real limitation on Tesla growth is cell production at an affordable price, that’s the real limit, so that’s why we’re going to talk a lot more about this on battery day, because this is the fundamental scaling constraint.”.

Nickel based cells have higher energy density so longer range obviously those are needed for something like the Semi where every unit of mass that you add in battery pack you have to subtract in cargo.

“However, what we’re seeing with our passenger vehicles is that total vehicle efficiency has gotten good enough that we actually are comfortable having an LFP pack in Model 3 in China, and that will be in volume production later this year.

I have written about the economics and properties of LFP cells and nickel-cobalt cells for electric vehicles several times (check here, here, and here), so maybe I have a different perspective from most Tesla watchers.

The higher energy density of nickel-cobalt cells (compared to LFP) is well suited to long-range, weight-sensitive electric vehicles like the Tesla Semi.

However (in contrast) for Tesla passenger vehicles (especially the entry level vehicles not needing 400+ miles of range, or crazy power-to-weight performance ratios), Tesla’s many years of accumulating powertrain and other efficiencies mean that even the more modest energy density of LFP is now sufficient to give almost 300 miles of range.

Conclusion: we are now at a point where the lowest-cost EV battery technology, LFP, despite its lower energy density, has enough energy to power Tesla’s highest-volume entry level vehicles with a range of close to 300 miles.

The 2012 Tesla Model S was already capable of 265 miles of rated range and 35 minutes of charging for decent onward journey progress.

The 2017 Tesla Model 3 was already capable of around 300 miles of range and 20 minutes of charging for decent onward progress.

As time goes on, the efficiency of EVs will keep improving ever further, requiring less battery energy to deliver competent and convenient range.

Precisely these dynamics led to the arrangement between Tesla and battery maker CATL to supply LFP cells for its Shanghai Gigafactory Model 3, news of which broke in February 2020.

Given the discussion above, obviously, this higher energy density is no longer strictly required for capable-enough-for-mass-market electric vehicles, and struggles to compete with LFP on cost, for this class of vehicles.

However, the energy density advantage of nickel-cobalt will remain very relevant for halo battery electric products like very long range EVs (over 300 miles or even 400 miles), and high performance EVs where relative light weighting is still very desirable.

But the point of Roadrunner is to implement new approaches to efficient cell manufacturing, like Tesla’s energy efficient dry electrode production process, which doesn’t need solvent drying ovens.

Since this is the first record we have of Tesla producing their own in-house cells at a commercial volume, and R&D is part of the intention, we have to imagine that they will incorporate their Maxwell Technology subsidiary’s dry battery electrode production process.

Along with all of these, there are very likely a few other battery technology innovations, and manufacturing innovations, Tesla will be employing in this production line, that we don’t yet know about.

It is clear that Tesla intends this Roadrunner battery project to produce cutting edge cells in terms of energy density, power density (C-rates of both charge and discharge), thermal performance, and cycle life also.

Presumably they intend to prove out new methods in manufacturing efficiency (speed, energy, capital cost, yield) and thus also improved $/kWh cost of cells (compared to existing commercial nickel cobalt cells).

Since the Roadrunner cells will most likely quickly become the highest energy density available to Tesla at commercial volume, the company will almost certainly be deploying them in cutting edge applications.

Logically, these applications will be the forthcoming Semi Truck and the Roadster, and the upcoming Plaid Tesla Model S and Model X.

In order to head off another upcoming extreme long range challenger from Lucid, Tesla may also announce an ultra long range variant of the Model S with a ~130 kWh Roadrunner battery which should achieve a Lucid-beating 525+ mile EPA rating (or more).

Since initially the Roadrunner cells will be expensive to produce and available in only moderate volumes, these nearterm Plaid and ultra long range vehicles will command high prices commensurate with their exclusivity and initially limited production volumes.

Before long we can expect further ramp up of production of Roadrunner cells, likely in some portion of Tesla’s gigafactories; very likely in Texas where the Tesla Semi and Cybertruck will be produced.

Tesla may also work with Panasonic at Gigafactory Nevada to produce Roadrunner cells.

More on how Tesla may scale Roadrunner cells below.

We have seen that even modest energy density LFP cells will power very compelling yet affordable vehicles, which will become Tesla’s best sellers by volume.

Tesla may also be able to bring some of their battery technologies like dry electrode, tabless electrode, electrolyte doping to bear on LFP cells, perhaps in partnership with CATL, perhaps ultimately with their own LFP production.

These are the Panasonic NCA cells that supply “Long Range” and “Performance” vehicles, and LG’s NCM cells that power Tesla’s Long Range Model 3s and soon Model Ys in China.

Add to that available palette the in-house Roadrunner cells, which ensures that Tesla is not dependent on anyone else’s technology to maintain its reputation for being at the cutting edge of halo electric vehicles and frontier applications (like long range Semi Trucks), and Tesla should be in a strong position.

Related to the non-dependence point, this flexible strategy, drawing on diverse types of cells, allows Tesla to hedge against the vagaries of the mineral supplies and cost fluctuations, especially those for nickel and cobalt.

Having access to a stable low price technology like LFP means that Tesla’s core business of making and selling ever higher volumes of battery electric vehicles and battery energy products is shielded from these fluctuations and potential bottlenecks.

As Drew Baglino said in the 2019 annual meeting, in regard to Tesla needing a large scale solution to battery cell production, “We are not sitting idly by, we’re taking all the moves to be masters of our own destiny here, technologically and otherwise.”.

Even below 70%, the battery and its cells will still be valuable for less energy dense uses, such as in stationary storage applications.

As we covered above, LFP isn’t a good fit for weight sensitive applications like the Tesla Semi Truck, so despite some varieties of LFP working beyond 2,500 cycles already, the Semi will use nickel based versions of a “million mile battery”.

This will be okay in the short term if only the Plaid S and X, ultra long range S and X, and initial units of the Tesla Semi need to be supplied.

But each Semi will probably use at least 800-1000 kWh of cells, so when these vehicles scale beyond a few hundred units per year the Roadrunner battery production will have to scale up.

However, if Tesla’s Roadrunner cells work out as cost efficient and high performance as they are planned to, it would only make sense for Tesla to ramp up the manufacturing capacity, since they will likely be the most cost competitive nickel cells available.

I will also concede that if the tabless electrode design of the Roadrunner cells works exceptionally well, extreme battery heating may be significantly mitigated anyway?

We already know that the Model Y’s heat pump and octovalve will eventually make their way to all other Tesla vehicles, since Elon referred to this when discussing “our passenger vehicles” and efficiency, above.

The Semi Truck will likely not yet be announced as production ready, but we may see a formal update announcement on its gaining range to 600 or more miles, thanks to the Roadrunner cells?

Tesla’s Roadrunner nickel batteries will incorporate all of Tesla’s battery technologies and break new ground in overall performance terms

Tesla will keep Roadrunner in-house or in tight manufacturing partnerships (Panasonic and/or LG), and gradually expand Roadrunner production volume in Austin, Berlin, and possibly the other Gigafactories

Tags: battery minerals, CATL, Elon Musk, EV batteries, LFP, LG Chem, lithium iron phosphate, lithium iron phosphate battery, mineral extraction, mining, NCA, NCM, Nickel Cobalt Aluminium batteries, Nickel Cobalt Manganese batteries, panasonic, Tesla, Tesla batteries, Tesla Model 3, Tesla Model S, Tesla Model S Plaid, Tesla Model X, Tesla Model X Plaid, Tesla Model Y, Tesla Semi, Tesla Semi Truck