Interesting report out of China saying that Tesla had to buy cathode coils from tier 2 suppliers in China to bridge a shortfall of 4680 production. CATL and BYD declined to supply them since they only want to supply complete cells. Tesla hasn’t been able to make enough cathodes for their 4680 production goals, apparently due to their inability to yield cathode DBE. This occurred in 2023 and may persist well into this year.
Tesla began purchasing cathode coils from two second-tier Chinese battery makers in the second half of 2023 and shipping them to its Texas factory in the US to produce 4680 batteries, according to local media.
cnevpost.com
My long standing opinion on ramp progress for 4680s remains unchanged.
I will not be concerned about progress until 6 months after the Cathode plant is complete and operational.
Reasons why Tesla might be building the Cathode plant (in order of importance) are:-
- Quality.
- Quantity.
- Price.
My hunch is quality is top of the list because DBE cathodes strike me as the kind of recipe where the quality of the ingredients might have a big impact on the outcome.
If quality is an issue it might be why Tesla had no choice, they had to build the cathode plant.
For example, quality might be :- "single crystal cathode with a particular uniform crystal size with fine tolerances".
I would not be surprised if something like that was true, and there was a trade off, where smaller crystal sizes worked better for DBE, at the cost of some energy density.
Larger crystal cathodes might dent or damage roller equipment, non-uniform sizes might affect yield, multi-crystal cathodes might crack during rolling, impacting on yield and possibly damaging equipment.
The reason Tesla might not be using the ideal cathode raw materials at present is, it may be impossible to buy sufficient volumes at the right grade for a good price.
I might be wrong, but if it isn't a problem related to ingredient quality, it is ultimately some problem that can be solved. Or at worst Tesla can construct a wet cathode plant somewhere.
IMO the cathode plant is more likely to be making high quality cathode ingredients, rather than a wet cathode..
Why wasn't the Cathode plant built earlier? it could be that getting the design and equipment right was important, and there could have been long lead times on some of the necessary equipment.
Why hasn't tesla told us why they are building the Cathode plant? Maybe they want competitors to assume it is all about quantity and price, when quality is the most important criteria.