AUSTIN, Texas – Elon Musk says prototypes are straightforward, manufacturing is hell. And with regards to the long-awaited Cybertruck, Tesla’s hell is its pioneering 4680 battery.
Tesla delivered the primary of its futuristic stainless steel-plated electrical pickups final month and CEO Musk mentioned in October that it might most likely hit an annual manufacturing price of 1 / 4 of one million autos in some unspecified time in the future throughout 2025.
However Tesla continues to be a great distance off that form of manufacturing tempo, and one of many predominant bottlenecks is the velocity it may well make the 4680 batteries used within the Cybertruck with its new dry-coating know-how, 9 folks accustomed to the matter mentioned.
Tesla’s Giga Texas manufacturing facility is presently churning out 4680 battery cells at price solely adequate to energy about 24,000 Cybertrucks a yr, or a few tenth of the required output, in keeping with Reuters calculations based mostly on a mix of public knowledge and unpublished figures offered by sources.
Having the ability to ramp up battery output massively by dry-coating electrodes – somewhat than utilizing the slower, extra expensive wet-coating – was a key issue behind Tesla’s forecasts in 2020 that it might greater than halve battery prices, reduce funding considerably, and create smaller, greener factories.
The 9 folks, who spoke to Reuters on situation of anonymity due to the sensitivity of the matter, mentioned Tesla had but to crack dry-coating on the industrial scale wanted to make 4680 batteries quick sufficient to hit its manufacturing targets.
The folks mentioned dry-coating the anode within the 4680 cells was not problematic however Tesla was scuffling with the identical approach for the cathode – the most costly part in a battery.
Dry-coating anodes and cathodes is confirmed within the laboratory, in addition to for smaller power storage units corresponding to tremendous capacitors, and even some small batteries, in keeping with Yuan Gao, a battery know-how marketing consultant.
“But no one has done it so far for large EV batteries at a mass scale and at a high enough speed. Tesla is the first one to try to commercialize this,” mentioned Gao, who has labored within the trade for 3 a long time.
“The challenge is that not only does Tesla have to scale it up and speed up the process, it also must develop its own equipment and tools. It’s daunting to say the least,” he mentioned.
Tesla didn’t reply to detailed questions from Reuters for this story.
Cracking the code
In keeping with three of the sources, the 4680 batteries in Cybertrucks embody an estimated 1,360 particular person cells.
Which means Tesla would want to make 340 million cells a yr, or virtually one million a day, to provide 250,000 of the electrical pickups, that are getting into a sizzling market with rivals corresponding to Ford’s F-150 Lightning, Rivian’s R1T and an electrical Hummer from Common Motors.
For the time being, Tesla’s Austin manufacturing facility takes about 16 weeks to make 10 million 4680 cells, in keeping with Reuters calculations based mostly on figures from Tesla, verified by the three sources.
That interprets to 32.5 million cells a yr, or sufficient for slightly below 24,000 pickups – and that is just for the Cybertruck.
Tesla additionally desires to make use of 4680 batteries to energy different autos, most notably the $25,000 small automobile the corporate is scrambling to launch by the mid-2020s.
Tesla has some restricted manufacturing capability for 4680 cells in Fremont, California however its plant there may be primarily for pilot manufacturing. Panasonic, considered one of Tesla’s long-standing battery suppliers, is planning to construct at the very least two vegetation in america however has solely simply damaged floor on the primary.
Two of the 9 folks accustomed to the matter consider Tesla’s progress with scaling up 4680 manufacturing will possible achieve steam, particularly as soon as it achieves stability with the manufacturing know-how on one manufacturing line.
They mentioned Tesla had been specializing in establishing strong know-how to supply batteries with out flaws first time spherical. It is a time-consuming course of however, “once you crack the code and establish stability, it is like exponential”, considered one of them mentioned.
“Speed would pick up. There is already a lot of traction in dry coating,” the particular person mentioned.
Tesla’s battery tsar Drew Baglino mentioned in October that the corporate was now producing 4680 cells on two manufacturing strains in Austin and plans to put in a complete of eight strains there in two phases, with the final 4 as a consequence of be working in late 2024.
Nonetheless, one of many two folks mentioned replicating established know-how from one manufacturing line to the following is not any cakewalk.
The supply mentioned solely about 5% of cells made on worthwhile manufacturing strains are ditched however scrap charges may shoot as much as 30%-50% and hover there for a number of months as every new line will get going.
One of many sources mentioned Tesla’s dry-coating methodology for cathodes was not proving to be any quicker than the previous moist course of, although scrap charges had dropped to as little as 10% to twenty%.
Baglino didn’t reply to requests for remark for this story.
‘Gooey Mess’
The sources mentioned Tesla was struggling to combine the cathode supplies, which embody lithium, manganese and nickel, with a binder and stick them to a metallic foil to supply a cathode – with out utilizing moisture.
Two of the folks mentioned the method labored for small quantities however when Tesla tried to scale it up, lots of warmth was generated and this melted the binder, which one of many sources believed was polytetrafluoroethylene, extra generally generally known as Teflon.
“If you melt the glue, pretty soon everything will become one big chunk of gooey mess,” one other of the sources mentioned.
Equally problematic for Tesla are the machines used to coat the metallic foil to supply battery electrodes – gear which is akin to very large journal and newspaper printing machines with giant rollers, the sources mentioned.
To speed up cell manufacturing, Tesla is making an attempt to coat a number of strips of magnetic foil with energetic battery supplies on the identical time, and at excessive speeds.
That calls for giant, large rollers, in addition to making use of great drive to press the supplies onto the foil. However as a result of the rollers are giant and large, making use of strain evenly is proving to be a problem, the sources mentioned.
And when strain just isn’t utilized evenly, Tesla will get electrodes with uneven surfaces and thickness, which are not any use for its battery cells and should be scrapped, the sources mentioned.
Maybe extra problematic, Tesla’s Baglino instructed a hearth chat at a battery convention in March that Tesla was nonetheless constructing a very new high quality verification system so they may weed out cells with flaws in coating.
One of many sources with data of the matter, mentioned particularly it was about constructing knowledge infrastructure round Tesla’s battery growth, manufacturing and in-field use as a result of in some instances the issues had been hidden within the coating and didn’t present up for just a few months down the street.
In different phrases, Tesla does not fairly know but which dry cells are good, and which of them should be junked, the supply mentioned.
(Reporting by Norihiko Shirouzu in Austin and Paul Lienert in Detroit; Enhancing by David Clarke)