AUSTIN, Texas – Elon Musk says prototypes are straightforward, manufacturing is hell. And in relation 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 fee of 1 / 4 of one million automobiles sooner or later throughout 2025.
However Tesla continues to be a good distance off that type of manufacturing tempo, and one of many important bottlenecks is the velocity it may make the 4680 batteries used within the Cybertruck with its new dry-coating know-how, 9 individuals aware of the matter mentioned.
Tesla’s Giga Texas manufacturing unit is at present churning out 4680 battery cells at fee solely ample to energy about 24,000 Cybertrucks a 12 months, or a few tenth of the required output, in line with Reuters calculations based mostly on a mix of public knowledge and unpublished figures offered by sources.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 – moderately than utilizing the slower, extra pricey 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 individuals, 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 individuals mentioned dry-coating the anode within the 4680 cells was not problematic however Tesla was combating the identical method for the cathode – the most costly element in a battery.
Dry-coating anodes and cathodes is confirmed within the laboratory, in addition to for smaller power storage gadgets comparable to tremendous capacitors, and even some small batteries, in line with Yuan Gao, a battery know-how marketing consultant.
“However nobody has achieved it to date for big EV batteries at a mass scale and at a excessive sufficient velocity. Tesla is the primary one to attempt to commercialize this,” mentioned Gao, who has labored within the trade for 3 a long time.
“The problem is that not solely does Tesla need to scale it up and velocity up the method, it additionally should develop its personal gear and instruments. It is formidable to say the least,” he mentioned.
Tesla didn’t reply to detailed questions from Reuters for this story.
Cracking the code
In response to three of the sources, the 4680 batteries in Cybertrucks embrace an estimated 1,360 particular person cells.
Which means Tesla would want to make 340 million cells a 12 months, or nearly one million a day, to provide 250,000 of the electrical pickups, that are getting into a scorching market with rivals comparable to Ford’s F-150 Lightning, Rivian’s R1T and an electrical Hummer from Basic Motors.
For the time being, Tesla’s Austin manufacturing unit takes about 16 weeks to make 10 million 4680 cells, in line with Reuters calculations based mostly on figures from Tesla, verified by the three sources.
That interprets to 32.5 million cells a 12 months, or sufficient for just below 24,000 pickups – and that is just for the Cybertruck.
Tesla additionally desires to make use of 4680 batteries to energy different automobiles, most notably the $25,000 small automotive 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’s primarily for pilot manufacturing. Panasonic, one in every of Tesla’s long-standing battery suppliers, is planning to construct at the least two vegetation in the USA however has solely simply damaged floor on the primary.
Two of the 9 individuals aware of 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 sturdy know-how to supply batteries with out flaws first time spherical. It is a time-consuming course of however, “when you crack the code and set up stability, it’s like exponential”, one in every of them mentioned.
“Velocity would decide up. There may be already lots of traction in dry coating,” the individual mentioned.
Tesla’s battery tsar Drew Baglino mentioned in October that the corporate was now producing 4680 cells on two manufacturing traces in Austin and plans to put in a complete of eight traces there in two phases, with the final 4 attributable to be operating in late 2024.
Nonetheless, one of many two individuals mentioned replicating established know-how from one manufacturing line to the subsequent isn’t any cakewalk.
The supply mentioned solely about 5% of cells made on worthwhile manufacturing traces are ditched however scrap charges might 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 technique 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.
The sources mentioned Tesla was struggling to combine the cathode supplies, which embrace 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 individuals 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 often called Teflon.
“In case you soften the glue, fairly quickly all the things will grow to be one large 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 large journal and newspaper printing machines with massive rollers, the sources mentioned.
To speed up cell manufacturing, Tesla is attempting to coat a number of strips of magnetic foil with lively battery supplies on the similar time, and at excessive speeds.
That calls for big, broad rollers, in addition to making use of large pressure to press the supplies onto the foil. However as a result of the rollers are massive and broad, making use of strain evenly is proving to be a problem, the sources mentioned.
And when strain is just not utilized evenly, Tesla will get electrodes with uneven surfaces and thickness, which are not any use for its battery cells and must be scrapped, the sources mentioned.
Maybe extra problematic, Tesla’s Baglino advised a hearth chat at a battery convention in March that Tesla was nonetheless constructing a totally new high quality verification system so they might 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 improvement, 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 must be junked, the supply mentioned.
(Reporting by Norihiko Shirouzu in Austin and Paul Lienert in Detroit; Modifying by David Clarke)