By Norihiko Shirouzu and Paul Lienert
AUSTIN, Texas (Reuters) – Elon Musk says prototypes are simple, 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 stated in October that it could most likely hit an annual manufacturing charge of 1 / 4 of one million autos in some unspecified time in the future throughout 2025.
However Tesla remains to be a great distance off that sort of manufacturing tempo, and one of many foremost bottlenecks is the pace it may possibly make the 4680 batteries used within the Cybertruck with its new dry-coating expertise, 9 folks conversant in the matter stated.
Tesla’s Giga Texas manufacturing facility is at the moment churning out 4680 battery cells at charge solely adequate to energy about 24,000 Cybertrucks a yr, or a few tenth of the required output, in accordance with Reuters calculations primarily based on a mix of public knowledge and unpublished figures offered by sources.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 could 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, stated 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 stated dry-coating the anode within the 4680 cells was not problematic however Tesla was scuffling with the identical method 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 vitality storage units akin to tremendous capacitors, and even some small batteries, in accordance with Yuan Gao, a battery expertise guide.
“However nobody has finished it to date for giant EV batteries at a mass scale and at a excessive sufficient pace. Tesla is the primary one to attempt to commercialize this,” stated Gao, who has labored within the business for 3 a long time.
“The problem is that not solely does Tesla need to scale it up and pace up the method, it additionally should develop its personal tools and instruments. It is formidable to say the least,” he stated.
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.
Meaning Tesla would wish to make 340 million cells a yr, or nearly one million a day, to provide 250,000 of the electrical pickups, that are coming into a scorching market with rivals akin to Ford’s F-150 Lightning, Rivian’s R1T and an electrical Hummer from Normal Motors.
For the time being, Tesla’s Austin manufacturing facility takes about 16 weeks to make 10 million 4680 cells, in accordance with Reuters calculations primarily based on figures from Tesla, verified by the three sources.
That interprets to 32.5 million cells a yr, 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 autos, 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 may be primarily for pilot manufacturing. Panasonic, one among Tesla’s long-standing battery suppliers, is planning to construct not less than two crops in the USA however has solely simply damaged floor on the primary.
Two of the 9 folks conversant in the matter consider Tesla’s progress with scaling up 4680 manufacturing will probably achieve steam, particularly as soon as it achieves stability with the manufacturing know-how on one manufacturing line.
They stated 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, “when you crack the code and set up stability, it’s like exponential”, one among them stated.
“Velocity would choose up. There may be already a whole lot of traction in dry coating,” the particular person stated.
Tesla’s battery tsar Drew Baglino stated 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 folks stated replicating established know-how from one manufacturing line to the following is not any cakewalk.
The supply stated 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 stated Tesla’s dry-coating technique for cathodes was not proving to be any sooner 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 stated 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 stated the method labored for small quantities however when Tesla tried to scale it up, a whole lot of warmth was generated and this melted the binder, which one of many sources believed was polytetrafluoroethylene, extra generally often called Teflon.
“Should you soften the glue, fairly quickly every little thing will turn into one large chunk of gooey mess,” one other of the sources stated.
Equally problematic for Tesla are the machines used to coat the metallic foil to supply battery electrodes – tools which is akin to large journal and newspaper printing machines with giant rollers, the sources stated.
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 giant, vast rollers, in addition to making use of great pressure to press the supplies onto the foil. However as a result of the rollers are giant and vast, making use of strain evenly is proving to be a problem, the sources stated.
And when strain will not be utilized evenly, Tesla will get electrodes with uneven surfaces and thickness, which are not any use for its battery cells and have to be scrapped, the sources stated.
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, stated 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 have to be junked, the supply stated.
(Reporting by Norihiko Shirouzu in Austin and Paul Lienert in Detroit; Enhancing by David Clarke)
