Written byMa Xiaolei.
EditWu Jing.
DesignDivision Chao.
Reuters, by Norihiko Shirouzu, Paul Lienert
Musk has personally admitted that the goal of "reaching 250,000 cybertrucks per year by 2025" is unlikely to be achieved, and Tesla is once again experiencing capacity bottlenecks. This time the Cybertruck's "production hell" is brought by the battery.
In 2019, Musk bought enough of a technology company called Maxwell Technologies, mainly because of its dry electrode process. And it is this new dry coating technology that makes the production of 4680 batteries challenging.
Tesla is currently manufacturing 4680 dry-coat electrode batteries at its Giga factory in Austin, Texas, where it will manufacture the Model Y and Cybertruck. Reuters said it interviewed nine people with knowledge of the inside of the Gigafactory in Austin. According to these sources, Tesla has not cracked the large-scale dry-coat process and is unable to produce 4680 cells fast enough.
To meet the demand for an annual production of 250,000 Cybertrucks, Tesla needs to achieve an annual production capacity of 3The goal of 400 million cells. In other words, the daily production should reach nearly 1 million.
In the past 4 months, the Austin factory has only produced 10 million 4680 battery cells, which can only **120,000 cybertrucks. Based on the calculation that the Cybertruck is equipped with a total of 1,360 cells, the annual output of 4,680 cells at the Austin plant is 32.5 million, which is only 24,000 Cybertrucks, which is only 10% of the target output.
According to the nine sources, the anode dry coating of the 4680 battery is currently fine, but the production of the cathode dry coating is experiencing difficulties - this is also the most expensive component of the battery. Expected to launch in the mid-2020s with a value of 2A $50,000 small car is also planned to use the battery.
According to Drew Baglino, Tesla's head of batteries, Tesla plans to install eight production lines at its Texas factory in two phases, with the last four lines to be operational by the end of 2024.
Sources believe that once stable production is achieved on one production line, Tesla will be able to expand the production scale of the 4680 by leaps and bounds. They say Tesla has worked hard to build up its expertise so that it doesn't suffer from defects in the first round of production. It's a time-consuming process, but once the bottleneck is broken and stability is established, the rate at which it grows skyrockets.
However, it is not easy to replicate existing technology from one production line to another. Batteries produced on mature lines have only about 5% scrap rate, but as each new line comes online, the scrap rate could increase to 30% to 50% and stay at that level for months, according to a source.
Another source said that Tesla's cathode dry coating method proved to be no faster than the old wet process, despite the scrap rate having dropped to 10 to 20 percent. According to sources, Tesla is working to mix cathode materials, including lithium, manganese and nickel, with binders and glue them to metal foil to produce cathodes without the use of water.
Two of the people said the process only worked in a few cases, but when Tesla tried to scale up, it generated a lot of heat that caused the adhesive to melt. One of the *** believes that the adhesive is Teflon, commonly known as Teflon. A person familiar with the matter said that after the adhesive melts, soon everything will turn into a large lump of slimy mud.
The machines used to coat metal foil to produce battery electrodes are also a headache for Tesla, which is trying to coat multiple magnetic foils with active battery materials at high speed at the same time in order to speed up battery production.
This requires the use of wide rollers and the exertion of enormous forces to press the material onto the tape. However, due to the wide size of the rollers, it is a challenge to apply pressure evenly. If the pressure is applied unevenly, the electrode surface and thickness will be uneven and will have to be scrapped.
Specifically, it's about building a data infrastructure around Tesla's battery development, manufacturing, and field use, as in some cases, defects are hidden in the coating and don't become apparent until months later, a person familiar with the matter said.
In other words, Tesla doesn't know which cells are good and which need to be scrapped, the source said. Speaking at a battery conference in March 2023, Baglino said Tesla was still building a new quality verification system to be able to weed out batteries with defective coatings.
Tesla released the 4680 battery in 2020. At the beginning of R&D, Musk believed that battery manufacturing was too inefficient, and Tesla could reinvent the battery manufacturing process, abandon conventional practices, reduce costs by 50%, and create smaller, greener factories. Mass production of the 4680 battery was originally planned to begin in 2021, but it will not be mass-produced on a small scale until mid-2023.
Compared with the current mainstream 2170 battery cells, Tesla chooses a large cylindrical structure to increase the proportion of energy substances in a single battery, thereby improving the energy density of the battery. This design balances manufacturing efficiency with cost. It will take some time for this process to be perfected.
This is reminiscent of a popular saying of the American ** team during World War II: "We will do the difficult things immediately." The impossible takes time. ”