Tesla has a vision it believes will lead it to the promised land of electric vehicle success. It’s called the 4680 battery cell — so named because it is 46 millimeters in diameter and 80 millimeters tall. According to what Elon Musk told the world at Battery Day in 2020, the 4680 battery will unlock a cornucopia of benefits. It will have a higher energy density than any cylindrical battery cells currently in commercial production, which will enable longer range electric vehicles. It will also slash battery manufacturing costs by 50% or more, leading the way to more affordable electric cars.
The key to the 4680 battery isn’t its size, it’s the manufacturing process used to make it. As Musk and Tesla envision things, the new battery will be manufactured using a new dry electrode process. In today’s lithium-ion batteries, both the anode and the cathode are coated with a wet slurry of chemicals during manufacturing. That coating must be dried before the process continues, which requires a large amount of space in the factory and the use of copious quantities of energy. Since that slurry is composed of chemicals you don’t want escaping into the atmosphere or the groundwater, they must be recovered as part of the drying process.
If the wet part of the process can be eliminated, the size of a battery factory shrinks considerably, the amount of energy needed to manufacture batteries is dramatically reduced, and there are no harmful chemicals to be recovered. The end result is cheaper batteries, something the world desperately needs if it is to transition to electric transportation. You might think this is child’s play for a company that has access to some of the world’s most talented engineers — after all, Musk’s other company, SpaceX, has trained rockets to fly backwards and land on a barge floating on the ocean — but the reality is that perfecting the dry coating process is taking longer than expected.
The story began in 2019, when Tesla bought Maxwell Technology, a company that specialized in dry coatings for supercapacitors. Musk, of course, has boldly promised the 4680 batteries would be in production soon and, in fact, they are being installed in some Model Y vehicles at the Gigafactory in Austin, Texas. But while those batteries may look different from the 2170 batteries currently used in most of Tesla’s production cars, they use the same tried and true wet slurry manufacturing process. While there are some benefits — they are being packaged into structural battery packs that are somewhat less heavy — the benefits expected to flow from perfecting the dry coating process have yet to be realized.
Tesla 4680 Production Challenges
Panasonic is running a pilot 4680 production line at its Wakayama factory in Japan and plans to start volume production later in the fiscal year that ends in March 2024. It is also building a battery factory in Kansas where CTO Shoichiro Watanabe says the company will focus initially on 2170 cells but shift to 4680 production eventually. Last year, LG said it planned to open a new 4680 production line at its Ochang plant in Korea in the second half of 2023.
Meanwhile, Tesla is experimenting with the dry coating process at a pilot factory in Fremont, California. Sources tell Reuters the first-generation 4680 cells built in Fremont have yet to achieve the goal the company has set for energy density. To date, the process to dry coat the anodes is on track, but the company is still having issues with dry coating the cathode, which is where the most significant gains are expected to be made.
Getting the 4680 battery right is essential to getting the long-awaited Tesla Cybertruck into production. Reuters says the company has considered using traditional 2170 batteries for that vehicle as well as LFP batteries but has decided to focus instead on using dry coated 4680 cells. The lack of availability of those cells is said to be the principal reason the Cybertruck is not yet in volume production.
To move the dry coating technology forward, Reuters reports Tesla has signed agreements with China’s Ningbo Ronbay New Energy and Suzhou Dongshan Precision Manufacturing to help trim materials costs as it ramps up production of 4680 battery cells in the United States, according to the sources who asked not to be named. Tesla also has signed a deal with Korea’s L&F Co to supply high-nickel cathodes that could increase the energy density of its 4680 cells, one of the sources said. Tesla plans to use a cathode with more than 90 percent nickel in the next generation of 4680 cells, two sources told Reuters.
When and if Tesla cracks the dry coating conundrum, it intends to manufacture 4680 batteries at or near most of its manufacturing facilities worldwide while also relying on partners like LG Energy Solution and Panasonic to supply them to the company. Elon Musk has said Tesla will be manufacturing 20 million electric cars a year by 2030 but it will need to offer less expensive models if it is to reach that goal. The dry coated 4680 battery is a critical part of reducing manufacturing costs so the company can make those lower priced models profitably.
With Musk, promises are always to be taken with a grain of salt. Tesla often lags behind his pie in the sky pronouncements by years, but it typically gets there eventually. Older readers may recall hearing stories from World War II veterans who prided themselves on reaching seemingly insurmountable objectives by saying, “The difficult we do right away. The impossible takes a little longer.”
Morgan Stanley has been a staunch supporter of Tesla for many years. Recently it said in a research note, “While execution risk remains and many details are unknown, Tesla’s impact on the global battery industry may still be underestimated.” That may be an understatement. The company is charting new pathways to lower the costs of production by simplifying the production process. Giant castings — never before used in volume manufacturing — can make parts in minutes that usually require hours of stamping and welding. The company is working to eliminate as many wires as possible as part of that simplification process. It also steadfastly refuses to offer a blizzard of models and options because complexity adds costs.
The jury is still out on Tesla. There remains the possibility that the company could flame out as mainstream manufacturers overcome its “first mover” advantage with products that are better and cheaper, but that seems a long shot at this point. We often speculate about which companies will survive the EV revolution and which will not, but nobody here at CleanTechnica ever puts Tesla on the list of possible failures.
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Source: Clean Technica