The 4680 battery packs that Tesla now places in its Model Y are only halfway to the stated goal of a 50% cost reduction compared to conventional batteries. Tesla is yet to master mass dry electrode production to hit the full 4680 cell potential, and it has now hired a solid-state battery specialist dedicated to the issue.
During Battery Day 2020, Tesla announced a larger 4680 cell that was supposed to go into EV power packs that would cost half of what its current 2170 batteries do. The structural 4680 battery pack that Tesla started installing in the Model Y assembled at Giga Texas, however, reportedly costs only US$3,600 less than the 2170 cell equivalent. Those savings are relatively modest compared to the big 4680 promises because they only come from the physical advantages of the 4680-type battery, rather than some revolutionary chemistry breakthrough.
The 4680 cells, which are way larger than the 2170 ones, can serve as structural support and are installed as an integral part of the vehicle’s body in a direct cell-to-pack arrangement. This increases volume utilization drastically and requires way fewer welding points for the 830 (rather than 4,400) cells, resulting in a much lighter battery. The downside is that the Model Y’s 4680 structural pack is now sealed as part of the chassis and it is near impossible to repair individual cells.
Tesla now has to master the harder part of the promised 4680 battery cost savings – producing the electrodes with a dry coating method – if it wants to reach the coveted US$5,000 or so expenditure per Model Y pack. According to industry analysts, this would allow Tesla to slash the Model Y price further by US$5,280.
The standard wet coating applied to the 4680 cathode now is a long and messy process that requires a lot of energy and the application of toxic chemicals. The dry coating method, on the other hand, is safer, cheaper, and can be done in a much smaller facility.
In 2019, Tesla acquired the dry process startup Maxwell Technologies which led to its flamboyant 4680 Battery Day presentation on the 4680 cells potential. It, however, failed to replicate the method on a mass production scale and Tesla is now externally hiring specialists to help it master the process.
Tesla has reportedly poached 24M’s VP of advanced manufacturing Matt Tyler who has worked on the development of a semi-solid battery for the last six years. One of 24M’s breakthroughs is the invention of “an ultra-thick SemiSolid cathode made up of advanced cobalt-free, nickel-free sodium cathode active material.”
That’s in the ballpark of the dry cathode coating process that the world’s largest EV maker is looking to manufacture on a big scale. Tesla leaves little doubt about the reason it hired Mr. Tyler who now holds the unequivocal position “Director of Dry Electrode Development” at its 4680 pioneering facility in the Fremont factory.
Tesla was hopeful that it will achieve a dry electrode production breakthrough by the end of 2022, but that didn’t materialize, so it now seems determined to spearhead the process this year. After all, scaling production of as cheap as possible 4680 cells will be pivotal for retaining its enviable profit margins amidst an EV price war of its own making.
Tesla recently announced a huge 100 GWh 4680 battery capacity expansion of the Nevada Gigafactory that may net it US$3.5 billion in federal tax credits annually. If it solves the mass dry cathode production conundrum by then, and with the government’s subsidies in place, Tesla has every chance to become the manufacturer of the cheapest batteries just as it is now the most cost-effective EV maker.
Daniel Zlatev – Tech Writer – 654 articles published on Notebookcheck since 2021
Wooed by tech since the industrial espionage of Apple computers and the times of pixelized Nintendos, Daniel went and opened a gaming club when personal computers and consoles were still an expensive rarity. Nowadays, fascination is not with specs and speed but rather the lifestyle that computers in our pocket, house, and car have shoehorned us in, from the infinite scroll and the privacy hazards to authenticating every bit and move of our existence.