Tesla is in advanced negotiations with the Chinese battery manufacturer CATL about the use of batteries without cobalt. That writes Reuters based on sources. These batteries would be used in the Shanghai Tesla factory, where only Model 3s are currently made.
According to sources familiar with the matter, Tesla has been in talks with CATL about this for more than a year. The goal is to achieve batteries that are cheaper than current batteries by “a double-digit percentage,” Reuters writes citing a source.
This cost saving is achieved because cobalt is a relatively expensive metal. Most of it is mined and extracted in the Democratic Republic of Congo as a by-product of copper smelting, which also involves child labor and poor conditions for the miners. A few years ago, the price of cobalt skyrocketed. That price has now been lowered for a while, but it remains a relatively expensive metal, which is expected to become more expensive in the coming years.
The batteries that Tesla would purchase from CATL and use in the Shanghai-made Model 3s and later the Model Y are lithium iron phosphate batteries. This type of battery is known for its thermal and chemical stability, which is particularly important because cobalt is used for the stability of the cathodes. This makes it possible to maintain the layered structure of cathodes well, which leads to a good service life, a short charging time and a large energy potential.
A disadvantage of lithium iron phosphate batteries is their relatively lower energy density, but CATL would at least partly overcome this with their cell-to-pack technology. The company unveiled the technology in September last year. This makes it possible, according to CATL, to skip the process of merging a cluster of cells into modules so that they can be directly assembled into packs. In traditional batteries, a group of modules forms a pack. By integrating the cells directly into packs, the process of modules can be skipped and, according to CATL, a gain of ten to fifteen percent can be achieved in terms of energy density. The costs for parts can also be reduced by forty percent. Based in the eastern Chinese city of Ningde, CATL is one of the largest lithium-ion battery manufacturers in the world.
Tesla already uses batteries with relatively little cobalt in its Model 3. Last year, the head of the Center of Excellence for Batteriezellen at Volkswagen indicated that the cathodes of the batteries contain no more than 2.8 percent cobalt. For comparison: with Volkswagen’s upcoming electric hatchback, the ID.3, that percentage is between twelve and fourteen. Elon Musk from Tesla gave already indicated in June 2018 that the next generation of batteries that the company installs in its car will no longer contain cobalt at all.