Mercedes sees 'no issue in design of Farasis battery' behind Korean EV explosion

Uwe Keller, head of battery development at Mercedes-Benz AG, explained that the company is determined to shed its reliance on battery makers by developing its own EV batteries.

Uwe Keller, right, head of battery development at Mercedes-Benz AG, and Carsten Breckner, head of powertrain procurement and supplier quality, talk during an interview with the Korean press at the automaker's headquarters in Stuttgart, Germany, on Oct. 21. [MERCEDES-BENZ KOREA]

[INTERVIEW]

STUTTGART, Germany — After facing fierce backlash for using batteries from an obscure Chinese company in an EV that caused a massive explosion incident in Korea, Mercedes-Benz is exerting desperate efforts to secure its own capabilities to develop EV batteries that guarantee safety in a bid to shed reliance on battery makers.

It comes as the German automaker believes the cause of the EV fire had nothing with the "battery design issue," and Farasis Energy, the battery supplier for the problematic EQE sedan, has proven its quality through strict criteria.

“Our target is to have our own Mercedes-Benz cell DNA and industrialize it with our suppliers,” said Uwe Keller, head of battery development at Mercedes-Benz AG, during a recent interview with the Korea JoongAng Daily at the automaker's headquarters in Stuttgart, Germany, on Oct. 21.

“In the long term, we are developing all solid-state batteries that have intrinsic cell safety due to the absence of fluid electrolytes, but in the mid-term, we have a lot of steps in order to improve safety measures with the lithium-ion batteries,” Keller said. “Having bigger thermal barriers between the cells can be one of the technologies to prevent thermal propagation.”

Mercedes-Benz Korea CEO Mathias Vaitl talks during an interview with the Korean press at the automaker's headquarters in Stuttgart, Germany, on Oct. 21. [MERCEDES-BENZ KOREA]

Keller’s emphasis on securing the company's own battery technologies comes after it was made public that Farasis Energy, established in 2009, has a big recall record over battery defects. The EV explosion occurred on Aug. 1 in an underground parking garage in Incheon, damaging as many as 880 nearby cars and cutting the electricity and water supply to some 1,600 households in the apartment complex.

“We can transfer this knowledge to our battery cell supplier, or we do a joint venture or we become a shareholder, as we are with France’s Automotive Cell Company together with Stellantis and Total Energy,” Keller said.

A Mercedes-Benz engineer tests batteries at its eCampus, a research center dedicated to the development of batteries in Stuttgart, Germany. [MERCEDES-BENZ KOREA]

Mercedes in July newly opened an eCampus in Stuttgart dedicated to battery research and development that can ultimately reduce fire risks and cut costs. Around 100 researchers and engineers test new technologies on tens of thousands of batteries every year to develop solid-state batteries or silicon-based anodes.

The second phase of construction of the eCampus is expected to finish by the end of the year, where Mercedes will have facilities to examine and prove the technologies ahead of mass production.

Mercedes-Benz engineers test batteries at its eCampus, a research center dedicated to the development of batteries in Stuttgart, Germany. [MERCEDES-BENZ KOREA]

When asked about the reason why Mercedes chose such a little-known battery company as a major supplier, Keller emphasized that Farasis passed all the strict quality standards of the German automaker, adding that there was no "battery design issue" related to the incident.

“Farasis is a smaller company compared to others, but they've also developed a lot and we have constantly surveyed their quality performance,” Keller said. “We have done all the selection checks, we have done the continued series production checks and we do also have regular visits to their plant. So in that sense, no exception was made and the same high quality standards were applied also when a few years ago and up to the present date in our deal with Farasis.”

“How this battery is designed in the cell and the cell module design is a standard design also coming in with many other automakers as well, so I wouldn't say that it's an issue with the battery design,” Keller said. “For example, we were criticized for having the coolant pipe outside the battery pack [after a video of the EQE battery was disclosed], but actually that was done purposely because we wanted to separate high voltage and water to increase safety based on our experience."

Mercedes in August revealed that thirteen of the 16 EV models on Korean roads are powered by Farasis Energy batteries, including three of four EQE models and the upper-level EQS 350.

From that perspective, “we are very open and we actually support Korea’s push to set higher standards,” Keller said, adding that he is “in a lot of discussion with each government on regulation issues, especially in Korea, about new standards.”

Fueled by the Mercedes EV explosion, the Korean government is set to implement an EV battery certification system that requires automakers to get an examination of the EV batteries before they release EVs in the Korean market. The new policy is expected to apply to Mercedes starting from 2026 with no grace period.

“We feel very bad about what happened in Korea and we're taking that very seriously,” Keller said. “Mercedes-Benz is fully collaborating with authorities and we provide all of our efforts and knowledge on all sides, from the production and inspection side, to further this investigation.”

BY SARAH CHEA [chea.sarah@joongang.co.kr]