Two EV Battery Leaders Partner to Scale Solid-State Breakthrough

SK On and Factorial Energy are joining forces to advance one of the electric vehicle industry’s most anticipated technologies: solid-state batteries. The two companies signed a memorandum of understanding (MOU) on Wednesday to bring Factorial’s solid-state battery technology into SK On’s global manufacturing ecosystem, with the goal of accelerating commercialization and large-scale production.

Solid-state batteries have attracted significant attention because they offer the potential for higher energy density, longer driving ranges, faster charging times, and improved safety compared to conventional lithium-ion batteries. However, the technology still faces several barriers to mass production. Developing a solid electrolyte that delivers high conductivity while remaining durable enough to avoid cracking or degradation continues to be a major challenge. Manufacturing costs and scalability also remain key obstacles.

The new partnership will focus on evaluating how SK On’s battery manufacturing facilities can support the production of future solid-state battery cells. By combining Factorial’s FEST (Factorial Electrolyte System Technology) platform with SK On’s battery development and manufacturing expertise, the companies aim to determine the most effective path toward commercial-scale production.

“A battery breakthrough only matters if it can be manufactured at scale,” said Factorial CEO Siyu Huang. She added that SK On’s manufacturing footprint includes some of the world’s most advanced battery production facilities and that the company’s expertise will play an important role in integrating solid-state battery technology into global production systems.

Factorial’s high-energy-density battery technology is designed to enable lighter, smaller, and more efficient energy storage solutions for electric vehicles, energy storage systems, defense applications, and other industries. The company recently began testing its FEST solid-state battery cells in North America through a collaboration with Stellantis. The cells were integrated into Stellantis’ STLA Large platform and used to power a Dodge Charger Daytona prototype.

According to Stellantis, Factorial’s 77Ah FEST cells achieved an energy density of 375 Wh/kg across more than 600 charge cycles. The batteries also demonstrated rapid charging capability, charging from 15% to 90% in approximately 18 minutes, while maintaining performance in temperatures ranging from -22°F to 113°F (-30°C to 45°C). The cells also achieved discharge rates of up to 4C.

Factorial continues to expand its relationships with major automakers, including Mercedes-Benz, Hyundai, Kia, and Stellantis. Last year, Mercedes-Benz tested Factorial’s solid-state battery technology in a modified EQS that traveled more than 745 miles (1,200 km). Mercedes Chief Technology Officer Markus Schäfer has described the technology as a potential “gamechanger” for the EV industry.

SK On enters the partnership with substantial manufacturing resources. The company currently supplies EV batteries to Hyundai Motor Group, Ford, and Volkswagen and operates more than 200 GWh of annual battery production capacity worldwide, including approximately 100 GWh in the United States.

The announcement follows another major collaboration for Factorial. In December, the company partnered with South Korea’s POSCO FUTURE M to develop advanced materials for next-generation all-solid-state batteries, further expanding its efforts to bring the technology closer to commercial deployment.