Factorial Energy, a US-based solid-state battery developer, and SK On, a South Korean battery manufacturer and supplier to Hyundai Motor Group, have signed a Memorandum of Understanding (MoU) to explore large-scale production of solid-state batteries. The partnership aims to use existing manufacturing infrastructure rather than building dedicated factories.
Solid-state batteries are considered a next frontier in automotive technology, offering higher energy density, longer driving ranges, and faster charging than traditional lithium-ion batteries. However, manufacturing them at scale remains challenging due to issues with solid electrolyte conductivity, cracking, and high costs.
SK On, which supplies EV batteries to Hyundai Motor Group, Ford, and Volkswagen, holds over 200 GWh of annual production capacity globally, including about 100 GWh in the US. The main priority of the partnership is to assess whether SK On's facilities can support solid-state battery production.
Factorial's solid-state battery technology, called FEST. Stellantis stated that Factorial's 77Ah FEST cells achieved an energy density of 375 Wh/kg over more than 600 cycles. The cells also achieved ultra-fast charging from 15% to 90% in 18 minutes and maintained performance in extreme temperatures from -22°F to 113°F (-30°C to 45°C).
Factorial's solid-state batteries are being tested by several automakers. Mercedes-Benz drove a modified EQS over 745 miles (1,200 km) using Factorial's cells, and Mercedes' technology boss Markus Schäfer called the technology a potential 'gamechanger' for EVs. Stellantis has integrated the cells into its STLA Large platform, powering a Dodge Charger Daytona prototype. Additionally, Factorial is working with Karma, Hyundai, and Kia for commercialization.
The partnership with SK On follows. Factorial and SK On plan to pool their resources and mass-produce solid-state batteries on existing battery lines, targeting mobility, high-performance markets, and energy storage.