Two solid-state EV battery leaders are joining forces to scale the breakthrough tech. SK On and Factorial Energy announced a new alliance that will focus on bringing solid-state batteries to the masses. The South Korean battery giant and US-based startup signed a Memorandum of Understanding on Wednesday to pool resources toward mass-producing solid-state cells for electric vehicles.
SK On and Factorial team up on solid-state EV batteries
Solid-state batteries have the potential to deliver higher energy density, longer driving ranges, and faster charging than traditional lithium-ion batteries, but manufacturing them at scale remains a challenge. Finding a solid electrolyte that's conductive and won't crack or break still poses a challenge, and manufacturing them can be expensive.
South Korea's SK On and US-based Factorial Energy will pool their resources in an effort to manufacture solid-state batteries at scale. The two signed an MOU (Memorandum of Understanding) on Wednesday to bring Factorial's solid-state cell technology to SK On's global manufacturing network. For more on the solid-state battery area, see Electrek's coverage.
One of the main priorities of the new partnership is to assess whether and how SK On's manufacturing facilities and battery plants can support the development of future solid-state batteries. Under the new alliance, the two will work together, using Factorial's FEST solid-state battery tech and SK On's battery and manufacturing expertise, to determine whether it's feasible.
A battery breakthrough only matters if it can be manufactured at scale, said Factorial's CEO, Siyu Huang, after announcing the partnership with SK On. Huang added that SK On's manufacturing footprint spans some of the world's most advanced battery facilities, and their expertise will be critical in shaping how solid-state battery technology integrates into global production ecosystems.
Meanwhile, Factorial's high-energy density batteries enable smaller, lighter, and more efficient solutions for electric vehicles, energy storage, and defense applications.
Manufacturing the breakthrough batteries at scale
Last month, Factorial announced it had begun 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. Stellantis said last year that Factorial's 77Ah FEST cells achieved an energy density of 375 Wh/kg over more than 600 cycles.
The cells delivered ultra-fast charging from 15% to 90% in 18 minutes while maintaining performance in extreme temperatures ranging from -22°F to 113°F (-30°C to 45°C). Factorial's solid-state cells achieved a discharge rate of up to 4C.
Factorial is working with major automakers, including Mercedes-Benz, Hyundai, Kia, and Stellantis, to commercialize solid-state EV batteries. Last fall, Mercedes-Benz drove a modified EQS over 745 miles (1,200 km) using Factorial's solid-state battery cells. Mercedes' tech boss, Markus Schäfer, is already calling Factorial's battery tech a potential gamechanger for EVs.
SK On, on the other hand, supplies EV batteries to Hyundai Motor Group, Ford, and Volkswagen. The battery giant has over 200 GWh of annual production capacity globally, including about 100 GWh in the US alone.
The energy density advantage of solid-state design means future EVs could travel significantly farther on a single charge while battery packs shrink in size and weight. As demand grows for longer-range electric trucks and buses, the SK On-Factorial alliance positions both companies to capture early market share in the segment. Several industry observers expect early production models to emerge from the partnership within 18 to 24 months.
The new alliance comes after Factorial announced a partnership with South Korea's POSCO FUTURE M to develop materials for all-solid-state batteries last December.
Industry impact and implications
The partnership signals that the solid-state battery transition, once expected only in the distant future, is now entering the real-world production phase in 2026. After decades of research, solid-state battery technology is entering real-world production, with major manufacturers racing to commercialize what could be the biggest leap in energy storage since lithium-ion cells were invented. For related category coverage, see battery tech articles on this site.
Analysts say the SK On-Factorial alliance could accelerate the timeline for solid-state EVs, potentially bringing true solid-state vehicles to market within the next few years rather than the late 2020s projections that have dominated industry forecasts. The collaboration combines SK On's manufacturing scale with Factorial's novel cell chemistry, creating a model that other battery producers may seek to replicate. If the feasibility assessment proves successful, the first solid-state battery EVs could reach showrooms as early as 2027.
For consumers, the implications are substantial: solid-state batteries could eventually deliver driving ranges exceeding 800 miles on a single charge, charging times measured in minutes rather than hours, and improved safety by eliminating the flammable liquid electrolytes used in current lithium-ion designs.
Challenges ahead
Despite the progress, substantial hurdles remain. Manufacturing solid-state batteries at scale has proven far more difficult than laboratory prototypes suggest. The companies will need to overcome challenges related to electrolyte stability, interfacial resistance between electrode and electrolyte, and cost reduction to make the technology competitive with established lithium-ion chemistry.
Moreover, the partnership will need to manage complex supply chains, secure raw materials for solid-electrolyte components, and meet the rigorous safety and durability standards required by automotive customers. The MOU's feasibility assessment phase will be crucial in determining whether the technical and economic barriers can be cleared within a reasonable timeframe.
Conclusion
The SK On-Factorial Energy partnership represents one of the most substantial developments in the solid-state battery story this year. By combining established manufacturing expertise with novel cell chemistry, the two companies have created a potentially viable path toward mass-market solid-state EVs. While challenges remain, the pace of advancement in 2026 suggests that the holy grail of battery technology — batteries that are safer, denser, and faster to charge than today's lithium-ion cells — may finally be within reach, with the SK On-Factorial partnership serving as a definitive milestone on the path toward mass-market adoption for the industry. The partnership's success could signal aaccelerated industry-wide transition to solid-state chemistry in the coming years.
Tech Desk | battery, solid-state, EV, SK On, Factorial Energy, renewable energy Keywords: solid-state battery, electric vehicle, energy density, battery technology, SK On, Factorial Energy, FEST battery, sustainable transport
