Factorial Energy Inc. (NASDAQ: FAC) announced a strategic partnership and joint development agreement with Mitsui Kinzoku Company Ltd. to support the commercialization of its Solstice all-solid-state battery platform.
Under the agreement, Factorial will lead cell design, process development, supply chain qualification, line integration and manufacturing validation, while Mitsui Kinzoku will contribute materials expertise, specifically producing sulfide-based solid electrolytes for all-solid-state batteries. Factorial’s Solstice platform combines sulfide-based solid-state technology with dry-cathode processing.
Mitsui Kinzoku has experience in the technology dating to 2016, when it unveiled its A-SOLiD sulfide solid electrolyte at a dedicated plant in Saitama. The company also holds an estimated 90% share of the semiconductor market for ultra-thin copper foil.
Dr. Kiyotaka Yasuda, senior executive officer at Mitsui Kinzoku, said the partnership aims to accelerate next-generation battery development by combining Mitsui Kinzoku’s materials and manufacturing expertise with Factorial’s advanced capabilities. Factorial CEO Siyu Huang added that Mitsui Kinzoku’s foundational electrolyte technology brings critical materials expertise as Solstice moves toward commercial deployment.
Factorial has seen recent momentum: it secured its first commercial orders for passenger vehicles in January and its first aerospace orders in July. The company listed on Nasdaq under the ticker FAC in June 2026.
Factorial’s investor base includes strategic investments from IQT and POSCO Future M, along with backing from major automakers Mercedes-Benz, Stellantis, Hyundai and Kia.
