Factorial Energy and Mitsui Kinzoku plan to jointly advance the industrialization of solid-state batteries. The collaboration centers on Factorial’s sulfide-based Solstice platform. Mitsui Kinzoku will contribute its solid sulfide electrolyte technology.
The partnership primarily targets the transition from development to industrial manufacturing. According to Factorial, the company will remain responsible for cell design and process development. Its role also includes supply chain qualification, line integration, and manufacturing validation.
Sulfide Electrolyte for Factorial’s Solstice Battery
Mitsui Kinzoku has been developing sulfide electrolytes for solid-state batteries for several years. The company introduced its A-SOLiD electrolyte in 2016. A dedicated production facility is currently being established in Saitama, Japan.
The Japanese company’s materials expertise will now be incorporated into Factorial’s Solstice platform. Factorial cites high energy density and improved thermal stability as development targets and characteristics of the platform.
Factorial Moves Ahead With Commercialization
Factorial reported its first commercial orders for passenger vehicle and aerospace applications in 2026. IQT and POSCO Future M have also invested in the company. Factorial listed on Nasdaq under the ticker FAC in June 2026.
Before the listing, Factorial had tested its battery technology with companies including Mercedes-Benz and Stellantis.
