Factorial Energy Inc. announced on September 17, 2026, that it has formed a strategic partnership with Mitsui Kinzoku Company, Limited to support the industrialization of Factorial’s Solstice all-solid-state battery platform.
Mitsui Kinzoku produces sulfide-based solid electrolytes for all-solid-state batteries. Its A-SOLiD sulfide solid electrolyte was unveiled in 2016 and is advancing toward mass production at a dedicated plant in Saitama, Japan. The company also produces ultra-thin copper foil and has an estimated 90% share of the semiconductor market for that material.
Under the collaboration, Factorial will remain the fabless developer of the Solstice platform. Its responsibilities include cell design, process development, supply chain qualification, production-line integration and manufacturing validation. Mitsui Kinzoku will contribute its materials and manufacturing expertise, including its sulfide electrolyte technology.
Solstice is a sulfide-based all-solid-state battery platform intended for mobility, aerospace and other applications. According to Factorial, the platform provides high energy density and improved thermal stability. Its proprietary dry-cathode process is designed to support more cost-effective manufacturing.
Mitsui Kinzoku said the partners aim to accelerate the development of next-generation batteries by combining its materials and manufacturing capabilities with Factorial’s battery technology. Factorial CEO Siyu Huang said the electrolyte technology would support efforts to move Solstice toward commercial deployment.
The agreement follows Factorial’s first commercial orders for passenger vehicle applications in January and aerospace applications in July. The company has also received strategic investments from IQT and POSCO Future M and expanded its automotive and industrialization partnership programs.
Source: globenewswire.com
