Mitsui Kinzoku Partners with Factorial to Advance All-Solid-State Batteries

Mitsui Kinzoku, a leading Japanese materials company, has entered into a strategic partnership with Factorial Energy Inc., a global innovator in solid-state battery technology, to accelerate the commercialization of all-solid-state batteries. The collaboration, announced on September 17, 2026, is expected to significantly boost the global scale-up of Factorial's Solstice™ platform.

Mitsui Kinzoku, known for its foundational expertise in sulfide-based solid electrolytes, will leverage its advanced materials and manufacturing technologies to support Factorial's efforts. The company is already a global leader in ultra-thin copper foil, with an estimated 90% market share in the semiconductor industry. This partnership positions Solstice™ at the forefront of the industry's push towards commercializing all-solid-state batteries.

Dr. Kiyotaka Yasuda, Senior Executive Officer and General Manager of Mitsui Kinzoku's Business Creation Division, expressed enthusiasm about the collaboration. "Batteries are a key technology for realizing an electrified society, but significant technical challenges remain. By combining Mitsui Kinzoku's long-established expertise with Factorial's advanced technological capabilities, we aim to accelerate the realization of next-generation batteries."

Factorial Energy Inc., backed by strategic investments from IQT and POSCO Future M, is a leading American solid-state battery innovator. The company's proprietary Solstice™ platform, which includes high energy density and improved thermal stability, is designed to meet the energy demands of the next era of mobility, aerospace, and physical intelligence. Factorial's CEO, Siyu Huang, emphasized the importance of collaboration in battery innovation. "Battery innovation can't be done by one single company. It's driven by the entire supply chain and, increasingly, by an entire industry coalition."

The partnership builds on Factorial's recent momentum, including its first commercial orders for passenger vehicles and aerospace applications, as well as its listing on the Nasdaq in June 2026. Factorial's Solstice™ platform, which includes proprietary dry-cathode processing, is expected to deliver cost-effective manufacturing and enhanced performance across various applications.

Mitsui Kinzoku's involvement in the partnership underscores the company's commitment to advancing battery technology. Dr. Yasuda added, "We believe it is necessary to go beyond the extension of existing technologies and take on the challenge of creating new value. Mitsui Kinzoku's foundational electrolyte technology brings critical materials expertise to our work to move Solstice™ toward commercial deployment."

This collaboration is seen as a significant step towards the widespread adoption of all-solid-state batteries, which are expected to offer improved safety, higher energy density, and longer lifespans compared to traditional lithium-ion batteries. The partnership positions both companies at the forefront of this emerging technology, with the potential to revolutionize the energy landscape and support the transition to a more sustainable future.