On May 12, 2025, Sepion Technologies announced plans to build a lithium-ion battery separator manufacturing facility in West Sacramento. The announcement follows the company’s opening of an operational prototype facility in 2023 and is supported by a $17.5 million grant from CALSTART and the California Energy Commission’s PowerForward: ZEV Battery Manufacturing Grant program.
The planned facility aims to address supply chain gaps for battery separators in North America. According to a recent McKinsey report cited by Lawrence Berkeley National Laboratory, domestic production of battery separators is expected to fall short of demand by more than half by 2030, making the region reliant on imports. Low-cost, high-performing separators are considered critical for improving battery performance, safety, and lifespan.
Sepion Technologies was founded in 2015 by Peter Frischmann and Brett Helms after developing a nanoporous membrane known as a polymer of intrinsic microporosity (PIM) at Berkeley Lab’s Molecular Foundry and the Department of Energy’s Joint Center for Energy Storage Research. The PIM technology allows charge-carrying ions to move through batteries while blocking polysulfide ions that can cause dendrite formation and short circuits. The company reports that its membrane can cost significantly less than ceramic alternatives while permitting higher power output.
After initial development efforts focused on lithium-sulfur batteries, Sepion pivoted toward lithium-metal batteries based on industry feedback. The company has since received multiple grants—including $150,000 and $1 million SBIR/STTR awards, a $3.5 million ARPA-E IONICS grant with partner 24M, a $16 million Series A funding round in 2021, and a $9 million ARPA SCALEUP award in 2022—to advance its technology.
Currently employing 28 people at its Alameda prototype facility with an annualized capacity of up to 500,000 square meters of coated separator and one megawatt-hour of prototype cells, Sepion plans for the new West Sacramento plant to initially produce enough material for approximately 50,000 electric vehicles per year. The company intends to scale production further after operations begin.
Sepion has also received industry recognition as one of Chemical & Engineering News’s Top Ten Startups to Watch in 2022 and was named “Best Commercialization Venture” at NREL’s Industry Growth Forum in 2025. For more information about Sepion Technologies’ plans and background, visit the Lawrence Berkeley National Laboratory website.
