The race to squeeze more miles out of electric vehicles just got another contender—this one operating at the nanoscale.
Sepion Technologies, a Berkeley spinout working on ultra-thin polymer coatings for lithium-ion batteries, closed a $10 million Series B round on March 26, 2026, pulling in strategic backing from two materials industry heavyweights as it transitions from lab validation to commercial production. For a sector where incremental improvements can mean billions in market value, the company's pitch is straightforward, if ambitious: lighter batteries that hold more charge, made on equipment automakers already own.
Fine Structure Ventures led the round. Joining them were W.L. Gore & Associates and Syensqo Ventures—both making their first bets on the Alameda, California-based startup. The duo represents exactly the kind of strategic capital battery upstarts need: deep pockets, deeper Rolodexes, and manufacturing know-how that spans continents. VoLo Earth Ventures, Chailease, Catalus Capital, Impact Science Ventures, and ACVC Partners returned from earlier rounds, with MTM Venture Partners coming in fresh.
The funding arrives as Sepion navigates that precarious valley between pilot production and the purchase orders that actually pay bills. It's a crossing many hardware startups never complete.
A Coating That Fits—Literally
Sepion's technology centers on polymer films less than 200 nanometers thick, designed to replace the ceramic coatings currently standard in EV battery separators. Think of separators as the critical membrane keeping a battery's positive and negative sides from touching—essential, but until recently, not a component anyone spent much time optimizing.
The company claims its coatings can shave up to 8 kilograms off a vehicle's weight while boosting energy density and reducing the self-discharge that quietly drains parked EVs. That might not sound dramatic, but in an industry where range anxiety remains a dealbreaker for many buyers, every percentage point matters.
Perhaps more importantly for adoption, Sepion says its SEPION POWER and SEPION SHIELD product lines work as drop-in replacements. No retooling assembly lines. No redesigning battery packs. Compatible with NMC, LFP, and the manganese-rich cathode chemistries gaining traction in next-generation cells.
"We're delivering a step-change upgrade that works on existing lines and is ready for commercial scale today," CEO and co-founder Peter Frischmann said in a statement—though the proof, as always, will be in whether battery manufacturers actually integrate the technology at volume.
From Qualification Hell to Revenue (Maybe)
Sepion finds itself in the middle of what battery industry insiders grimly call "qualification hell"—the extended testing and validation process global manufacturers require before committing to new materials. The company is currently supporting multiple programs with what it describes as leading battery makers, and has already produced coated separators on commercial lines for late-stage customer testing.
That's promising, though the gap between customer trials and signed contracts remains wide. Battery supply chains move slowly, weighted by safety concerns and razor-thin margins.
The fresh capital will scale polymer production in the U.S. and fulfill what Sepion characterizes as commercial purchase orders already in hand. The company also plans to shore up quality systems and operations—the unglamorous but critical work of ensuring every batch performs identically.
"The market demand for performance improvements in EV batteries is accelerating, and Sepion has demonstrated a clear path from customer qualification to revenue," said Shyam Kamadolli, managing director at Fine Structure Ventures. His firm previously led Sepion's $16 million Series A back in November 2021, giving him a front-row seat to the company's progress—and stumbles—since.
Strategic Capital Arrives
The participation of W.L. Gore and Syensqo Ventures marks something of a coming-out moment for Sepion. Both are global materials science players with vast manufacturing footprints and technical expertise that could prove invaluable as the startup scales.
Edward Rubin, who oversees W.L. Gore's venture investments, pointed to Sepion's manufacturing readiness and cost structure as deciding factors. Coppelia Marincovic, partner at Syensqo Ventures, highlighted what she sees as platform potential—the possibility that today's separator coating becomes tomorrow's broader materials technology.
Whether that optimism proves warranted depends largely on execution over the next 18 months.
Founded in 2015 as a spinout from Lawrence Berkeley National Laboratory's Molecular Foundry, Sepion has layered government support atop its private funding. The company has secured over $9 million from ARPA-E and the California Energy Commission—grants that subsidized early R&D but come with strings and milestones.
In September 2023, Sepion opened a 25,000-square-foot coating and pilot facility in Alameda. A year later, it announced plans for a significantly larger manufacturing site in West Sacramento, targeting production by 2027. That timeline assumes funding continues, customer orders materialize, and the dozens of variables that sink hardware companies stay cooperative.
For now, Sepion has capital, strategic partners, and technology that at least some battery manufacturers think worth testing. What it doesn't yet have is proof the market will pay at scale for thinner coatings and lighter batteries.
That's the $10 million question.
