Solvay Ventures, the venture capital fund of Solvay, invested in Sepion, a California-based start-up that specializes in advanced membranes for batteries with Li-metal anodes and liquid electrolytes. The $16-million funding round was led by Fine Structure Ventures, and also includes other climate tech investors.
Sepion raised funds to accelerate commercialization of lithium metal batteries for long-range and low-cost electric vehicles.
Li-metal batteries enable high energy density and are strongly sought-after solutions for the electric vehicles market. However, the growth of dendrites can cause the batteries to fail and prevents them from having long life cycles. Sepion’s technology, which is based on an innovative polymeric membrane, prevents the growth of dendrites.
Sepion’s technology can be readily adopted as it leverages the current Li-ion manufacturing infrastructure and liquid electrolytes. As a leader in Li-ion electrolyte additives, Solvay provides a complementary expertise to Sepion’s core technology.
This is exactly the mission of our battery platform and by investing in Sepion’s technology, we are progressing in our journey to enable safer, more performing and more sustainable batteries.—Mike Finelli, President of Growth Initiatives at Solvay
With the support of the ARPA-E IONICS (earlier post) and CalSEED programs, Sepion has developed a nano-porous polymer membrane that improves the performance of lithium metal anodes, promising a 40% increase in EV range, a 20% reduction in cost, and improved safety.
Sepion’s current product, a lithium-electrode sub-assembly (LESA) consisting of the membrane and lithium metal anode, is designed to integrate with existing lithium-ion manufacturing infrastructure lowering the barrier to market adoption.
This integration is accomplished with a hybrid lithium metal cell design in which a solid lithium metal anode, protected by Sepion’s membrane, is paired with a traditional metal oxide cathode and liquid electrolyte. This would enable an existing Gigafactory to become a 1.4-fold Gigafactory simply by switching to Sepion’s LESA component and cell design.
In March, the California Energy Commission awarded Sepion a $1.4-million grant to advance the development of its safe anode-free hybrid lithium-metal cells from a lab-scale validation to a pre-prototype. This project, which runs through March 2024, will enhance two key components—the electrolyte and current collector, that heavily influence the safety, cycle life, fast-charge capabilities, and cost of finished lithium-metal batteries.
Synergies between Sepion’s membrane and the optimized electrolyte will further differentiate hybrid lithium-metal cells coming out of this program and elevate the full cell design from technology readiness level (TRL) 4 to TRL 6.
Sepion will produce and validate prototype lithium-metal cells with leading automotive manufacturers.