Sionic Energy and Group14 Set New Elevated-Temperature Benchmark for Silicon-Carbon Anodes in High-Energy Lithium-Ion Cells

ROCHESTER, N.Y., Dec. 8, 2025 /PRNewswire-PRWeb/ — Sionic Energy (“Sionic”) today announced new joint results with Group14 Technologies (“Group14”) showing industry-leading elevated-temperature stability for 100% silicon-carbon anodes in high-energy lithium-ion cells. By combining Group14’s SCC55® silicon-carbon anode material with Sionic’s proprietary Rapid Integration Silicon Platform™ containing 100% silicon-carbon (Si-C) anode and enhanced electrolyte, the companies have set a new benchmark for silicon battery technology, expanding its path to a broader set of applications in transportation, consumer electronics, and aviation markets.

Elevated-Temperature Stability at 45°C Cycling and 60°C Storage

The companies tested Sionic’s Rapid Integration Silicon Platform with SCC55 in 4-Ah, 10-Ah, and 20-Ah pouch cells under electrolyte-lean conditions with NMC 83 cathodes. Cells delivered stable 1C/-1C cycling at 45°C, and retained >70% of room-temperature cycle life. Storage testing at 45°C and 60°C displayed substantial suppressed gas generation and lower impedance growth, supporting the potential of extended calendar life over baseline chemistries

A Practical Path for 100% Silicon-Carbon Anodes

Sionic’s graphite-free Rapid Integration Silicon Platform produces market-leading performance in energy density with Group14’s SCC55, delivering up to 400Wh/kg, and complemented with exceptional cycle life (up to 1200+) and high-rate performance, in cell formats partners already run.

“I’ve spent years watching the industry chase silicon’s promise and hit the walls of complexity, cost, development time, and narrow performance. That’s why I’m proud to share this Sionic benchmark and the Group14 partnership that breaks through those walls and accelerates silicon’s broad market adoption,” said Ed Williams President and CEO of Sionic Energy. “Our Rapid Integration Silicon Platform delivers up to a 50% jump in performance while dropping right into industry standard equipment with no complexity: no pre-lithiation, no external compression, no extensive cell design efforts, and industry standard cell formats.”

SCC55 at Scale

SCC55 uses a porous hard-carbon scaffold to manage expansion and side reactions, preserving silicon integrity over long life. The material is already proven at commercial volumes with cycle-life data in the 1500–3000-cycle range.

“This benchmark is a powerful validation that silicon batteries are market-ready,” said Rick Luebbe, CEO and Co-Founder of Group14 Technologies. “Customers want true drop-in silicon-carbon anodes that deliver up to 50% higher energy density, dramatically faster charging, and robust lifetime across extreme temperatures. These latest results with 100% SCC55 show that with world-class materials and strong cell engineering, we can meet those expectations at scale, today.”

Applications and Next Steps

The results show a viable silicon-dominant path for EVs, aerospace and eVTOL platforms, and compact electronics that need long life and elevated-temperature resilience.

A technical white paper with full test data is available to qualified OEMs, cell manufacturers, and investors at: https://group14.technology/resources/whitepapers/sionic-energy-and-group14-whitepaper/.

Sionic and Group14 are now engaging with commercial partners to translate these results into production programs and with investors focused on silicon-dominant systems as a lever for performance and value creation.