Penn State DuBois and Metaltech Inc., a leading powdered metal manufacturer, have commenced a new research initiative aimed at developing next-generation energy storage solutions, supported by a $70,000 grant from the 2025 Manufacturing PA Innovation Program. Launched in June, this collaborative effort focuses on creating sponge iron electrodes for iron-air batteries by repurposing mill scale, a significant byproduct of steelmaking, signaling a strategic move towards more sustainable and cost-effective grid-scale energy storage. The project leverages local expertise and resources to address both environmental challenges and the growing demand for advanced battery technologies.

Iron-air batteries are gaining traction as a promising alternative for large-scale energy storage due to their inherent cost-effectiveness and environmental advantages. These batteries utilize an iron negative electrode paired with an air-based positive electrode within an alkaline electrolyte. Their operational mechanism involves a reversible reaction between iron and oxygen during charging and discharging, which enables high energy delivery while mitigating common issues such as dendrite formation that plague other battery chemistries, which can lead to short circuits or premature failure.

The core of the research involves transforming mill scale—a steelmaking waste product typically containing approximately 70% iron along with various oxides and contaminants—into high-purity sponge iron. Traditionally, steel producers incur costs for disposing of this material. The project employs a direct reduction process, which removes oxygen from iron oxides at elevated temperatures to yield a porous, honeycombed microstructure ideal for battery electrodes. “Recycling mill scale into sponge iron for battery electrodes not only addresses an environmental challenge but also adds value to a waste product,” stated Ramakrishnan “Ram” Rajagopalan, professor of engineering at Penn State DuBois and lead researcher on the campus side. He emphasized that the project also provides invaluable hands-on experience for students in advanced manufacturing and energy storage.

Metaltech Inc. contributes its expertise in hydrogen-based reduction processes for producing sponge iron, a method recognized for its lower energy consumption and superior product quality, utilizing cleaner fuel sources. The resulting sponge iron powder will undergo rigorous characterization using advanced analytical techniques, including scanning electron microscopy, X-ray diffraction, and particle size analysis, to ensure optimal consistency and performance. The research team will further enhance electrode performance by incorporating additives designed to suppress electrode passivation and hydrogen evolution during battery cycling, thereby improving overall efficiency and lifespan.

Early laboratory tests utilizing cyclic voltammetry, a technique for examining electron transfer during chemical reactions, have demonstrated promising redox activity for the mill scale-derived sponge iron. “It’s exciting to see potential for real-world application in energy storage,” Rajagopalan noted. Tony Zaffuto, founder and president of Metaltech Inc., highlighted the strategic advantage of the partnership, stating, “Having access to experienced faculty and students right here in our region is a huge advantage.” This project marks the fourth time Penn State DuBois has secured funding through the Manufacturing PA Innovation Program, underscoring its consistent contribution to regional industrial innovation. Jungwoo Ryoo, chancellor and chief academic officer at Penn State DuBois, commended the initiative, noting its direct benefit to the local powder metal industry and its role in empowering it with necessary innovations.