Company

Joe Mastrangelo is driven by a vision of energy abundance as the foundation of human progress.

Joe joined Eos Energy Enterprises as Chief Executive Officer in 2019, bringing three decades of leadership across the global energy sector. His career spans technology innovation, industrial manufacturing at scale, and worldwide commercial deployment—providing the rare, end-to-end perspective required to steer energy systems from laboratory breakthroughs into real-world impact.

Throughout his career, Joe has worked to build cultures that nurture the unconventional thinkers and committed doers needed to tackle problems others consider impossible. Whether integrating complex organizations or building teams from the ground up, Joe recognizes that people are the key to success and strives to create environments where bold ideas are matched by disciplined execution.

Before joining Eos, Joe served as CEO of GE’s Power Conversion business and as President and CEO of Gas Power Systems for GE Power, leading global operations of more than 15,000 employees across 60+ countries. These roles reinforced a conviction central to his vision: revitalizing America’s ability to design and manufacture physical, industrial-scale technologies is critical—not only to economic competitiveness, but to addressing the world’s greatest challenges.

At Eos, Joe is translating that conviction into action. The company is rebuilding U.S. manufacturing capacity to produce breakthrough zinc-based, high-density battery energy storage at gigawatt scale—creating American jobs while delivering technology the world urgently needs.

Michelle Buczkowski is driven by a belief—and a career spent proving—that people power the world.

Michelle joined Eos Energy Enterprises in 2024, bringing nearly 20 years of experience in talent acquisition and development, workforce transformation, and organizational culture and communications in highly-regulated, operationally-complex industries. She is sought out for building teams with the resilience to take on rapid growth and dynamic change and deliver with excellence—in ways that benefit not just the companies Michelle works for, but every individual within them.

Throughout her career in and around Pittsburgh, one of the United States’ historic centers of industrial leadership, Michelle has led the alignment of people strategies with organizational goals, unlocking employee potential to drive corporate impact. Michelle shepherded CONSOL Energy’s employee base through the Marcellus Shale natural gas boom, architected a multi-year roadmap that brought the PNC Bank’s vision of a “Talent-Focused Culture” to life, and, most recently, as Managing Director of Human Resources at Duquesne Light, partnered closely with union leadership and executive teams to transform compensation strategies and labor relations.

At Eos, as the company’s first Chief Administration Officer, Michelle is delivering on her reputation as passionate and ambitious but clear-thinking and pragmatic leader of people. Reshaping how the company leads, engages, and evolves its workforce to unleash the ingenuity and determination of every Eos employee, Michelle is creating the organizational capacity—from the R&D lab to the factory floor—to meet the moment and the mission to build the energy storage the world urgently needs.

Bringing over 25 years of finance, customer, and energy industry experience to the organization, Nathan Kroeker transitioned to CCO of Eos in March of 2025, after serving as CFO from January of 2023. In his time as CFO, Nathan secured over $850 million in transformative financing, positioning Eos for significant operational expansion. Having held financial leadership roles with several energy firms during his career, Nathan has a keen awareness of how the energy sector has evolved over the last decade, and he understands the challenges that lie ahead. Prior to joining Eos, Nathan served as Chief Financial Officer of Spark Energy before taking over as Chief Executive Officer in 2014 when he led the company’s IPO—the first independent retail energy company to successfully IPO on the NASDAQ. His prior experience as CEO gives him a unique understanding of both the complexities of the industry and the evolving needs of customers, while his time as CFO offered a distinct perspective of the financial and commercial landscapes of the industry, allowing him, in his new role as CCO, to create customer-centric solutions that are not only impactful, but also financially sustainable.

Nathan earned his undergraduate degree in Accounting from the University of Manitoba where he graduated with distinction. He believes in the fundamental role of energy storage in the global energy transition, and his business acumen is a key asset in maintaining Eos’ leadership momentum as we shift into a new era of electrification.

Alessandro brings over 25 years of finance leadership experience across financial planning, commercial finance, corporate audits, business transformation, and operations in the industrial sector. He has led multi-billion-dollar regional and global finance teams, having held multiple divisional CFO roles between GE, Baker Hughes and Johnson Controls.

Most recently Alessandro led the FP&A and Vector of Growth Finance team for Johnson Controls, overseeing planning, commercial, service, and system finance, helping to drive stronger performance, cash generation, operational accountability, and enterprise transformation. Prior to this role, Alessandro was the CFO for EMEA and then APAC for Johnson Controls. Prior to that, he served as Global CFO for the Oil Field Equipment, Latin America and the Flexible Pipes business at Baker Hughes.

Alessandro brings the financial leadership, operational rigor, and global experience necessary as Eos scales operations, advances manufacturing execution, and supports growing customer deployments.

As Chief Operating Officer, John will lead the company’s operations, supply chain, and manufacturing strategy. John has more than three decades of experience in global manufacturing, operations, supply chain and business development from his tenure at Jabil Inc., a multibillion-dollar global manufacturing solutions provider. Most recently, John served as Senior Vice President of Operations for Europe and the Americas, generating more than $14 billion in annual revenue and overseeing over 70,000 employees across 30+ factories worldwide.

Recognized for his transformative leadership, John has led multiple manufacturing facilities to win the prestigious Shingo Prize for Operational Excellence. His strategic planning, disciplined execution, and ability to scale complex operations have consistently driven meaningful growth and operational efficiency.

After starting as a Senior Battery Scientist at Eos in 2015, Francis Richey held positions as product development manager and was named Vice President of R&D in December 2020. His vast knowledge of electrochemical engineering and passion for scaling technology from the lab to a commercial product has been integral for advancing and refining Eos Znyth™ battery technology and keeping the organization at the forefront of developing battery storage alternatives to lithium-ion. After graduating with a Bachelor of Science in Chemical Engineering from Penn State University and a Ph.D. degree from Drexel University with a focus on Chemical and Electrochemical Engineering, Francis began his career as a Postdoctoral Research Scientist at Stanford University leading a collaborative research effort between UC Berkeley and Stanford to investigate corrosion mechanisms in aqueous Metal air batteries. He holds 9 patents, has publications in the Journal of the Electrochemical Society and Journal of American Chemical Society, and has presented at numerous electrochemical conferences on fuel cells, batteries, and capacitors. By advancing zinc-based battery technology and leading R&D efforts at Eos, Francis is a driving force for helping Eos change the way the world stores power.

Marie Batz Martin is an accomplished legal and business executive with more than 20 years of experience advising global organizations through growth, strategic transactions, operational transformation, governance, compliance, and enterprise risk. She has served as General Counsel, Chief Compliance Officer, Corporate Secretary, and trusted advisor to CEOs and Boards across the industrial, aerospace, technology, and energy sectors. Most recently, Marie served as Chief Compliance Officer at Coherent Corp., where she led the company’s global ethics and compliance, privacy, international trade compliance, and AI governance programs and supported business integration across the multibillion-dollar enterprise. From 2020 to 2022, Marie served on the executive leadership team of FlightSafety International, a Berkshire Hathaway company and global leader in aviation training and flight simulation technology. As Executive Vice President, General Counsel, Corporate Secretary, and Chief Ethics and Compliance Officer, she led the company’s global legal and compliance organization and advised the business on strategic acquisitions and divestitures, governance, regulatory matters, and operational initiatives. Earlier in her career, Marie spent more than a decade at Alcoa and Arconic, where she held senior legal and business roles supporting complex global operations, strategic transactions, mergers and acquisitions, joint ventures, and large-scale manufacturing initiatives. She also practiced law at Dentons and began her career as a financial analyst at Goldman Sachs.

Marie earned her Juris Doctor from Duquesne University School of Law, a Master of International Affairs in International Finance from Columbia University, and a Bachelor of Arts in Economics and Spanish from the University of Notre Dame. She has also completed executive education at Harvard Business School and serves on nonprofit and professional boards.  At Eos, Marie brings the legal judgment, global business experience, and disciplined approach to governance and risk needed to support the Company as it scales its operations, advances its strategic priorities, and responds to growing demand for long-duration energy storage.