Staff Cell Product Development Engineer

Factorial Energy is an American solid-state battery company headquartered in Billerica, Massachusetts, focused on developing high-performance energy storage solutions for electric mobility, defense, and AI-driven robotics applications. The company designs and manufactures solid-state batteries that overcome the fundamental limitations of conventional lithium-ion technology, including energy density constraints, weight penalties, and safety concerns associated with liquid electrolytes. Factorial's batteries have demonstrated real-world capability, including powering a vehicle on a drive exceeding 1,200 kilometers on a single charge using solid-state cells. Factorial's mission centers on advancing American technology leadership, economic resilience, and domestic industrialization of next-generation battery technology. The company positions its work as critical to U.S. national security, energy independence, and global competitiveness across the automotive, defense, and robotics sectors. With over 10 years of research and development and more than 150 patents and patent applications, Factorial has built a deep intellectual property portfolio and established partnerships with four top-tier automotive manufacturers, including Stellantis. What distinguishes Factorial is its capital-efficient manufacturing approach: its technology is approximately 80 percent drop-in compatible with existing lithium-ion production infrastructure, significantly reducing the cost and disruption required for partners to transition to solid-state production. The company also employs a proprietary dry-coating process to further enhance manufacturing efficiency and reduce costs. Recent milestones include securing its first commercial aerospace battery order and completing successful flight tests with partner Tulip.

Who We Are

 

Factorial Energy is a pioneering U.S.-based solid-state battery company driving the future of energy storage and electrification. Partnered with global leaders including Mercedes-Benz, Stellantis, Hyundai, and Kia, Factorial is at the forefront of developing next-generation e-mobility platforms for commercial, defense, and consumer applications—spanning electric vehicles (EVs), drones, eVTOL aircraft, power tools, marine systems, robotics, and more. The company has achieved multiple industry firsts, including being the first to power a demonstration vehicle with a global OEM (Mercedes- Benz) which achieved over 1,200 km (749 mi) of range, and the first to earn UN 38.3 certification for automotive-sized lithium-metal solid-state cells, the first to deliver B-samples of automotive-sized solid-state batteries to major OEMs.

 

The Opportunity:

 

Factorial Energy is seeking a Staff Product Development Engineer to join our team in our Cheonan, South Korea, location. This person will be responsible for leading the design and development of EV pouch and prismatic cells from concept through mass production, driving key technical decisions, and ensuring product competitiveness in performance, safety, and manufacturability. The ideal candidate will bring 8+ years of cell product development experience and a proven track record of taking products to mass production.

 

In this role, you will:

 

• Lead product design and technology roadmap development.
• Develop and optimize cell design, including DOEs, production, validation, certification, use cases, DVP, and report templates.
• Coordinate with customers on testing standards, plans, and schedules.
• Serve as technical lead for projects — translate customer requirements into solutions, lead design reviews and risk assessments, and mentor engineers.
• Transfer R&D designs into scalable manufacturing, define process windows and control plans, and resolve critical manufacturing issues.
• Lead mass production readiness assessments and execute Design Verification (DV) evaluations in accordance with product development milestones.
• Evaluate key materials and drive adoption of advanced technologies.
• Follow up on cell testing — conduct tests, analyze results, resolve testing issues, and support the cell development team in failure analysis.
• Track and interpret international standards and regulations, and benchmark against industry-leading testing standards.

 

We are looking for people who:

 

• Master's degree in a relevant field and at least 8 years of cell development experience, with a proven record of more than one mass-produced product.
• Familiarity with cell design and production, testing standards, and safety regulations.
• Experience with pouch and prismatic cells (electrode design and mechanical optimization); deep understanding of full process flow and ability to define key process windows.
• Proficient in electrochemical and safety testing.
• Strong understanding of Li-ion cell working principles, degradation mechanisms, and influencing factors.
• Strong failure analysis, problem-solving, and data analysis capabilities, with meticulous attention to data and a strong safety mindset.
• Able to quickly understand customer requirements and convert them into design and validation plans.
• Strong teamwork and cross-departmental communication skills.
• Fluent in English (written and spoken) — required for daily communication.
• Strong sense of responsibility and dedication; thorough in work with the ability to thrive in a fast-paced technology or manufacturing environment.
• Preferred: prior work experience at a battery company.
• Preferred: experience developing customer projects and successfully achieving mass production.