Mechanical & Design Engineer II – III

Oxylus Energy; Branford (CT); On-site; USD 90,000 - 110,000; Full time

Benefits offered by this job

Competitive salary

Medical, dental, and vision coverage

Paid sick days and vacation

401k match

Diverse and inclusive work environment

Job summary

Oxylus Energy is seeking a Mechanical & Design Engineer II–III to own the mechanical design of the CO₂ electrolyzer from cells to stacks. You will translate electrochemical requirements into robust, manufacturable hardware, covering flow fields, seals, manifolds, and balance-of-stack components.

This hands-on role involves building and testing hardware, working with R&D and engineering teams to diagnose issues and improve performance, durability, and scalability.

Qualifications

• Bachelor's degree in Mechanical Engineering or related field.
• Engineer II: 2–4 years experience; Engineer III: 4+ years or PhD with limited experience.
• Proficient in 3D CAD and GD&T for manufacturing drawings.
• Hands-on experience with CFD tools (e.g., ANSYS Fluent or COMSOL).
• Familiarity with electrochemical hardware development (electrolyzers, fuel cells, batteries).
• Experience building and testing mechanical prototypes.
• Understanding of sealing, compression, and fluid-containing vessels.

Responsibilities

• Own the mechanical design of CO₂ electrolyzer cells and stacks.
• Design and specify all mechanical balance-of-stack components.
• Use CFD to model gas/liquid flow, pressure drop, and heat transfer.
• Produce CAD models and manufacturing drawings with GD&T.
• Select materials for chemical compatibility and performance.
• Design and build prototype cells and stacks; run leak and pressure tests.
• Diagnose hardware failures and implement design fixes.
• Collaborate with machine shops and suppliers for fabrication and qality.

Skills

3D CAD proficiency

CFD experience

Hands-on prototyping

Detail-oriented

Communication skills

Problem solving

Sealing/pressure vessels

Education

B.S. in Mechanical Engineering or related field

Tools

SolidWorks/Creo/NX

ANSYS Fluent/COMSOL

Job description

Mechanical & Design Engineer II – III

On-site, Branford, CT (must be willing to relocate to the Bridgeport/Stamford area within one year of the start date)

About Oxylus Energy

Oxylus Energy is a climate-tech company building solutions that can scale. Our breakthrough electrochemical technology converts carbon dioxide into low‑carbon fuels and chemicals, reducing the world's dependence on fossil fuels. We are a team of scientists, engineers, and problem solvers working to make that future real.

Job brief

As Mechanical & Design Engineer, you will own the mechanical design of Oxylus’ CO₂ electrolyzer, from single cells to multi‑cell stacks, along with all mechanical aspects of the balance of stack. You will turn electrochemical requirements into robust, manufacturable hardware. That covers flow fields, bipolar plates, end plates, manifolds, seals, compression systems, current collectors, and the fluid connections that integrate the stack into a test or production system.

This is a hands‑on role. Beyond modeling and drawings, you will build and test the hardware you design, working side by side with our R&D and engineering teams to diagnose problems and improve performance, durability, and scalability.

What You Will Do

• Own the mechanical design of our CO₂ electrolyzer cells and stacks, including flow fields, bipolar plates, end plates, manifolds, gaskets and seals, and compression hardware.

• Design and specify all mechanical balance‑of‑stack components, including fluid connections, current collectors, insulation, and mounting and integration hardware.

• Use computational fluid dynamics (CFD) to model gas and liquid flow, pressure drop, and heat transfer, and use the results to optimize designs.

• Produce detailed CAD models and manufacturing drawings with appropriate tolerancing (GD&T), and manage design revisions and documentation.

• Select materials for chemical compatibility, corrosion resistance, and electrical and thermal performance in an electrochemical environment.

• Design and build prototype cells and stacks, run leak and pressure checks, and support electrochemical testing on our test stations.

• Diagnose hardware‑related failures such as leaks, uneven compression, flow maldistribution, and corrosion, and implement design fixes.

• Work with machine shops and suppliers on fabrication, quotes, and quality, and design for manufacturability as we scale to larger formats.

• Contribute to safety reviews of hardware that handles pressurized and hazardous gases, including CO.

• Occasionally perform hands‑on manufacturing processes, including operating of CNC machine or band saws.

Who You Are

• A degree in Mechanical Engineering or a related field, with experience matching the level:

  • Engineer II: B.S. with 2–4 years, or M.S. with 1–2 years of relevant experience.

  • Engineer III: B.S. with 4+ years, M.S. with 2–4 years, or Ph.D. with 0–2 years of relevant experience

• Proficiency in 3D CAD, such as SolidWorks, Creo, or NX, and in producing manufacturing drawings with GD&T.

• Hands‑on experience with CFD tools such as ANSYS Fluent or COMSOL.

• Familiarity with electrochemical hardware development, such as electrolyzers, fuel cells, or batteries.

• Hands‑on experience building and testing mechanical prototypes.

• Understanding of sealing, compression, and fluid‑containing vessels.

• Attentive to detail, with strong problem‑solving and organizational skills.

• Good written, verbal, and presentation skills.

Nice to Have

• Direct experience designing electrolyzer or fuel cell stacks.

• Experience with structural or thermal finite element analysis (FEA).

• Familiarity with pressure equipment codes and standards, such as ASME.

• Experience with machining, 3D printing, or other rapid‑prototyping methods.

• Experience with CAM software.

• Experience scaling hardware from lab prototypes to pilot or production designs.

Salary

• Engineer II: USD 90,000–100,000 per year base salary commensurate with experience, education, and skills.

• Engineer III: USD 100,000–110,000 per year base salary commensurate with experience, education, and skills.

Benefits

• Competitive salary

• Medical, dental, and vision coverage

• Paid sick days and vacation

• 401k match

• A diverse and inclusive work environment

If you need an accommodation during the application process, reach out to [e-mail].

Equal opportunity

We believe the distinct contributions of each person fuel our success. To keep our products and culture inclusive of all viewpoints and experiences, Oxylus Energy does not discriminate on the basis of race, color, religion, sex, national origin, gender identity or expression, sexual orientation, age, marital status, veteran status, disability, or any other characteristic protected by law.