The challenge

Lithium-sulfur batteries promise up to five times the energy per weight of today's lithium-ion cells, but the polysulfide shuttle effect (and many other technical issues) has kept them out of commercial production. Until now. Pentalys Energy has developed precisely nanoengineered materials for separator and cathode that suppress this shuttle mechanism for thousands of cycles at 1C, enable rates up to 8C, and ensure safe operation. All based on abundant sulfur materials for cost-efficient and sustainable solutions.

The materials work. Now we need to deliver them to the first customers, understand them deeper, and improve the first products. That is where you come in: as R&D Engineer, you will spend many of your days in the lab, synthesizing our cathode and separator materials and building the coin and pouch cells that show what our materials can do.

What you'll do

• Synthesize and refine our proprietary cathode and separator materials; running the chemistry hands-on, improving procedures, documenting and analysing results and procedures.
• Build cells at both scales: coin cells for fast screening of materials and formulations, pouch cells for demonstrating real-world performance.
• Test and characterize what you make, and connect the dots between synthesis parameters, material properties, and cell behaviour.
• Work closely with the rest of the team, especially materials development lead, to decide what to try next. In an early-stage company, your results and input guide the direction.
• Help keep a small lab running well: shared responsibility for equipment, chemicals, and safe working practices.

What matters to us

• Mindset above all. You want to make a difference by joining a startup, and you act like it: you take ownership, ask why, solve problems, and don't wait to be handed a protocol. Early-stage means incomplete data, evolving specs, and wearing multiple hats. This excites you, since that means you can find new solutions.
• Solid hands-on skills in chemical synthesis, cell building, or ideally both.
• At least two years of experience in battery R&D. Relevant PhD positions are counted as experience.
• Careful, well-documented lab work.

Nice to have, not required

• Master's degree in chemistry, materials science, electrochemistry, or a related field. But what you do in the lab matters more. Strong candidates with a technician background and hands-on battery experience are encouraged to apply.
• Experience with lithium-sulfur chemistry, sulfur cathodes, membrane or separator technology.
• Glovebox or dry-room cell assembly experience, and pouch cell building in particular.
• Electrochemical testing: cycling protocols, EIS, data handling.

What we offer

• Real ownership: genuine influence on both the technology and the direction of the company from an early stage.
• A small, but dedicated team that have deep technical expertise and will work together with you to find solutions.
• A front-row seat to pioneering next-generation battery materials that redefine energy storage and make impossible electrification possible.

Send your CV and a brief cover letter outlining your relevant track record and motivation to career@pentalys-energy.com before August 15, 2026.

Pentalys Energy is building an inclusive workplace. We encourage applicants of all backgrounds and make hiring decisions based on skills and proven track record.