Hydrometallurgy Intern (Process Development & R&D) | Climate Tech Startup

Tozero is a materials and green technology company focused on lithium-ion battery recycling, with a mission to close the loop on battery materials and support the transition to a circular economy in the electric vehicle and energy storage sectors. The company develops and operates processes to recover critical raw materials from spent batteries, reducing dependence on virgin mining and lowering the environmental footprint of battery supply chains. Their work addresses one of the most pressing challenges in the clean energy transition: what to do with batteries at end of life. Tozero positions itself as a done-for-you infrastructure provider for heavy-duty fleet operators, offering uptime and battery lifecycle services that help fleets manage battery health, longevity, and end-of-life processing. By integrating battery management with recycling infrastructure, the company enables fleet operators to maximize the value of their battery assets while ensuring responsible disposal and material recovery. What makes Tozero distinctive is its vertically integrated approach, combining operational fleet support with downstream recycling capabilities. This dual focus allows the company to serve both the immediate needs of fleet electrification and the longer-term material recovery goals of a sustainable battery economy, making it a unique player at the intersection of fleet services and green materials technology.

ABOUT US

tozero is Europe's leading deep-tech startup specializing in the recycling of lithium-ion batteries. Committed to accelerating decarbonization  and transforming the material life-cycle, we’re actively crafting sustainable recycling solutions for a cleaner and more innovative future.

WHAT WE'RE LOOKING FOR

As a Hydrometallurgy Intern, you will support process development and R&D efforts in leaching, kinetics, and mass transfer for the recovery of critical battery materials. You will work closely with experienced engineers to analyze reaction mechanisms, optimize scaling parameters, and assess process efficiencies through experimentation and simulation.

WHAT YOU CAN EXPECT

What You’ll Do

• Assist in designing and conducting hydrometallurgical leaching and separation experiments, with a focus on kinetics and diffusion mechanisms.
• Perform data analysis (e.g., kinetic modeling, reaction rate determination, diffusion studies) to support process optimization.
• Contribute to scaling studies and process integration, linking laboratory results to pilot-scale implementation.
• Support in evaluating mass transfer, reaction mechanisms, and process control factors.
• Document findings and contribute to technical reports and presentations
• Utilize simulation software for process simulation and thermodynamic modeling. Apply Minitab or similar statistical tools for design of experiments (DOE), regression analysis, and process optimization.

Your profile

What You Bring to the Table

• Currently pursuing or completed a Master’s degree in Chemical Engineering, Metallurgical Engineering, Materials Science, or a related field.
• Strong understanding of reaction kinetics, diffusion principles, and hydrometallurgical processes.
• Proficiency in data analysis tools (Excel, Python, OriginLab, or MATLAB) for kinetic and statistical analysis.
• Hands-on laboratory experience in chemical or metallurgical processing is desirable.
• Familiarity with Minitab or other statistical software for experimental design and process optimization.
• Self-motivated, proactive, and capable of working independently as well as in a team.
• Strong problem-solving skills with a structured, analytical mindset.
• Fluent in English (both written and spoken).
• Nice to have: Experience in chemical process modeling and simulation (HSC Chemistry, ASPEN, or equivalent).

Why us?

At tozero, we believe in providing a supportive and enriching work environment to help our team achieve top performance 

• Free Snacks and Drinks in the Office: Stay energized throughout the day with a variety of snacks and beverages.
• Jobticket: Conveniently commute to work and all around Germany with our fully subsidized Deutschlandticket.
• Dynamic Startup Environment: Thrive in a highly dynamic startup culture, collaborating with experts in the field and contributing to innovative projects that shape the future.