HR Intern

About LeydenJar

At LeydenJar Technologies, we’re on a mission to redefine the future of energy storage. Our goal is to become the world’s innovation leader in advanced battery anodes, empowering the next generation of batteries that drive progress.

Why does this matter? Because the world needs higher energy density batteries not just for better consumer electronics, but for electric vehicles, e-flight, and beyond. While the battery industry typically advances by only 3% per year, our breakthrough pure silicon anode technology delivers an improvement of up to 70%, a true game changer. Often called the “holy grail” of the battery industry, our technology unlocks new possibilities for electrification, sustainability, and resilience in global supply chains.

What we do:

• We produce pure silicon anode rolls that fit seamlessly into existing battery cell manufacturing lines, enabling customers to make a quantum leap in performance or create entirely new product categories.

• Our initial focus is on consumer electronics, with automotive applications already in development.

• By leveraging semiconductor thin-film technology (plasma deposition) and scaling it to battery anodes, we’ve overcome the long-standing challenges of silicon in batteries, delivering durability and efficiency at scale.

To meet global demand, we’re scaling up:

• PlantOne in Eindhoven opens in 2026-2027, producing anode rolls and validating our roll-to-roll production tools.

• PlantTwo, our large-scale production facility, will follow, establishing LeydenJar as a key player in the global battery market.

This is an enormous opportunity and an ambitious journey. It requires bold, creative, and diverse minds who share our passion for innovation and sustainability. At LeydenJar, we value different perspectives, inclusive collaboration, and gender equality because we know that diversity fuels breakthrough ideas.

Time to put your books aside and turn theory into practice!

We are looking for a motivated HR Intern to join our growing team. In this role, you will work closely with the HR Manager and HR Officer, gaining hands-on experience in a fast-paced start-up environment where no two days are the same.

You will be exposed to the full employee lifecycle and develop practical HR skills while contributing to meaningful people initiatives at LeydenJar.

Your responsibilities will include:

• Assisting with daily HR operations and employee administration

• Acting as a point of contact during recruitment and selection processes

• Supporting hiring managers and Heads of Department throughout recruitment

• Reviewing and managing our Applicant Tracking System

• Drafting standard individual employment contracts or Internal/ External letters,

• Coordinating and supporting new hire onboarding and, when required, relocation

• Managing employee offboarding.

• Promoting and supporting LeydenJar’s fun, well-being, and wellness initiatives

This internship offers a unique opportunity to gain broad HR exposure, take ownership of responsibilities, and make a real impact within a dynamic start-up culture.

About you:

• You are currently enrolled in a college or university degree-seeking program (this is mandatory for the internship)

• You are eager to learn, proactive, and comfortable taking ownership of your responsibilities

• You have excellent English communication skills, both written and verbal; Dutch is a plus

• You are a strong team player who thrives in a multidisciplinary, multicultural, and fast-paced environment

• You are organized, detail-oriented, and able to manage multiple tasks simultaneously

• You are eligible to complete your internship in the Netherlands

Why LeydenJar?

• Unleash Your Potential: Step into a workplace where growth and ownership go hand in hand. We empower every individual regardless of background, gender, or identity to thrive and achieve their career aspirations.

• Continuous Learning: Access our online learning platform (Udemy) to develop your skills and unlock new opportunities for personal and professional growth.

• Diverse, Inclusive & Equal: Be part of an international team of 20+ nationalities, where everyone’s voice matters, and where diversity, equity, and inclusion are more than values they’re actions.

• Community & Connection: From team-building events and monthly lunches to year-end celebrations and inclusive gatherings, we create spaces where everyone feels welcome and engaged.

Are you ready to take on the challenge as a HR Intern? We are looking forward to your application!

If you'd like to learn more about LeydenJar's amazing team, see below:

At LeydenJar we value diversity, and we provide equal opportunities to all applicants without regard to race, color, ethnicity, religion, gender, pregnancy/childbirth, age, national origin, sexual orientation, disability, etc. If there are two or more applicants of equal suitability for a certain position, LeydenJar can under circumstances decide to select applicants based on positive discrimination in full compliance with all relevant and applicable law.