Yessica Klein
8 min read
09 November 2025
Antoine Welter returned to Luxembourg only after years spent studying and working across the US, China, Spain and Germany. In 2021, however, he swapped a decade of business analytics and consulting to launch Circu Li-ion alongside Dr. Xavier Kohll, the cofounder he met over beer while still in high school in Spain. And it was also over drinks that the two came up with their business idea. “We looked at a few things that could make sense, and we ended up doing batteries because we follow easy principles,” he says. Circu Li-ion confronts one of the most overlooked inefficiencies in the green transition: how batteries are taken apart, diagnosed and reused.
Circu Li-ion’s machine-as-a-service model aims to give used batteries a second life by automating disassembly and analysis at scale. “Too much waste is thrown into the recycling process that doesn’t belong there,” Antoine says. “If we don’t automate it, we’ll never have the necessary impact.” The company now operates in Luxembourg and Germany, serving clients in the EV, power tools and energy storage sectors. In 2023, it won backing from the European Innovation Council Accelerator and continues to attract public and private investment.
How did your path from business intelligence and consulting lead to deeptech and battery upcycling?
Consulting gave me the structure and tools to manage complexity, but I always knew I wanted to work on something that really moved the needle. My mother inspired me early on to care for the planet, and for a long time I wasn’t sure how to combine that with my passion for business. Eventually I realized there was a way to do both, and I wanted to contribute meaningfully, not just watch others do it.
What do you see as the biggest misunderstanding around battery recycling today?
Many people think dropping something in a recycling bin means the job is done, but that’s far from the truth. Modern packaging and battery assemblies are incredibly complex. There are multiple components, and many don’t belong in the current recycling streams. Solving that at scale means automating the process. We can't put the burden on the consumer; we have to design systems that work without friction.
What role should regulation play in enabling those systems?
Regulation can set boundaries, but companies need to make the economics work. Without a viable business model, sustainability doesn’t scale. In Europe, we often take a very idealistic stance, but when it comes to paying a little more for the greener option, many people choose the cheaper one. We need full value-chain integration and incentives that align environmental goals with economic reality.
“One investor told me, ‘Fire your client.’ If someone isn’t willing to invest in your innovation, don’t waste your time. That advice helped.”
How would you describe the innovation ecosystem in Luxembourg today?
There’s still strong political will to support innovation, but Luxembourg is a small market. We can’t focus on everything. I’d love to see more appreciation for the country’s industrial heritage, which is something we can build on. There’s also a tendency to follow trends, and right now AI is soaking up a lot of attention. But if we want resilience, we have to invest in the hard stuff too, like making urban mining viable.
What’s been the biggest challenge as a founder so far?
Hiring has been tough. We’re working on deeptech that requires technical depth and commercial thinking – we're not just building an app. Finding the right people who are excited about that mission takes time. Another challenge is that large corporates often only engage with innovation when regulation forces them to. Finding affordable operational space for manufacturing hasn’t been easy either.
And the easiest part?
Nothing in a startup is ever truly easy, but we’ve been lucky to find early believers, investors, partners, even people in government who have supported us. Having that network makes a big difference, even when everything else is moving fast and feels messy.
What’s one piece of advice you’d offer to new founders in Luxembourg?
Use the ecosystem. Short distances mean you can talk to the right people, but only if you take the initiative. No one will come to you. You have to go to them.
“Anyone who says they don’t need mentors is missing out on a huge part of the learning curve.”