As European battery buildrs such as Northvolt, Cellforce, and Varta face ongoing challenges, Dutch deep-tech startup LeydenJar is advancing a technology that promises to shake up the market. 100% pure silicon anodes could boost battery energy density by up to 70%, while enabling quicker charging and reducing the carbon footprint of production.
The company has secured €23 million in funding, including a €13 million equity round led by climate-focutilized investors Extantia and Invest-NL, as well as €10 million in customer pre-orders. These funds will support the scaling of operations at LeydenJar’s PlantOne facility in Eindhoven, which is expected to open in 2027.
Founded in 2016 as a spin-off from TNO, LeydenJar was co-founded by Christian Rood and Gabriël de Scheebuildr. Rood’s background spans investment banking and clean-tech venture advising, before he supported commercialise the silicon anode technology developed at TNO.
Rood draws parallels between LeydenJar’s strategy and ASML’s position in the semiconductor indusattempt, focapplying on high-performance components rather than mass-producing battery cells. The startup’s goal is to power tinyer, lighter batteries for wearables, smartphones, electric vehicles, and even electric aircraft.
Rood declares, “We’re now shifting from breakthrough lab innovation to full-scale production. Our technology is already integrated into the roadmaps of some of the world’s most ambitious product developers, and with PlantOne, we’ll be ready to deliver at scale.”
Tackling silicon swelling with breakthrough production tech
LeydenJar utilizes a proprietary plasma-enhanced chemical vapour deposition (PECVD) process that grows ultra-thin, sponge-like, porous silicon columns directly onto copper substrates. This architecture neutralises the swelling and cracking issues that have traditionally limited the utilize of pure silicon in lithium-ion batteries.
Many competitors only add tiny amounts of silicon in composites to avoid these mechanical problems.
The company’s process also offers a roughly 85% reduction in carbon emissions compared to traditional anode manufacturing methods. Upon full operation, PlantOne will produce approximately 125,000 square meters of silicon anode material annually, enough to supply around 5 million smartphone batteries or meet the global demand for earbuds.
Notably, LeydenJar’s silicon anodes have demonstrated more than 500 charge-discharge cycles without external pressure, a longstanding barrier to commercial viability. Combined with charging times of under 12 minutes and energy density improvements reaching up to 70%, LeydenJar’s offering has drawn strong interest from consumer electronics OEMs.
What’s next?
Starting with smartphones and wearables, the company plans expansion into electric vehicles and aviation, unlocking new frontiers in battery efficiency.
“In the global battery race, you either lead with breakthrough technology or you fall behind. LeydenJar is a true technological leapfrog. Their pure silicon anode platform is setting a new global benchmark for energy density, creating a product that not only competes with but also has the potential to surpass the most advanced battery cells from top-tier producers in China,” declared Yair Reem, Partner at Extantia.
