Europe's next battery bet is a silicon anode foil that reaches production at the end of 2026

Silicon is cheap and works well in an anode, and pure silicon cracks: it expands and contracts every time a cell runs and recharges ^[5]. LeydenJar's method is plasma deposition, building an ultra-thin pure silicon foil one tiny layer at a time, which the company says resists the cracking and lifts battery life, charging speed and energy density by up to 50% ^[6]. Rood said that where a pure silicon anode would normally fall apart, this one stays stable, and he called it a wonderful invention ^[7]. His shorter version: "We address the bottleneck in the battery" ^[8].

The factory is in Eindhoven, where ASML and other chip industry players sit ^[9]. Rood said the crossover is what separates the company from a lab result: "once you've demonstrated the principle in the lab, industrialization requires you to work with the semiconductor technology and suppliers" ^[10]. He said the patenting and IP work that comes with that is "much more difficult to do in the US or in China" ^[11].

Commercial-scale production starts at the end of 2026, and reaching that point has taken ten years ^[3][4]. Subtract, and the work began around 2016 ^[12]. A buyer qualifying cells for a 2027 product would be designing around a line that has been running for months.

Powall, in Delft, leaves the cell architecture alone and coats the powders that are the raw material of today's batteries, using commercial-scale equipment it is still developing ^[13]. The granules are micrometres across and the coatings are nanometres thick, applied by atomic layer deposition, with powder and coating carried by gas into a chemical reaction ^[14][19]. "Your battery works less well than before after using it thousands of times - that degrading or aging can be slowed down when you're using a nanocoating," Colen said ^[15]. New materials, he said, "typically have one element which is very good, but they suffer on the durability side" ^[16].

An increasing number of investors and researchers are looking at that nanometre scale, according to the BBC ^[21]. Neither of these two firms is trying to build a whole battery, and both have commercial relationships with customers in Asia ^[17]. So the European part arrives inside somebody else's cell, and a European buyer's purchase order goes where it went last year. Rood said companies like his can fortify Europe's position in what has become a global contest ^[18]. On this evidence, that position is patents, equipment and process knowledge.

The up-to-50% gain is LeydenJar's own figure, and the account carries no independent measurement, no named customer and no volume ^[23]. Rood is not selling certainty either. He said that if this can be made to work it touches many industries, and that it is a risky business ^[22].

Two questions separate a component pitch from a sourcing decision. Which cell part number will carry the improvement, and when can I sample that part. Who measured the gain, the component maker or the cell maker. LeydenJar answers the first with the end of 2026 and the second with itself ^[3][23]. That makes a silicon foil anode a 2027 requalification item and keeps it out of this year's order.