Paul van Gerven
1 April

The Dutch high-tech ecosystem has sprouted seven companies that are looking to improve lithium-ion battery technology, or market completely different battery designs.

The battery has entered a golden age. It has already been indispensable for a range of applications, but with the anticipated transition to electric driving and increasing adoption of renewable energy sources, the world is rushing to increase battery manufacturing capacity. For example, global lithium-ion cell manufacturing is expected to rise from 95.3 GWh per year in 2020 to 410.5 GWh per year in 2024, according to market research firm Globaldata.

The world will also need better batteries. Researchers and companies are frantically trying to improve the lithium-ion cells or come up with alternative technology that’s better suited for particular applications. After all, buffering supply and demand in the electrical grid is a different ball game than getting an electric car to drive as far as possible on a single charge.

The Netherlands plays no role in battery manufacturing. There are several companies, such as Cleantron, SuperB and Eleo, that assemble battery modules for niche applications. VDL Nedcar is considering automotive battery pack assembly as part of its efforts to replace the impending loss of the BMW business. But there’s no battery cell or A-to-Z battery manufacturing in the Netherlands.

On the technology front, however, seven Dutch companies have emerged that have something to contribute. The applications they target are remarkably varied, ranging from materials and components to full-fledged batteries and manufacturing equipment.

Battolyser

A spinoff from Delft University of Technology (TU Delft), Battolyser has developed, well, a battolyser. This device stores electricity like any battery, but it can also split water into hydrogen en oxygen when it’s fully charged. A simple combination of a regular battery and an electrolyzer could do the same, but the battolyser “does it better and at lower costs in situations where it really matters,” says its inventor, Fokko Mulder, professor at TU Delft’s Chemical Engineering department.

The key is the ability to quickly react to electricity price fluctuations, which are expected to become more pronounced as more renewable energy sources are installed. While conventional electrolyzers can’t easily be turned on and off, the battolyser can instantly switch between hydrogen production and discharging the battery. So, when electricity prices are low, the battolyser is put to work for producing (green) hydrogen, a valuable compound used in a range of (cleantech) applications. When prices are becoming too high, the device can not only discontinue hydrogen production, but it can actually start selling electricity by discharging the battery.

Battolyser, headquartered in Schiedam, is backed by Koolen Industries, Proton Ventures and Delft Enterprises (which is part of TU Delft) and has been commissioned to install a device at Nuon’s Magnum power plant in Eemshaven.

Delft IMP

Batteries are just one application for the powder coating process developed at TU Delft and currently being commercialized by spinoff Delft Intensified Materials Production (Delft IMP). Coating cathode and anode materials enhances their durability, resulting in extended battery life. Other advantages include higher energy density, increased battery safety and the option to use cheaper materials without performance loss.

Delft IMP adapted the atomic layer deposition (ALD) process to give powder particles a ‘nanoshell’ of desired thickness. While traveling through a tubular reactor, the particles come into contact with gaseous precursors, which react with their surface. Thus, a coating is formed atomic layer by atomic layer, the thickness of which depends on the diameter and length of the reactor’s tubes. This process is continuous and capable of industrial production rates.

The company sells the reactors, not the coated materials.

Elestor

Elestor’s mission is to build a storage system with the lowest possible storage costs per kWh. To accomplish that, the Arnhem-based company is building on technology that was developed by NASA decades ago: the redox flow battery. Lithium-ion cells are no match for these devices when it comes to grid-scale energy storage, on account of their scalability, superior lifetime and cost of ownership.

In a nutshell, these redox flow batteries ‘store’ electrons in a chemical compound, which is synthesized whenever there are electrons (ie electricity) in excess. The electrons are released when needed through the same chemical reaction in reverse. Elestor’s flow battery turns hydrogen bromide into hydrogen and bromine when charging. These active materials are readily available, cheap and enable both a high energy and power density.

Supported by the European InnoEnergy fund, Elestor was founded in 2014. The Arnhem-based company later attracted investments from Koolen Industries and Enfuro Ventures.

E-magy

The focus of Broek-op-Langedijk-based E-magy is on lithium-ion battery anodes. These are traditionally made from graphite, even though it has been known for a long time that silicon would be vastly superior in terms of energy density. The reason is that silicon can’t handle the mechanical stress associated with repeatedly taking in and letting go of lithium ions.

E-magy’s parent company, RGS Development, created a casting process that results in ‘nanosponge’ silicon, which doesn’t crack under the pressure of entertaining guests. This material can achieve a 40 percent higher energy density than traditional graphite anodes while shortening charging times and reducing the cost of production.

Focusing on the electric-vehicle market, E-magy currently has one production facility operational and is making preparations to expand. The company is targeting to churn out 3,000 tons of nanoporous silicon annually, enough to supply up to half a million EVs each year.

Electron microscope image of E-magy’s nanoporous silicon. Credit: E-magy

Leydenjar

Like E-magy, Leydenjar has set its sights on silicon anodes for lithium-ion batteries. Unlike E-magy, however, it’s not selling the material but the manufacturing equipment. The company’s core technology was originally developed by PV research institute ECN in hopes of obtaining better-performing solar cells. The nanotextured silicon, produced using a plasma-enhanced chemical vapor deposition (PECVD) process, didn’t do well in that particular application but, as it turns out, makes for fine anodes. Leydenjar claims an increase in energy density of up to 70 percent compared to graphite anodes.

The Leiden-headquartered company initially spent a lot of time to prove the real-world advantages of its anode manufacturing process, as well as its commercial viability. Next, it established a pilot production line in Eindhoven, allowing for customers to put in a sample order to get a taste of the technology. The final step will be to develop roll-to-roll deposition equipment optimized for production.

Lionvolt

Lionvolt wants to become the first Dutch manufacturer of battery cells – but not just any battery cells. The Holst Centre spinout has successfully demonstrated a proof of concept of a 3D solid-state thin-film lithium-ion battery. It consists of a foil, covered with an array of micropillars, each coated with thin layers of battery materials: lithium-storing electrodes sandwiching an electrolyte. For simplicity’s sake, each pillar can be considered a tiny battery.

Lionvolt’s 3D solid-state lithium-ion battery on foil.

This design has three main advantages. One: the lithium ions need to travel relatively short distances, translating into faster charging and de-charging times. Two: there’s no liquid electrolyte involved, meaning a longer lifespan and little to no danger of fires or explosions. And three: the design is inherently lightweight.

Leveraging these advantages, Lionvolt will initially target the wearables market. In the longer term, larger versions of the 3D solid-state batteries will be developed for automotive and other markets.

SALD

Eindhoven-based SALD has a lot of similarities with Delft IMP. Both companies are developing ALD production equipment for a variety of applications. When used for contemporary lithium-ion battery manufacturing, the tools of both companies are used to apply a protective coating to the electrode materials. The processes involved are quite different, however.

SALD’s core technology is another ALD variety capable of high-throughput production, called spatial ALD. It involves leading a moving substrate past different precursor-gas zones, thus step by step building up a nanolayer.

Unlike Delft IMP, SALD applies the coating after depositing the powdered electrode materials on a substrate. This means that the particle surfaces are not covered entirely. For example, where particles touch, no coating can grow. According to SALD, this improves the ease with which electrons can move through the electrode.