Theion continues to develop sulfur battery

Theion is researching sulfur crystal batteries and continues to grow. The Berlin-based company develops and manufactures sulfur crystal batteries for applications in stationary storage, aerospace, portable devices, wearables, and vehicles on land, water, and in the air. By using sulfur in its crystalline form, an abundant material without harmful extraction practices and at 99% lower costs compared to modern cathode materials, Theion's cells aim to triple usage lifespan and range while reducing costs by a factor of three. In addition to increasing the cycle life of the cells to standard levels, the sustainable production processes developed by Theion require significantly less energy for manufacturing and recycling, with lower space and capital requirements than current gigafactories, all while maintaining similar production performance.

The 19 experts in their fields come from ten nations. As part of its expansion strategy, the startup has moved into a new 1,800-square-meter building in Berlin's leading science and technology park Adlershof. On four floors near the Humboldt University of Berlin campus, the Theion team will further advance the development of sulfur crystal batteries in the coming years. Dr. Ulrich Ehmes, CEO of Theion GmbH, explains:

"After successful tests with button cells, we have produced the first single-layer pouch cells. To keep the pace up and tackle the next milestones in a focused manner, it was important to bring the entire team together in one place."

He sees great potential here and adds:

"The potential of our technology is enormous. Either in combination with lithium for mobile applications or with sodium for stationary storage. We will continue to strengthen our team for the exciting challenges in product and process development."

For mobile applications, Theion combines a monolithic sulfur cathode with a modified lithium metal anode. The monolithic sulfur cathode is prepared to have a highly hierarchical morphology and an artificial percolation network. This enables high loading and high utilization factor of the active materials. To protect the cathode from polysulfide shuttles, the typical challenge in lithium-sulfur batteries, Theion protects the polycrystalline sulfur in the cathode with a special, easy-to-apply coating that negates the insulating character of sulfur.

Button cells are to be followed by pouch cells

The next development steps are the transfer of process innovations from button cells to pouch cells and the construction of multilayer pouch cells to increase the energy density of the battery. For the first commercial cells, Theion aims for a gravimetric energy density of 500 Wh/kg with a lifespan of 500 charge cycles. Based on current material prices, Theion’s new technology can significantly reduce costs even for small production volumes. Additionally, there is the strategic advantage of complete supply autonomy and thus independence from sourcing cathode active material from Asia. Corresponding patents to protect the company's most important intellectual property have been granted in recent months. Further patents are in the application process.

What does that mean?

Sulfur has the advantage of being abundantly available in crystalline form – and thus could become an exciting alternative for batteries. Here's hoping that the transformation from button cells to pouch cells is successful and that Theion can create an alternative for all applications.