HELENA stands for “Halide Solid State Batteries for Electric Vehicles and Aircrafts” and aims to accelerate the development of powerful and stable solid-state batteries for electric road vehicles and aircraft. The 15 project participants began their work under the coordination of the CIC energiGUNE research center a good one and a half years ago. Now they are publicizing the first stage of their success: the assembly of a solid-state battery cell with halide electrolyte.
The research team explains that the halide electrolyte has a conductivity of several mS/cm, which makes it possible to operate the cells at high currents and low temperatures. The halide is also suitable for dry room conditions, “which opens up real possibilities for its application in industry”. In principle, the halide electrolyte exhibits high thermal stability for those involved.
The first complete cells of the HELENA project house a lithium metal anode, a halide electrolyte and an NMC622 cathode with a charge of up to 4 mAh/cm2. “With the progress made so far, the HELENA project is well on the way to achieving its goals within the specified time frame,” the statement continues. The project is scheduled to run until the end of May 2026, by which time the researchers have set themselves the goal of developing solid-state batteries with high energy density and performance based on the anode-cathode-electrolyte combination described above.
In addition to CIC energiGUNE, 14 other institutions are part of the HELENA consortium. Specifically, the AIT-Austrian Institute Of Technology, Saint Gobain Recherche, Umicore, Lionvolt, Nederlandse Organisatie Voor Toegepast Natuurwetenschappelijk Onderzoek, the Fraunhofer-Gesellschaft, Customcells, the Rheinisch-Westfälische Technische Hochschule Aachen, Mimi Tech, IFP Energies Nouvelles, Pipistrel Vertical Solutions, Doo Podjetje Za Napredne Letalske Resitve, Leonardo – Societa Per Azioni, Fev Europe and Zabala Innovation Consulting.
“Halide-based solid-state batteries, which are the focus of HELENA, are inherently safer than conventional lithium-ion batteries and other types of solid-state batteries,” says Artur Tron, battery expert at AIT. “Their chemical components are non-toxic and non-flammable, and they have a higher interfacial stability in contact with lithium metal anodes. This prevents the formation of lithium dendrites, which is particularly important as dendrites can cause a short circuit within the cells and therefore pose a safety risk.”