New H2 carrier stable even without pressure

22.07.2025

Source: E & M powernews

A new type of liquid carrier for hydrogen remains stable even at room temperature. Researchers from Switzerland and Japan want to use it to simplify transportation and storage.

Until now, the transportation and storage of hydrogen has presented energy companies with major challenges. The gas usually has to be stored under high pressure or at very low temperatures. This is complex, expensive and associated with safety risks. An international research team involving the Swiss Federal Institute of Technology in Lausanne (EPFL) has now developed a liquid that can safely bind and release hydrogen even at room temperature.

The liquid is created by combining two hydrogen-rich substances. In the right mixture, it remains permanently liquid - even without pressure or cooling. It does not crystallize even at minus 50 degrees Celsius. The researchers see this as a possible replacement for previous systems with pressurized containers or cryogenic liquefaction.

Technical advantages for energy companies

According to the EPFL, the new carrier medium achieves a hydrogen density of 6.9 percent and therefore already meets several technical targets set by the US Department of Energy for 2025. The stored hydrogen can be released at temperatures as low as 60 degrees Celsius. According to the scientists, the release takes place with virtually no impurities. Only part of the mixture is decomposed in the process, making it basically reusable.

The liquid remains stable for weeks as long as it is stored in a dry place. Its comparatively low density also makes it easier to handle and transport. According to the researchers, this opens up a new option for applications where hydrogen storage was previously out of the question for technical or economic reasons - for example in decentralized supply or at temporary feed-in points.
The process was developed by the working groups led by Andreas Züttel at EPFL and Satoshi Horike at Kyoto University. Other partners involved were the materials research institute Empa in Switzerland and the Vidyasirimedhi Institute of Science and Technology in Thailand. The project was funded by several Japanese programs, including "Supraceramics" and "JST-ALCA-Next".

Relevance for hydrogen strategy

It remains to be seen when and on what scale the carrier liquid can be used commercially. The researchers believe that the development could nevertheless be of interest to energy suppliers, grid operators and storage operators - for example as a simple solution for temporary storage or as a flexible component of power-to-gas concepts.

The results of the research work were published in the article "Deep Eutectic Solvents Formed by Complex Hydrides: A New Class of Hydrogen-Rich Liquid"in the journal Advanced Materials.

Author: Davina Spohn