A highly efficient hydrogen battery made from affordable materials has been developed by scientists at the Leibniz Institute for Catalysis (LIKAT) in Germany. The battery can store the gas reversibly, allowing for safe transportation and mobile use. Hydrogen is difficult to transport as a gas due to its high explosion risk and low density, so it is usually chemically bound and liquefied for mobile use. The LIKAT team has developed an innovative hydrogen storage system that can chemically store and release hydrogen using a catalytic system, similar to an electric battery but charged with hydrogen instead of electricity.
While chemical hydrogen storage concepts have been developed before, they were not practical due to the need for expensive catalysts based on precious metals such as ruthenium, rubidium, or iridium, and special environmental conditions for hydrogen storage and release. The LIKAT team’s hydrogen battery is based on a catalyst made from an affordable manganese complex, which can store and release hydrogen under uniform conditions. The battery also uses the organic molecule formic acid (HCOOH) as a storage medium for hydrogen.
The first prototype of the hydrogen battery achieved a yield of over 80%, which decreased to 72% after ten cycles. However, the CO2 released during dehydrogenation meant that this was not a closed cycle, where only hydrogen needs to be refilled. The team optimized the system by using the potassium salt of the amino acid lysine instead of lysine, which can absorb 99.9% of the released CO2 and close the battery’s cycle. The optimization increased the efficiency of the hydrogen battery to over 80%, and the released hydrogen gas is highly pure.
This method represents one of the most productive combinations of CO2 binding and formate dehydrogenation based on a non-precious metal catalyst, according to the researchers. The hydrogen battery only needs to be filled with air once at the beginning, and the CO2 remains in the closed cycle. This breakthrough could lead to practical and affordable hydrogen storage and transportation, making hydrogen a more viable energy source.
