Electrochemistry as a key technology for the energy transition

Electrical energy storage and hydrogen

Decarbonization poses challenges for our modern industrial society. In particular, we will have to decouple our increasingly volatile energy generation and consumption much more strongly through sector coupling and storage options, as well as using hydrogen as a material carrier. Electrochemistry is a key competence for both electrical energy storage and the hydrogen economy.

Alternative cell technologies for energy

While lithium-ion cells are currently used for electrical energy storage in the mobility sector, other cell technologies are conceivable for grid-connected stationary storage, such as that required for primary control power. The background to this includes the changed requirements from operational management and the reduced relevance of gravimetric storage density for the application. Alternative technologies such as zinc-ion and sodium-ion systems are often much cheaper, non-toxic, and safer. At the same time, in contrast to lithium-ion cells, the materials required are classified as noncritical in terms of their availability. Further important questions arise in the field of operating strategies for electrical energy storage systems. New methods for online determination of the state of charge and the state of health of the battery cells are necessary for optimal and long-lasting reliable operation.

Focus on expanding hydrogen transport chain

In the future energy and economic system, hydrogen will be needed for many applications, such as sector coupling, as an energy storage medium and as a material carrier. Due to the wide range of possible uses, increasing the availability of green hydrogen and its distribution is currently the focus of market development.

For hydrogen production to be economically viable, generation plants must be produced cost-effectively. An efficient production route should enable scalable production, process steps that conserve raw materials as well as highly active and and long-term stable electrodes for alkaline water electrolysis. Different concepts are possible for transporting green hydrogen, depending on the production site. Developments of Fraunhofer IFAM include technologies for setting up a hydrogen transport chain from the offshore area to consumers on the mainland. In many cases, these developments, such as barrier layers or sealing materials for tanks or pipes, can also be used for other hydrogen applications.

Cost-effective and resource-saving production of green hydrogen

Electrolysis with anion exchange membranes (AEM) is a new approach. It combines the advantages of alkaline electrolysis, such as high long-term stability and the use of inexpensive and available metals, with those of the proton exchange membrane electrolyzer (PEM-EL), i.e., higher performance, adaptability to volatile loads and gas purity. AEM electrolysis has not yet gained acceptance in industrial applications because the oxygen evolution reaction (OER) involved in the process is too slow and cell volltage required for water electrolysis is high.

The HighHy project addresses these challenges: The German-New Zealand collaboration (funded by the German Federal Ministry of Education and Research, BMBF), is working to develop nickel-manganese compounds as OER catalysts that enable highly efficient AEM electrolysis feasible on an industrial scale. “Together with three New Zealand universities and the University of Bayreuth, we are trying to find the ideal composition for the required catalysts,” says Dr. Christian Bernäcker, head of the Electrochemical Technology group at Fraunhofer IFAM, summarizing the aim of the project.