The Role of Renewable Energy in a Sustainable Future

It is nowadays widely acknowledged that renewable energy sources like wind power and photovoltaics (PV) do play an essential role in transitioning to a sustainable energy supply. 

The Challenge of Intermittent Energy Output

However, a main challenge lies in their intermittent energy output, particularly with PV peaking midday and struggling to meet evening demand. In the load profile of a power grid, this leads to a characteristic curve shape, which is often referred to as the "duck curve" (see Fig. 1). In some regions, the imbalance described by the duck-curve already implies that electricity producers are less inclined to expand PV capacities, as these yield little additional profit. This development poses a growing issue as it hampers the urgently needed decarbonization of the electricity production sector.

Storing electrical energy in batteries is a suitable way out of this dilemma, as large stationary batteries are able to shift large amounts of energy from midday to the evening hours. However, current electrochemical storage solutions encounter several challenges, fostering a high demand for novel, innovative battery concepts with key attributes like high safety, non-toxicity, usage of abundant materials, and low price.

A New Battery Technology: The Oxygen-Ion Battery (OIB)

Oxygen Ion Batteries (OIBs) are a novel battery technology, which has been recently invented at TU Wien’s Research Unit Technical Electrochemistry. [https://www.tuwien.at/tu-wien/aktuelles/news/news/neue-erfindung-die-sauerstoff-ionen-batterie]. An OIB is a solid oxide electrochemical cell, which uses oxygen stoichiometry changes in its ceramic electrodes to reversibly store energy at elevated temperatures of 300 – 500 °C. 

Safe, Environmentally Friendly, and Resource-Efficient

Comprising solely inorganic oxides OIBs are – in contrast to established battery types – non-flammable and have no need for toxic components. Additionally, they can be primarily made from highly abundant chemical elements, thus avoiding the socio-economic issues of currently existing battery technologies. 

In order to turn this rather young battery technology into a game changer for stationary electricity storage, OIBs must be further developed into high performance cells that are based on highly abundant materials and can be produced using scalable and inexpensive methods.

Research at the CD Laboratory for Oxygen-Ion Batteries

The CD Laboratory for Oxygen Ion Batteries propels this development by conducting targeted basic research to achieve a level of maturity that renders OIBs suitable for large-scale, multi-hour electricity storage. The team, consisting of two PhD students, two PostDocs, and Alexander Opitz as the head of the CD lab (see Fig. 1), focuses on developing novel, abundant electrode materials with high capacity and voltage for integration into scalable OIBs via powder-based fabrication techniques. 

Advanced analytics on electrode materials, including in-situ chemical expansion measurements and X-ray absorption measurements, will elucidate the electro-chemo-mechanics of these electrodes. Prototype cells will be assembled and tested with industrial partner VERBUND, combining material innovation, tailored processing methods, and advanced characterization.

Contribution to the Energy Transition

With this approach, we aim to enable the maturing of OIBs from the current model-type level to a scalable, high performance electricity storage solution. By gaining an in-depth understanding of the key physical, electrical and chemical phenomena during the processing and operation of OIBs, the CD Laboratory for Oxygen Ion Batteries will make a significant contribution to establishing OIBs as a cornerstone for the urgently needed stationary electricity storage and thus serve as an accelerator for the expansion of renewable energy sources.