CD Laboratory for Oxygen Ion Batteries

The oxygen ion battery is an innovative and promising technology for the large-scale storage of electricity from wind and solar power plants. It is primarily intended for stationary storage applications lasting 4 to 12 hours, does neither require precious metals, nor lithium or cobalt, and is non-flammable. Through fundamental research on suitable electrode materials, this CD Laboratory is making an important contribution to enhance the broader applicability of this technology.

The electrification of the industrial, mobility and heating sectors with renewable power generation technologies offers great potential for climate protection. However, the realization of a sustainable energy supply still faces a fundamental challenge: Electricity production from photovoltaic and wind power plants cannot be time-controlled, meaning energy is not always generated when it is needed. This can become a problem particularly when there is a high proportion of solar and wind power. For example, there may be too much electricity available at midday and less than required in the evening. Energy storage systems can help shift renewable electricity generation over time.

As currently used electrochemical storage solutions, such as lithium ion batteries, are optimized for mobile applications, they are only suitable to a limited extent as stationary storage systems, where large amounts of energy need to be stored and retrieved over longer periods of time – such as daily. Other large-scale storage systems, such as pumped hydro storage, are often dependent on geographical conditions. A lack of storage flexibility leads to the undesirable situation that, with a high level of expansion of wind and solar energy, these sustainable power generation technologies have to be curtailed more and more frequently, leading to the situation that the power plant output has to be reduced, so that no more electricity is produced than can be consumed.

A new type of battery technology developed in 2023 at the Institute of Chemical Technologies and Analytics at TU Wien (the home of this CD Laboratory) could provide a solution: The oxygen ion battery (OIB for short) is an electrochemical solid-state cell that can reversibly store energy at temperatures of 300 to 500 °C by utilizing changes in the oxygen content of its ceramic electrodes. In this process, however, the oxygen is not exchanged with the atmosphere, but is shifted back and forth between the two electrodes of the cell in the form of oxide ions. The elevated temperature is necessary for the oxide ions in the OIB materials to become sufficiently mobile.

OIBs offer various attributes that are particularly important for efficiency and sustainability: Unlike many other battery types, they are neither flammable nor toxic and therefore safe and environmentally friendly. In addition, they can be manufactured primarily from abundant elements. This makes their production inexpensive and not dependent on geopolitically critical raw materials. However, they are still prototypes in their current form and are not yet ready for large-scale use in terms of manufacturing costs and performance efficiency.

This CD Laboratory therefore aims to make an important contribution to the further development of OIBs into powerful, easy-to-produce and scalable high-performance cells. The goal is to enable OIBs to shift the power generation of photovoltaic systems over longer periods of time – for example from midday to evening or even longer. To achieve this, the CD Laboratory is conducting basic research into new, highly abundant electrode materials with particularly promising properties in order to avoid expensive laboratory techniques, which are currently still required electrode manufacturing. The application of advanced analytical techniques, which will be tailored to the special requirements of OIB materials, will further deepen the understanding of the fundamental electro-chemo-mechanics of the involved materials.

The CD Laboratory team is thus striving for an in-depth understanding of the physical, electrical and chemical phenomena essential for OIB production and operation in order to contribute to the establishment of this extremely promising battery technology for stationary electricity storage.