Solid State Ionics: Defects Bridging Materials for Energy and Information Technologies

This symposium will focus on recent developments in the field of Solid State Ionics for functional materials for energy applications and data storage. The impact of the materials’ fundamental electronic and ionic transport properties on the device performance will be at the centre of the discussions.

Scope:

Tailoring functional materials for technologies from energy conversion to gas sensing and data storage requires comprehensive control of the intricate interplay of electronic and ionic charge carriers in these materials. The charge carriers, in the form of point defects, often interact with surfaces or extended defects such as grain boundaries, with the resulting defect concentration and mobility governing charge and mass transport at the device level. To maximise the materials’ performance, it is quintessential to understand the mechanisms of how defects affect the materials during their manufacturing process, operation and unwanted degradation processes. Such detailed insights require advanced characterisation techniques in the form of complementary (in-situ/operando) experiments and computational simulations.

The aim of this symposium is to explore the direct connection between the fundamental defect thermodynamics and the resulting device performance for applications including, for example, batteries, fuel cells, electrolysers, electrocatalysts, photovoltaics, gas sensors, membranes, memristive devices, and ionic synapses. In particular, the symposium will address the role of defects at complex interfaces, such as those found in all-solid-state batteries (where the interplay between ionic and electronic charge carriers at solid-solid interfaces critically impacts device performance) or in exsolution catalysts (where defects in the parent oxide are crucial for the formation of a metal/oxide interface). Additionally, the symposium will focus on kinetics and non-equilibrium processes, such as defect evolution under dynamic conditions, which are increasingly relevant for real-world applications.

While the methodological toolkit of the Solid State Ionics community for characterising defects is increasingly sought after by other communities, e.g., with a focus on electrochemical applications, the ideal scenarios of dilute defects in the defect-chemical framework are often in stark contrast to real materials from these fields of research where complex, heterogeneous co-existing phases are common. The consideration of defect interactions promises to be a decisive step in widening the scope of the Solid State Ionics field. This symposium will serve as a forum to discuss these current developments and promote the transfer of defect thermodynamics to other fields of research.

The interdisciplinary nature of Solid State Ionics is also becoming increasingly evident, with defect engineering playing a key role in emerging fields such as neuromorphic computing and ionic synapses. Solid State Ionics provides the fundamental framework linking these diverse application areas through a common description of defect-mediated transport. Furthermore, the integration of artificial intelligence (AI) tools for defect prediction and optimization is opening new avenues for accelerating materials discovery and design. Sustainability and circularity are also critical drivers in the development of next-generation materials. This symposium will highlight how defect engineering can contribute to the use of earth-abundant elements, improve recyclability, and enable scalable manufacturing processes, particularly for energy technologies such as batteries and fuel cells.

By addressing these challenges and opportunities, the symposium on Solid State Ionics aims to bridge the gap between fundamental defect science and its application in sustainable energy and information technologies.

Hot topics to be covered by the symposium:

Papers are solicited on (but not limited to) the following topics:

• Defect chemistry and defect engineering in functional materials with additional focus on sustainability
• Electrode kinetics, electro-catalysis, and exsolution catalysts
• Interfaces: solid/solid, solid/liquid and solid/gas
• Advanced characterization tools of solid state ionic materials and devices, such as in situ/operando techniques
• Advances in computational modelling of atomistic transport across length and timescales
• Ion-assisted phenomena incl. iontronics, ferroelectrics, etc.
• All-solid-state devices – e.g.: solid oxide fuel cells and electrolyzers (SOFCs/SOECs), solid state batteries, thermoelectric devices, memristors, gas sensors, oxide photovoltaic cells, etc.
• Thin-film based solid state devices
• From dilute defect thermodynamics to real-world applications: The role of defect interactions
• Solid State Ionics governing mechanisms in materials processing and degradation

Confirmed invited speakers:

• Miguel Laguna – Universidad de Zaragoza – Solid Oxide Cells
• Julian Dailly – EIFER – Fabrication and testing protonic ceramic cells
• Wendelin Deibert – Research Center Jülich - Fabrication of protonic ceramic cells
• Aayan Banerjee – University of Twente – Modeling protonic ceramics
• Qiyang Lu – Westlake University – Ionic defects as essential building blocks to enable tuning of properties of functional oxides
• Kimberly See – Caltech – Superionic conduction in sulfides for solid-state batteries
• Saneyuki Ohno – Tohoku University, Japan, Fabrication of next-generation solid-state batteries
• Stefan Freunberger – ISTA Austria – Marcus kinetics control singlet and triplet oxygen evolving from superoxide
• Bilge Yildiz – MIT – Protonic Electrochemical Synapses for Neuromorphic Computing