Themed collection Special issue in honour of Prof. John Kilner’s 75th birthday

Stephen Skinner, Viola Birss, Jennifer Rupp and Roger De Souza introduce the Journal of Materials Chemistry A special issue in honour of Prof. John Kilner’s 75th birthday.

This article reviews the state of the art – from the experimental and computational data available to the models, origins and possible uses – in the field of chemical strain of oxide materials (primarily those for elevated-temperature applications).

Ionic conductivity is a critical parameter required for superionic conductors to be successfully applied as solid electrolytes in all-solid-state batteries.

In this review, we consider the detrimental effects of Si-contamination on electrochemical applications, broadly conceived, in which both ions and electrons play key roles in device operation and where exchange of oxygen between the gas and solid phase is likewise essential for operation.

This review summarizes recent progress on dual-phase oxygen transport membranes. Existing challenges, research strategies and future application areas are discussed.

We present an overview on the development of various mixed conducting perovskite-type related structure metal oxides and other crystal structures, and composite cathodes for advanced solid oxide fuel cells.

The study of the oxygen incorporation and diffusion in lanthanum manganite thin films is presented by means of novel isotope-exchange atom probe tomography, allowing a direct quantification of the enhancement of grain boundaries' oxygen kinetics.

Tetragonal Li₇La₃Zr₂O₁₂ (LLZO) was halogenated to form cubic LLZOF(Cl) via a low temperature solid state synthetic route using PTFE and PVC polymers.

Non-equilibrium thermodynamics describe the current–voltage characteristics of electrochemical devices.

In mixed-conducting LaNiO_3−δ/La₂NiO_4+δ bilayers the deposition conditions determine the film microstructure and the oxygen defect concentration at the interface (and ) building up an electronic barrier which induces a memristive behavior.

Working solid oxide fuel cell anodes based on conducting ceramic scaffolds with different infiltrated electrocatalysts have been investigated by operando Raman spectroscopy and EIS. Carbon deposition depends on electrical load and electrocatalyst.

Co diffusion from LCO into LLTO onsets around 300 °C in air, in the absence of any secondary phases. Co diffusion into LLTO decreases the charge transfer resistance, by forming a mixed electronic and ionic conducting zone near the interface.

First time demonstration of epitaxially stabilised δ-Bi₂O₃ phase in vertically aligned nanocomposite thin films, exhibiting very high ionic conductivities of up to 10⁻³ S cm⁻¹ at 500 °C.

A PBC–GDC composite with coherent interface structure shows remarkable ORR activity and low polarization resistance under IT-SOFC service conditions.

This work focuses on understanding the oxygen-ion transport through the mixed Grain Boundaries (GBs) present in yttria-stabilized zirconia (YSZ), a common solid oxide fuel cells (SOFCs) electrolyte.

High-performance and stability for protonic ceramic fuel cell cathode applications are realised in a self-assembled nanocomposite material Ba_0.5Sr_0.5(Co_0.7Fe_0.3)_0.6875W_0.3125O_3−δ (BSCFW) through interplay of single and double perovskite phases.

Pr and Mn infiltrated oxide nanoparticles are confirmed as excellent candidates for boosting the performance of standard lanthanum strontium manganese oxygen electrodes.

Fast oxide-ion conductivity in Bi_3.9Sr_0.1NbO_8−δCl is reported for the first time, and this oxide is stable under a reducing atmosphere.

High-voltage Li metal solid-state batteries are in the spotlight as high energy and power density devices for the next generation of batteries.

Li distribution within the battery electrode material is quantified using neutron depth profiling (NDP) as a function of depth in real-time.

We report a new strategy to grow nano-columnar La₂NiO₄ thin films with an enlarged specific surface area. In combination with modifications of the surface chemistry, we strongly improved the oxygen exchange activity of this promising electrode material.

Gaining insight into the reconstruction of perovskite oxides that promote oxygen evolution reaction (OER) is critical for developing stable and high-efficiency electrocatalysts.

Hetero-structured DP/RP-SFCuM perovskite composites with exsolved Fe and Cu metallic nanoparticles exhibit excellent electrochemical performance in CO₂ electrolysis reactions for high performance solid oxide electrolysis cells.

We report a comprehensive first-principles DFT study on (electro)chemical stability, intrinsic defects, and ionic conductivity improvement by halide doping of Na₃SbS₄ electrolyte for all-solid-state Na batteries.

Ruddlesden–Popper phase oxide with exsolved Co–Fe alloy nanoparticles uniformly distributed on the surface (Co–Fe–STCF) exhibited outstanding activity towards CO₂ electrolysis at elevated temperature.

Schematic representation of possible oxygen electrochemical reduction pathways of self-assembled multi-phase cathodes with a synergistic ensemble effect.

Limited reaction between Li_0.3La_0.5TiO₃ and molten lithium sufficiently modifies the properties of the lithium anode, improving the overall performance of solid-state lithium batteries.

Free-standing garnet based ceramic cathodes with tailored microstructure enable dramatically increased full-cell capacity.

La_0.7Sr_0.2Ni_0.2Fe_0.8O₃ (LSNF), having thermochemical stability, superior ionic and electronic conductivity, and structural flexibility, was investigated as a cathode in SOECs.

Substitution with Y affects phase formation and the local cation stoichiometry of the Ce-rich and Fe-rich phases of BaCe_1−(x+z)Fe_xY_zO_3−δ self-generated composites. This is of particular importance for the water uptake in these compounds.

Temperature and p(O₂) dependences of the oxygen exchange kinetics of SOFC cathode materials were correlated with point defect concentrations. Defect chemical contributions were identified as a major part of effectively measured activation energies.

Nanostructured La_0.6Sr_0.4CoO_3−δ (LSC) thin film electrodes with higher porosities exhibit better electrochemical performance and long-term stability owing to enhanced surface exchange properties and suppressed cation diffusion across interfaces.

Record high performance and longevity is reported for a butane-fueled low-temperature-operating solid oxide fuel cell (LT-SOFC). Affordable catalysts, Cu and CeO₂, were incorporated into a thin-film-based SOFC to enable this remarkable enhancement.

We reveal the effects of cation doping and dopant-vacancy clustering on Na-ion conductivity in the anti-perovskite Na₃OCl solid electrolyte through atomistic simulations.

Crystallization of a perovskite mixed conductor is coupled to oxidation, which drives defect chemistry, ion coordination, polyhedra alignment, hierarchical microstructure, and property evolution – including a boost to electrical conductivity.

Optimum (La_0.2Nd_0.2Sm_0.2Ca_0.2Sr_0.2)MnO₃ exhibits excellent high-temperature resistance to elemental segregation and chemical compatibility with 8YSZ while maintaining good electrical conductivity.

We explore the crystal vibrations of Li₃N and their connection to the high-temperature superionic transition.

In situ exsolved Fe–Ni nanoparticles anchored on a (La_0.3Ca_0.7)_0.95Fe_0.7Cr_0.25Ni_0.05O_3−δ parent perovskite surface significantly enhance the CO oxidation kinetics, thus reaching excellent activity of the CO₂ reduction reaction.

Combining electrochemical measurements with in situ and ex situ photoelectron spectroscopy and simulations to detect the formation of cobalt oxyhydroxide during the oxygen evolution reaction.

Formation of sodium superoxide on the anode evidences the existence of O₂/O₂⁻ crossover processes. Sn₄P₃ alloy provides greater stability and less surface reactivity than metallic Na anode.

Reactive sintering of composites for use as OTM is a promising method enabling lower sintering temperatures as well as low-cost raw materials. Phase formation and distribution during sintering plays a vital role in the performance of the composites.

Oxygen diffusion in CaTiO₃ is revealed through molecular dynamics (MD) simulations to have a smaller activation enthalpy in the high-symmetry phase.

We show manufacturing of 25 cm² BZCY half-cells by tape-casting of assemblies with electrolyte thickness 10–20 μm. BaY₂NiO₅ transient liquid phase formation is analysed and proton conductivity with values of σ = 0.003 S cm⁻¹ at 600 °C is shown.

With a new photoelectrochemical cell we perform operando X-ray absorption spectroscopy on SrTaO_xN_y during photocatalytic solar water splitting. Operando characterisation proves to be an invaluable tool for the design and discovery of novel materials.