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The drawbacks of conventional channel-rib flow fields and gas diffusion layers (GDLs) significantly limit the mass transfer and water management capability of proton exchange membrane fuel cells (PEMFCs), impacting volumetric power density. We report a GDL-less design of electrode-flow field integration comprised of graphene-coated Ni foam and ultrathin (9.1 μm) carbon nanofiber film as an alternative to conventional channel-rib flow fields and GDLs, which substantially reduces membrane electrode assembly volume (90%), reactant transport distance (96%), and concentration impedance (88.6%), resulting in a remarkable 50% power density increase. The GDL-less design provides an effective strategy for the rational design of integrated electrode-flow field and will guide the future development of PEMFCs for their practical applications in energy conversion technologies. We estimate that the peak volumetric power density a PEMFC stack employing GDL-less design can achieve is 9.8 kW L−1, representing an increase of more than 80% compared with the state-of-the-art commercial PEMFC stack.

For hydrogen to play a meaningful role in a sustainable energy system, all elements of the value chain must scale coherently. Advocates support electrolytic (green) hydrogen or (blue) hydrogen that relies on methane reformation with carbon capture and storage; however, efforts to definitively choose how to deliver this scaling up are premature. For blue hydrogen, methane emissions must be minimized. Best in class supply chain management in combination with high rates of CO2capture can deliver a low carbon hydrogen product. In the case of electrolytic hydrogen, the carbon intensity of power needs to be very low for this to be a viable alternative to blue hydrogen. Until the electricity grid is deeply decarbonized, there is an opportunity cost associated with using renewable energy to produce hydrogen, as opposed to integrating this with the power system. To have a realistic chance of success, net zero transition pathways need to be formulated in a way that is coherent with socio-political-economic constraints.

With the rapid growth and development of proton-exchange membrane fuel cell (PEMFC) technology, there has been increasing demand for clean and sustainable global energy applications. Of the many device-level and infrastructure challenges that need to be overcome before wide commercialization can be realized, one of the most critical ones is increasing the PEMFC power density, and ambitious goals have been proposed globally. For example, the short- and long-term power density goals of Japan’s New Energy and Industrial Technology Development Organization are 6 kilowatts per litre by 2030 and 9 kilowatts per litre by 2040, respectively. To this end, here we propose technical development directions for next-generation high-power-density PEMFCs. We present the latest ideas for improvements in the membrane electrode assembly and its components with regard to water and thermal management and materials. These concepts are expected to be implemented in next-generation PEMFCs to achieve high power density.

An electrochemical model is developed to predict the performance of ceria-based

Lithium metal anodes are of great interest for advanced high-energy density batteries such as lithium-air, lithium-sulfur and solid-state batteries, due to their low electrode potential and ultra-high theoretical capacity. There are, however, several challenges limiting their practical applications, which include low coulombic efficiency, the uncontrollable growth of dendrites and poor rate capability. Here, a rational design of 3D structured lithium metal anodes comprising of in-situ growth of cobalt-decorated nitrogen-doped carbon nanotubes on continuous carbon nanofibers is demonstrated via electrospinning. The porous and free-standing scaffold can enhance the tolerance to stresses resulting from the intrinsic volume change during Li plating/stripping, delivering a significant boost in both charge/discharge rates and stable cycling performance. A binary Co-Li alloying phase was generated at the initial discharge process, creating more active sites for the Li nucleation and uniform deposition. Characterization and density functional theory calculations show that the conductive and uniformly distributed cobalt-decorated carbon nanotubes with hierarchical structure can effectively reduce the local current density and more easily absorb Li atoms, leading to more uniform Li nucleation during plating. The current work presents an advance on scalable and cost-effective strategies for novel electrode materials with 3D hierarchical microstructures and mechanical flexibility for lithium metal anodes.

Hybrid redox flow cells (HRFC) are key enablers for the development of reliable large-scale energy storage systems; however, their high cost, limited cycle performance, and incompatibilities associated with the commonly used carbon-based electrodes undermine HRFC’s commercial viability. While this is often linked to lack of suitable electrocatalytic materials capable of coping with HRFC electrode processes, the combinatory use of nanocarbon additives and carbon paper electrodes holds new promise. Here, by coupling electrophoretically deposited nitrogen-doped graphene (N-G) with carbon electrodes, their surprisingly beneficial effects on three types of HRFCs, namely, hydrogen/vanadium (RHVFC), hydrogen/manganese (RHMnFC), and polysulfide/air (S-Air), are revealed. RHVFCs offer efficiencies over 70% at a current density of 150 mA cm–2and an energy density of 45 Wh L–1at 50 mA cm–2, while RHMnFCs achieve a 30% increase in energy efficiency (at 100 mA cm–2). The S-Air cell records an exchange current density of 4.4 × 10–2mA cm–2, a 3-fold improvement of kinetics compared to the bare carbon paper electrode. We also present cost of storage at system level compared to the standard all-vanadium redox flow batteries. These figures-of-merit can incentivize the design, optimization, and adoption of high-performance HRFCs for successful grid-scale or renewable energy storage market penetration.

Nanostructure engineering is an effective approach to enhance the electrochemical performance of energy devices. While the high surface area of nanoparticles greatly enlarges the density of reaction sites, it often also leads to relatively rapid degradation as the particles tend to coarsen to reduce their high surface energy. Therefore, a nickel/gadolinia-doped-ceria (CGO) cermet electrode is studied, with a novel porous nanostructure consisting of nanoscale Ni (100 nm) and CGO (50 nm) crystallites, cosintered from nanocomposite precursor agglomerate particles. This electrode combines both high performance and excellent durability, with a total area-specific resistance (ASR) of 0.11 Ω cm2at 800 °C and a stable ASR with up to 170 h ageing in humidified 5% H2–N2. Post-test analysis by 3D tomography shows that nickel coarsens and is responsible for the initial increase in ASR. However, the subsequent electrochemical performance is stable because reaction at the double phase boundaries (DPBs) on the surfaces of nanoscale CGO becomes dominant and is resistant to ageing. At this stage, the coarsened Ni network is also stabilized by the surrounding nanostructure. The dominant role of the DPB reaction is supported quantitatively using a continuum model with geometrical parameters obtained from 3D tomography.

Membranes with fast and selective ion transport are widely used for water purification and devices for energy conversion and storage including fuel cells, redox flow batteries and electrochemical reactors. However, it remains challenging to design cost-effective, easily processed ion-conductive membranes with well-defined pore architectures. Here, we report a new approach to designing membranes with narrow molecular-sized channels and hydrophilic functionality that enable fast transport of salt ions and high size-exclusion selectivity towards small organic molecules. These membranes, based on polymers of intrinsic microporosity containing Tröger’s base or amidoxime groups, demonstrate that exquisite control over subnanometre pore structure, the introduction of hydrophilic functional groups and thickness control all play important roles in achieving fast ion transport combined with high molecular selectivity. These membranes enable aqueous organic flow batteries with high energy efficiency and high capacity retention, suggesting their utility for a variety of energy-related devices and water purification processes.

Incorporating nanoparticles into SOC electrode is a viable method to improve the electrochemical performance. In this work, nanoparticles of NiO and gadolinia-doped ceria (CGO) approximately 10 nm in diameter fabricated using a continuous hydrothermal flow synthesis are made into nano-structured SOC fuel electrodes via mixing and co-sintering. Both the Ni and CGO are of 50-100 nm in diameter in the final electrode. FIB-SEM 3-D tomography is carried out on the nanoscale Ni-CGO electrode which has been aged for 70 h, showing a high active triple phase boundary density of 3 um-2 and a high active double phase boundary density of 2 um-1. The total polarisation resistance of the electrode is stable at 0.20 O cm2 under open circuit conditions at 800 degC annealing in humidified 5% H2-N2.

A new structure of Ni/gadolinium-doped ceria (CGO) is prepared by a highly tuneable and facile combination of electrospinning and tape-casting method. The structure consists of a network made by continuous Ni fibres and filled in with CGO matrices. When used as the anode of solid oxide fuel cell (SOFC), though it has a lower triple phase boundary (TPB) density, it exhibits better performance compared with impregnated and cermet Ni/CGO with higher nickel loading. An algorithm is developed to determine the ceria-pore double phase boundary (DPB) density with different distance from nickel phase. Using the results, the relative electrochemical reaction rate on DPB and TPB of three different electrodes are calculated and proves that fibre-matrices structure has the morphology advantage of efficiently making use of all ceria-pore DPB. The relative contribution of DPB and TPB in anode reaction of SOFC is quantified in the first time and the importance of DPB is further stressed. This work provides new inspirations in material design of SOFC/SOEC and develops a novel strategy to evaluate the performance of electrodes quantitatively.

Nickel- lanthanum- co-doped compositions of strontium titanate have been synthesized and characterized by a scaleable liquid-based synthesis that may offer an alternative to conventional solid-state synthesis. La0.52Sr0.28Ti0.94Ni0.06O3 is synthesized from soluble precursors followed by calcination in air. The materials can be made phase pure at temperatures as low as 1250degC, as highlighted by X-ray diffraction, and nickel exsolves in hydrogen in the same way as solid-state-synthesized material. The particle size can be varied by calcination temperature and ball milling between 2 um and 20 um. The material is then measured electrochemically by electrochemical impedance spectroscopy and 4-point DC conductivity. A reduction in particle size from 20 um to 9 um results in a large improvement in impedance response measured.

•A neural network driven model is presented for proton exchange membrane fuel cells.•The experimental results are replicated with high accuracy.•Computational speed matches existing hierarchical models with preserved nonlinearity.•High gas flow rate can be detrimental to fuel cell performance under low humidity.•80% of anode catalyst layer is found to generate little current, especially near the inlet.

Lithium-ion battery electrodes are typically manufactured via slurry casting, which involves mixing active material particles, conductive carbon, and a polymeric binder in a solvent, followed by casting and drying the coating on current collectors (Al or Cu). These electrodes are functional but still limited in terms of pore network percolation, electronic connectivity, and mechanical stability, leading to poor electron/ion conductivities and mechanical integrity upon cycling, which result in battery degradation. To address this, we fabricate trichome-like carbon–iron fabrics via a combination of electrospinning and pyrolysis. Compared with slurry cast Fe2O3and graphite-based electrodes, the carbon–iron fabric (CMF) electrode provides enhanced high-rate capacity (10C and above) and stability, for both half cell and full cell testing (the latter with a standard lithium nickel manganese oxide (LNMO) cathode). Further, the CMFs are free-standing and lightweight; therefore, future investigation may include scaling this as an anode material for pouch cells and 18,650 cylindrical batteries.

Alternative battery technologies are required to meet growing energy demands and address the limitations of present technologies. As such, it is necessary to look beyond lithium-ion batteries. Zinc batteries enable high power density while being sourced from ubiquitous and cost-effective materials. This paper presents, for the first time known to the authors, multi-length scale tomography studies of failure mechanisms in zinc batteries with and without commercial microporous separators. In both cases, dendrites were grown, dissolved, and regrown, critically resulting in different morphology of dendritic layer formed on both the electrode and the separator. The growth of dendrites and their volume-specific areas were quantified using tomography and radiography data in unprecedented resolution. High-resolution ex situanalysis was employed to characterize single dendrites and dendritic deposits inside the separator. The findings provide unique insights into mechanisms of metal-battery failure effected by growing dendrites.

Global decarbonisation scenarios include Carbon Capture and Storage (CCS) as a key technology to reduce carbon dioxide (CO2) emissions from the power and industrial sectors. However, few large scale CCS plants are operating worldwide. This mismatch between expectations and reality is caused by a series of barriers which are preventing this technology from being adopted more widely. The goal of this paper is to identify and review the barriers to CCS development, with a focus on recent cost estimates, and to assess the potential of CCS to enable access to fossil fuels without causing dangerous levels of climate change.

In this study, we examine the degradation of nickel impregnated scandia-stabilised zirconia (ScSZ) electrode in wet hydrogen at a working temperature of SOFCs. Continuous van der Pauw measurement was carried out when the electrode was aged at 650 oC in an atmosphere with 5 vol% hydrogen and 95 vol% nitrogen. A fall in sheet conductivity was found in the electrode during ageing within 1000 min. Electrochemical impedance spectra were collected at a constant time intervals during isothermal annealing at 650 oC, 800 oC and 950 oC for the impregnated electrode, at open circuit. Three resistance contributions were decoupled by equivalent circuit fitting, i.e. the ohmic resistance, the anodic reaction resistance, and the gas diffusion resistance. Secondary electron images of electrodes before and after ageing showed an increase in nickel particle size and a decrease in the number of particles, providing microstructural evidence of coarsening. Nickel coarsening was identified as the main mechanism of degradation for the electrode in wet hydrogen.

Ni/CGO was prepared via impregnation. A facile methane pulse experiment was performed on Ni/CGO under SOFC operating condition. The outlet gas was monitored by a quadrupole mass spectrometer. A Van-Mars Krevelen type mechanism was proposed for methane reaction on Ni/CGO and analyzed in detail. The method showed promising prospect in analyzing mechanism of hydrocarbon oxidation and the results provide a new insight in the strategy of preventing carbon deposition on nickel catalyst when operating as a SOFC anode materials.

A primary challenge of gel electrolytes in development of flexible and wearable devices is their weak mechanical performances, including their compressive stress, tensile strength, and puncture resistance. Here we prepare an ionogel‐mask hybrid gel electrolyte, which successfully achieves synergic advantages of the high mechanical strength of the mask substance and the superior electrochemical and thermal characteristics of the ionogel. The fabricated supercapacitor can maintain a relatively stable capacitive performance even under a high pressure of 3236 kPa. Meanwhile, with the good thermal stability of the composite gel electrolyte, the solid‐state supercapacitor can be operated at high temperatures ranging from 25 °C to 200 °C. The ionogel‐mask hybrid gel can be superior tough gel electrolyte for solid‐state flexible supercapacitors with durable advantages in both high temperatures and pressures. The Gel in the Iono Mask: The preparation of ionogel‐in‐mask hybrid electrolytes with synergic advantages via TiO2‐initiated UV polymerization is described. The broad approach allows to prepare porous‐scaffold‐based, highly tough ionogel electrolytes with durable high pressure and thermal tolerances in supercapacitors.

In this study we present a novel method of lithium ion battery electrode sample preparation with a new type of epoxy impregnation, brominated (Br) epoxy, which is introduced here for the first time for this purpose and found suitable for focused ion beam scanning electron microscope (FIB-SEM) tomography. The Br epoxy improves image contrast, which enables higher FIB-SEM resolution (3D imaging), which is amongst the highest ever reported for composite LFP cathodes using FIB-SEM. In turn it means that the particles are well defined and the size distribution of each phase can be analyzed accurately from the complex 3D electrode microstructure using advanced quantification algorithms.The authors present for the first time a new methodology of contrast enhancement for 3D imaging, including novel advanced quantification, on a commercial Lithium Iron Phosphate (LFP) LiFePO4 cathode. The aim of this work is to improve the quality of the 3D imaging of challenging battery materials by developing methods to increase contrast between otherwise previously poorly differentiated phases. This is necessary to enable capture of the real geometry of electrode microstructures, which allows measurement of a wide range of microstructural properties such as pore/particle size distributions, surface area, tortuosity and porosity. These properties play vital roles in determining the performance of battery electrodes.

Nickel was electrodeposited on porous Ag/GDC (silver/Ce0.9Gd0.1O2-x) scaffolds and dense Ag/GDC composites for the fabrication of SOFC electrodes and catalytic membranes respectively. To control the distribution and amount of nickel deposition on the Ag/GDC surfaces; first, a systematic cyclic voltammetry study of nickel electrodeposition from a Watts bath on silver foils was carried out to understand the influence of operating conditions on the electrodeposition process. From the cyclic voltammetry study, it can be concluded that suitable operating conditions for nickel electrodeposition into porous Ag/GDC scaffolds and catalytic membranes are: 1.1 M Ni2+ concentration in Watts bath; deposition potential between [?]0.65 to [?]1.0 V vs. Ag/AgCl; a temperature at 55degC; sodium dodecyl sulfate (SDS) as the surfactant; pH 4.0 +- 0.2 and an agitation rate of 500 rpm. It was observed that the nickel surface microstructure changed with the deposition current densities due to the co-evolution of H2. Pulse and continuous electrodeposition modes allow nickel to be deposited throughout porous Ag/GDC scaffolds and onto catalytic membranes. The pulse electrodeposition mode is favored as this is shown to result in an even Ni distribution within the porous scaffolds at minimum H2 pitting.

This study investigates the stability of nickel-impregnated scandia-stabilize zirconia composite electrodes during isothermal annealing at temperatures from 600 to 950degC in a humidified hydrogen atmosphere (3 vol % water vapor). Typically an initial rapid degradation of the electrode during the first 17 h of annealing is revealed by both an increase in polarization resistance and a fall in electronic conductivity. Secondary electron images show a shift in nickel particle size toward larger values after 50 h of annealing. The declining electrochemical performance is hence attributed to nickel coarsening at elevated temperatures. Nickel coarsening has two microstructural effects: breaking up nickel percolation; and reducing the density of triple phase boundaries. Their impact on electrode area specific resistance is explored using a physical model of electrode performance which relates the macroscopic electrochemical performance to measurable microstructural parameters.

Natural gas is currently playing an increasingly significant role in low carbon development, as it provides a credible pathway to meet rising energy demand while emitting fewer greenhouse gases than from using other fossil fuels such as coal and oil. In this paper, a log linear trans-log production function model is established to investigate inter-fuel elasticity of substitution between coal, oil, natural gas and electricity in China, Japan and South Korea, respectively. In order to overcome the problem of multicollinearity, the ridge regression approach is therefore adopted to estimate the parameters of the function. Results show elasticity estimates of both coal–gas substitution and coal–electricity substitution to be positive over 1985–2012, suggesting that these two energy input pairs are substitutes at least to some extent. It also reveals that relatively higher substitution possibilities between coal and natural gas, and less opportunities to substitute coal with other fuels in China. In addition, the model results also suggest the elasticities of coal–gas substitution in China are much larger than that in Japan and South Korea, indicating there is higher possibilities of coal–gas substitution in China.

•Integrated modelling framework demonstrated for a lithium-ion battery grid storage system.•Electro–thermo–chemical phenomena captured in a dynamic and efficient simulation environment.•Battery efficiency decreases with deeper discharge for equal energy throughput.•Battery lifetime decreases with longer residence time at higher state-of-charge.•Careful selection of operating strategy can increase battery round trip efficiency and lifetime.

Tomographic techniques allow for the 3D imaging andchracterisation of complex microstructures down towards tens of nanometers; which are inadequately described in 2D. The performance of the SOFCs is dependent on nano/micro-structure as the electrochemical reactions and transport phenomena are strongly affected by the complex porous microstructure, where important reactions occur. Furthermore, during processing or operation microstructural evolution may degrade electrochemical performance. Here we use tomographic techniques to probe the 3D electrode structure at micro-nanometer length scales. Subsequently, micro/nano structural changes are followed to facilitate understanding the differences which occur with shape, structures and morphology at high resolution. Additionally the quantification of electronic, ionic and gas interfaces are also correlated with observed differences in electrode behaviour. When coupled with experiments and mechanical computational models, the results show nano/microstructural and compositional variations can significantly affect performance of SOFC electrodes. Altogether this provides important insights for electrode design and understanding sources of performance degradation.

A one-dimensional numerical model of a nickel-infiltrated gadolinium-doped ceria (Ni-GDC) electrode is developed to investigate the effect of the microstructural parameters on the electrode performance. The real electrode microstructure information is obtained with focused ion beam tomography and useful microstructural parameters such as tortuosity factor, surface information and particle/pore sizes are quantified. These are used to estimate the effective transport coefficients and the electrochemical reaction rate in the electrode. The overpotential characteristics obtained from the developed model have a quantitative agreement with the experimental results. The sensitivity analysis reveals that the performance of the examined electrode is rate-determined by the electrochemical reaction on the GDC-pore contact surface, and therefore the increase of the contact surface by decreasing the characteristic length scale down to submicron scale is effective to enhance the electrode performance.

This review discusses the range of diagnostic techniques reported in the literature for spatially resolved studies of operating fuel cells. In situdiagnostic techniques continue to reveal more about the working of fuel cells and in so doing allow for improved cell hardware design, materials selection, and choice of operating conditions to realize advanced electrochemical performance and longevity. These techniques also allow us to scrutinize the validity of conventional bulk electrical measurements and develop detailed models of fuel cell operation. This article is categorized under: Fuel Cells and Hydrogen > Science and Materials

Starting from three-dimensional X-ray tomography data of a commercial LiMn2O4 battery electrode, the effect of microstructure on the electrochemical and chemo-mechanical response of lithium-ion batteries is analyzed. Simulations show that particle size polydispersity impact the local chemical and electrical behavior of a porous electrode, while particle-particle mechanical interactions favor intercalation induced stress accumulation, resulting in a mechanically unreliable electrode microstructure. Simulations based on computer-generated electrode microstructures demonstrate that broad particle size distributions deliver up to two times higher energy density than monodisperse-sized particles based electrodes for low C-rates. However, monodisperse particle size distribution electrodes deliver the highest energy and power density for high discharge rates due to a higher surface area of reactive material per unit volume. Calculations show that the surface roughness in experimentally determined electrodes is 2.5 times higher than the one delivered by perfectly smooth spherical particles in computer generated electrodes, and provide high instantaneous power performance, but accelerate side reactions that impact negatively on power performance. The combined experimental and modeling approach demonstrates that porous electrodes with spatially uniform microstructural features improve electrochemical performance and mechanical reliability, especially for high power density applications.

Carbon formation within nickel-based solid oxide fuel cell (SOFC) anodes exposed to carbonaceous fuels typically leads to reduced operational lifetimes and performance, and can eventually lead to catastrophic failure through cracking and delamination. In-situ Raman spectroscopy has been shown to be a powerful characterization tool for the investigation of the dynamics of physical processes occurring within operational SOFCs in real time. Here we investigate the dynamics of carbon formation on a variety of nickel-based SOFC anodes as a function of temperature, fuel and electrical loading using Raman spectroscopy. We show that the rate of carbon formation throughout the SOFC anode can be significantly reduced through a careful consideration of the SOFC anode material, design and operational conditions.

Electrode tortuosity factor is a key input parameter in many fuel cell simulations. Three-dimensional microstructural data obtained from in-situ synchrotron X-ray nano-computed tomography is used as the basis for comparing five approaches to quantify the tortuosity factor. Three of these techniques are based on diffusivity simulations and showed strong correlation, but had consistently different absolute values. A random walk method showed a good degree of correlation to the diffusive approaches, but had the largest values overall. Lastly, a calculation that used a mean pore centroid approach showed little correlation to any of the other three methods, but compared well with the conventional Bruggeman correlation. Due to the diffusive nature of the ionic transport in electrodes, the authors would recommend calculating tortuosity factors using a diffusive approach based on the voxels rather than a remeshed volume.

Ni-based solid oxide fuel/electrolysis cell electrodes are often optimized for fuel cell operation without consideration of electrolysis-specific conditions. In-situ Raman spectroscopy was employed to investigate changes that occur in the surface chemistry of such electrodes during operation in electrolysis mode. Carbon deposition on Ni-gadolinium-doped ceria electrodes after CO2 electrolysis was demonstrated. Spatially resolved Raman spectroscopy has been shown to provide valuable insight into electrode optimization. Ex-situ Raman spectroscopy is used in conjunction with high resolution microscopy in order to further characterize the changes occurring within the electrodes during operation.

Understanding the chemical processes that occur at the anode triple phase boundary (TPB) between Ni, YSZ and fuel molecules is essential in determining solid oxide fuel cell (SOFC) anode performance. With a growing interest in vibrational spectroscopy for studying such processes, the surface and vibrational properties of the materials nickel (Ni) and yttria stabilized zirconia (YSZ) are investigated using first principles atomistic simulations based on density functional theory and empirical potential models. The initial findings and the methodology followed to date are presented.

Optimization of SOFC electrode or electrolyte screen-printing ink processing conditions is critical to the reliable manufacture of high quality films with optimum properties. Hence, in this study, the relationship between the ink rheology and the screen-printed film properties were investigated using nickel/scandia-stabilized-zirconia (NiO/ScSZ) anode inks having various binder (0-5 wt%) and solid contents (20-35 vol%). Ink rheological tests showed increased particle network strength in the inks with increasing binder and solids content. The electronic conductivity and electrochemical performance of anode films also increased as a function of binder and solids content. These can be related to increased particle network strength within the inks, as confirmed from the rheological studies. In conclusion, from the perspective of ink rheology, screen-printability and performance, inks having 26 vol% solid with 3 wt% binder or 28-30 vol% solid with 2 wt% binder were determined as the most suitable for the manufacturing of high quality SOFC anode films with a thickness of around 10 um.

In this study a novel electrode structure for both fuel cell and electrolysis was made by impregnation of a porous Gd-doped Ceria scaffold with Ni nano-particles. Electrical conductivity was assessed by the Van der Pauw method. Electrochemical performance in dry hydrogen was evaluated using three electrode DC and AC measurements over a range of temperatures and gas concentrations. The microstructure of the electrode was studied using Scanning Electron Microscopy. Encouraging results have been obtained for the performance of the electrode and results from these studies are reported.

Solid Oxide Fuel Cells (SOFC) are electrochemical devices where performance is dependent on reactions inside porous electrode microstructures; their complexity is inadequately described using 2D imaging. Here we use X-ray Nano-CT tomographic techniques to probe 3D electrode structures (anodes and cathodes) at micro-nanometer length scales produced using a focused ion beam. Subsequently, micro/nano structural changes in SOFC electrodes are followed and quantified to facilitate understanding changes that occur in shape, structures and morphology at high sub-100nm resolution. Time-resolved (4D) imaging revealed Ni-YSZ oxidation markedly increased above 500 oC and LSCF densification at 700 oC may close pores. Utilising 3D electrode data as geometric inputs for numerical models, revealed that increased strains were located at Ni-YSZ interfaces and at microstructure constrictions for both anodes and cathodes when heated. The results show nano/micro structural changes can affect the performance of SOFC electrodes. This combined experimental and modelling approach can help in establishing structure/performance relationships providing key insights important for transport, electrochemistry and strains in both SOFC anodes and cathodes and understanding sources of performance degradation.