Stability of Ni-Fe-Layered Double Hydroxide Under Long-Term Operation in AEM Water Electrolysis.

Anion exchange membrane water electrolysis (AEMWE) is an attractive method for green hydrogen production. It allows the use of non-platinum group metal catalysts and can achieve performance comparable to proton exchange membrane water electrolyzers due to recent technological advances. While current systems already show high performances with available materials, research gaps remain in understanding electrode durability and degradation behavior. In this study, the performance and degradation tracking of a Ni3Fe-LDH-based single-cell is implemented and investigated through the correlation of electrochemical data using chemical and physical characterization methods. A performance stability of 1000 h, with a degradation rate of 84 µV h-1 at 1 A cm-2 is achieved, presenting the Ni3Fe-LDH-based cell as a stable and cost-attractive AEMWE system. The results show that the conductivity of the formed Ni-Fe-phase is one key to obtaining high electrolyzer performance and that, despite Fe leaching, change in anion-conducting binder compound, and morphological changes inside the catalyst bulk, the Ni3Fe-LDH-based single-cells demonstrate high performance and durability. The work reveals the importance of longer stability tests and presents a holistic approach of electrochemical tracking and post-mortem analysis that offers a guideline for investigating electrode degradation behavior over extended measurement periods.

Lung damage in SARS-CoV-2 patients: An autopsy study in the era of vaccination.

AIMS: The contribution of SARS-CoV-2 infection on lung damage and the effect of vaccination on either containing the number of deaths or mitigating lung damage has not been systematically investigated. METHODS: Post-mortem analysis was performed among consecutive in-patients with COVID-19 deceased in the Province of Trieste (2020-2022). The outcomes of the study were (i) rates of in-hospital mortality, (ii) contribution of COVID-19 to death, (iii) histological extent of lung injury and (iv) impact of vaccination. RESULTS: A total of 1038 consecutive hospitalized patients who died with SARS-CoV-2 infection were autopsied and deep histological analysis of the lungs was performed in a randomly selected sample of 508 cases. Among them, SARS-CoV-2 infection was (a) the cause of death (n = 90), (b) contributing to death (n = 304) and (c) an accompanying feature (n = 114). The incidence of SARS-CoV-2 infection as the primary cause of mortality decreased over time (23.8% in 2020, 20.9% in 2021 and 7.9% in 2022). On multivariable analysis, vaccination (any dose) was independently associated with lower rates of death related to SARS-CoV-2 infection (HR .15, p < .001), after adjusting for other independent predictors. A total of 172 patients were vaccinated at least with two doses at the time of death: 93% triple-vaccinated, 7% double-vaccinated. On histological analysis, vaccinated patients had a greater frequency of pneumonia severity score 0 and 1 (20.3% vs. 5.4% and 20.9% vs. 7.7%, p < .001, respectively), and a substantially lower proportion of pneumonia severity score 3 (26.2% vs. 55.1%, p < .001) compared to unvaccinated patients. CONCLUSIONS: COVID-19 vaccination has substantially reduced rates of death related to SARS-CoV-2 infection over time and may have the ability to mitigate lung damage.

Persistent SARS-CoV-2 infection in patients seemingly recovered from COVID-19.

SARS-CoV-2 infection is clinically heterogeneous, ranging from asymptomatic to deadly. A few patients with COVID-19 appear to recover from acute viral infection but nevertheless progress in their disease and eventually die, despite persistent negativity at molecular tests for SARS-CoV-2 RNA. Here, we performed post-mortem analyses in 27 consecutive patients who had apparently recovered from COVID-19 but had progressively worsened in their clinical conditions despite repeated viral negativity in nasopharyngeal swabs or bronchioalveolar lavage for 11-300 consecutive days (average: 105.5 days). Three of these patients remained PCR-negative for over 9 months. Post-mortem analysis revealed evidence of diffuse or focal interstitial pneumonia in 23/27 (81%) patients, accompanied by extensive fibrotic substitution in 13 cases (47%). Despite apparent virological remission, lung pathology was similar to that observed in acute COVID-19 individuals, including micro- and macro-vascular thrombosis (67% of cases), vasculitis (24%), squamous metaplasia of the respiratory epithelium (30%), frequent cytological abnormalities and syncytia (67%), and the presence of dysmorphic features in the bronchial cartilage (44%). Consistent with molecular test negativity, SARS-CoV-2 antigens were not detected in the respiratory epithelium. In contrast, antibodies against both spike and nucleocapsid revealed the frequent (70%) infection of bronchial cartilage chondrocytes and para-bronchial gland epithelial cells. In a few patients (19%), we also detected positivity in vascular pericytes and endothelial cells. Quantitative RT-PCR amplification in tissue lysates confirmed the presence of viral RNA. Together, these findings indicate that SARS-CoV-2 infection can persist significantly longer than suggested by standard PCR-negative tests, with specific infection of specific cell types in the lung. Whether these persistently infected cells also play a pathogenic role in long COVID remains to be addressed. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Morphological and Genetic Aspects for Post-Mortem Diagnosis of Hypertrophic Cardiomyopathy: A Systematic Review.

Hypertrophic cardiomyopathy (HCM) is one of the most common genetic cardiovascular diseases, and it shows an autosomal dominant pattern of inheritance. HCM can be clinically silent, and sudden unexpected death due to malignant arrhythmias may be the first manifestation. Thus, the HCM diagnosis could be performed at a clinical and judicial autopsy and offer useful findings on morphological features; moreover, it could integrate the knowledge on the genetic aspect of the disease. This review aims to systematically analyze the literature on the main post-mortem investigations and the related findings of HCM to reach a well-characterized and stringent diagnosis; the review was performed using PubMed and Scopus databases. The articles on the post-mortem evaluation of HCM by gross and microscopic evaluation, imaging, and genetic test were selected; a total of 36 studies were included. HCM was described with a wide range of gross findings, and there were cases without morphological alterations. Myocyte hypertrophy, disarray, fibrosis, and small vessel disease were the main histological findings. The post-mortem genetic tests allowed the diagnosis to be reached in cases without morpho-structural abnormalities; clinical and forensic pathologists have a pivotal role in HCM diagnosis; they contribute to a better definition of the disease and also provide data on the genotype-phenotype correlation, which is useful for clinical research.

Arrhythmogenic Right Ventricular Cardiomyopathy Post-Mortem Assessment: A Systematic Review.

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder characterized by the progressive fibro-fatty replacement of the right ventricular myocardium, leading to myocardial atrophy. Although the structural changes usually affect the right ventricle, the pathology may also manifest with either isolated left ventricular myocardium or biventricular involvement. As ARVC shows an autosomal dominant pattern of inheritance with variable penetrance, the clinical presentation of the disease is highly heterogeneous, with different degrees of severity and patterns of myocardial involvement even in patients of the same familiar group with the same gene mutation: the pathology spectrum ranges from the absence of symptoms to sudden cardiac death (SCD) sustained by ventricular arrhythmias, which may, in some cases, be the first manifestation of an otherwise silent pathology. An evidence-based systematic review of the literature was conducted to evaluate the state of the art of the diagnostic techniques for the correct post-mortem identification of ARVC. The research was performed using the electronic databases PubMed and Scopus. A methodological approach to reach a correct post-mortem diagnosis of ARVC was described, analyzing the main post-mortem peculiar macroscopic, microscopic and radiological alterations. In addition, the importance of performing post-mortem genetic tests has been underlined, which may lead to the correct identification and characterization of the disease, especially in those ARVC forms where anatomopathological investigation does not show evident morphostructural damage. Furthermore, the usefulness of genetic testing is not exclusively limited to the correct diagnosis of the pathology, but is essential for promoting targeted screening programs to the deceased's family members. Nowadays, the post-mortem diagnosis of ARVC performed by forensic pathologist remains very challenging: therefore, the identification of a clear methodological approach may lead to both a reduction in under-diagnoses and to the improvement of knowledge on the disease.

Forensic Biochemical Markers to Evaluate the Agonal Period: A Literature Review.

Currently, forensic research is multidisciplinary with new methods and parameters useful to define the cause and time of death as well as survival/agony times. The identification of biochemical markers able to estimate agonal period has been studied by many forensic researchers. It is known that the estimation of agonal time in different types of death is not always easy, hence our interest in literature's data. The studies analyzed in this review confirm the important role of thanatobiochemistry for the estimation of survival times. Regardless of the death cause, the survival/agony time between the primary event and death influences markers concentrations in biological samples (e.g., blood, urine, cerebrospinal fluid). Different biomarkers can be used for qualitative evaluations in deaths with short and long agony (e.g., C-reactive protein, ferritin, GFAP, etc.). Instead, the quantitative interpretation showed limits due to the lack of reference cut-offs. Thanatobiochemistry is a useful tool to confirm what emerged from autopsies findings (macroscopic and histological analysis), but further studies are desirable to confirm the evidence emerging from our review of the literature.

Ethanol Determination in Post-Mortem Samples: Correlation between Blood and Vitreous Humor Concentration.

Ethanol (ethylic alcohol) represents the most commonly used drug worldwide and is often involved in clinical and forensic toxicology. Based on several reports, excessive alcohol consumption is the main contributing factor in traffic accidents, drownings, suicides, and other crimes. For these reasons, it becomes essential to analyze the alcohol concentration during autopsy. Although blood is usually used for alcohol analysis in post-mortem cases, it could suffer alterations, putrefaction, and microbial contaminations. As an alternative to whole blood, vitreous humor has been successfully used in medico-legal studies. In this work, post-mortem specimens were analyzed for ethanol determination. The analysis of blood and vitreous humor were carried-out using gas chromatography-flame ionized detector (GC-FID) with a total run time of 6 min. The method was validated in terms of limit of detection, limit of quantification, dynamic range, sensibility, recovery, precision and trueness. A linear regression analysis indicated a coefficient of determination (R2) of 0.9981. The study confirmed no statistically differences between alcohol concentration in blood and vitreous humor, leading vitreous humor as an excellent matrix that could be used as an alternative to whole blood in toxicological analysis in cases where blood is not available.

Post-Mortem Immunohistochemical Evidence of ß2-Adrenergic Receptor Expression in the Adrenal Gland.

The evidence from post-mortem biochemical studies conducted on cortisol and catecholamines suggest that analysis of the adrenal gland could provide useful information about its role in human pathophysiology and the stress response. Authors designed an immunohistochemical study on the expression of the adrenal ß2-adrenergic receptor (ß2-AR), a receptor with high-affinity for catecholamines, with the aim to show which zones it is expressed in and how its expression differs in relation to the cause of death. The immunohistochemical study was performed on adrenal glands obtained from 48 forensic autopsies of subjects that died as a result of different pathogenic mechanisms using a mouse monoclonal ß2-AR antibody. The results show that immunoreactivity for ß2-AR was observed in all adrenal zones. Furthermore, immunoreactivity for ß2-AR has shown variation in the localization and intensity of different patterns in relation to the original cause of death. To the best of our knowledge, this is the first study that demonstrates ß2-AR expression in the human cortex and provides suggestions on the possible involvement of ß2-AR in human cortex hormonal stimulation. In conclusion, the authors provide a possible explanation for the observed differences in expression in relation to the cause of death.

Brain alterations with deep brain stimulation: New insight from a neuropathological case series.

BACKGROUND: Previous studies on human brain tissue alterations caused by deep brain stimulation described glial and reactive inflammatory changes. In the current pathoanatomical study, we extended the analysis to signs of axonal changes and the influence of concomitant disease. METHODS: Brains of 10 patients with Parkinson's disease or essential tremor and a total of 18 electrodes were systematically examined up to 7.5 y after surgery. RESULTS: In general, tissue that had long-term contact with the electrode material exhibited astrogliosis in all, T-lymphocytes in 93%, and multinucleated giant cells in 68% of patients. Immunohistochemistry showed an increase in amyloid precursor protein immunoreactive axonal swellings in the brain at the electrically active parts of the electrodes. Patients who died of septicemia showed a more severe astrogliosis and giant cell reaction than patients who died of cardiovascular events. Parkinson's disease or essential tremor did not differentially produce histopathological changes around the electrodes. CONCLUSION: Long-term electrical stimulation by deep brain stimulation causes minor axonal changes. The cause of death, but not the underlying neurological disease, affects the histopathological changes around the electrode. The findings need to be reproduced by examining larger patient subgroups.

Analyzing the Effect of Electrolyte Quantity on the Aging of Lithium-Ion Batteries.

Despite a substantial impact on various economic and cell technology factors, the influence of electrolyte quantities is rarely addressed in research. This study examines the impact of varying electrolyte quantities on cell performance and aging processes using three different electrolytes: LP57 (1 M LiPF6 in ethylene carbonate:ethyl methyl carbonate (EC:EMC 3:7 w/w), LP572 (LP57+2 wt.% vinylene carbonate (VC)) and LP57 + absVC (18.351 mg VC). Comprehensive analytical post mortem investigations revealed that continuous excessive electrolyte decomposition determines the performance of cells using LP57, leading to enhanced irreversible lithium-ion loss and interphase thickening with increasing electrolyte volume. Impedance rise due to the growth of the interphase was also identified as the cause of degrading cell performance with rising amounts of LP572, attributed to an increasingly pronounced consumption of VC rather than electrolyte aging effects. By varying the electrolyte quantity while maintaining a constant amount VC within the cell system, the differences in cell performance were minimized, and observed deteriorating effects were suppressed. This study demonstrates the sensitive interdependence of electrolyte volume and additive concentration, practically affecting aging behavior. Comprehensively understanding the characteristics of each individual electrolyte component and tailoring the electrolytes to cell-specific cell properties proves to be crucial to optimize cell performance.

Lift-Out Specimen Preparation and Multiscale Correlative Investigation of Li-Ion Battery Electrodes Using Focused Ion Beam-Secondary Ion Mass Spectrometry Platforms.

Advanced characterization is paramount to understanding battery cycling and degradation in greater detail. Herein, we present a novel methodology of battery electrode analysis, employing focused ion beam (FIB) secondary-ion mass spectrometry platforms coupled with a specific lift-out specimen preparation, allowing us to optimize analysis and prevent air contamination. Correlative microscopy, combining electron microscopy and chemical imaging of a liquid electrolyte Li-ion battery electrode, is performed over the entire electrode thickness down to subparticle domains. We observed a distinctive remnant lithiation among interparticles of the anode at the discharge state. Furthermore, chemical mapping reveals the nanometric architecture of advanced composite active materials with a lateral resolution of 16 nm and the presence of a solid electrolyte interface on the particle boundaries. We highlight the methodological advantages of studying interfaces and the ability to conduct high-performance chemical and morphological correlative analyses of battery materials and comment on their potential use in other fields.

Mechanical Activation of Graphite for Na-Ion Battery Anodes: Unexpected Reversible Reaction on Solid Electrolyte Interphase via X-Ray Analysis.

Although sodium-ion batteries (SIBs) offer promising low-cost alternatives to lithium-ion batteries (LIBs), several challenges need to be overcome for their widespread adoption. A primary concern is the optimization of carbon anodes. Graphite, vital to the commercial viability of LIBs, has a limited capacity for sodium ions. Numerous alternatives to graphite are explored, particularly focusing on disordered carbons, including hard carbon. However, compared with graphite, most of these materials underperform in LIBs. Furthermore, the reaction mechanism between carbon and sodium ions remains ambiguous owing to the structural diversity of disordered carbon. A straightforward mechanical approach is introduced to enhance the sodium ion storage capacity of graphite, supported by comprehensive analytical techniques. Mechanically activated graphite delivers a notable reversible capacity of 290.5 mAh·g-1 at a current density of 10 mA·g-1. Moreover, it maintains a capacity of 157.7 mAh·g-1 even at a current density of 1 A·g-1, benefiting from the defect-rich structure achieved by mechanical activation. Soft X-ray analysis revealed that this defect-rich carbon employs a sodium-ion storage mechanism distinct from that of hard carbon. This leads to an unexpected reversible reaction on the solid electrolyte surface. These insights pave the way for innovative design approaches for carbon electrodes in SIB anodes.

Post mortem chiral analysis of MDMA and MDA in human blood and hair.

Drug-related fatalities in the EU are predominantly associated with opioids. MDMA (Ecstasy) consumption results in fewer lethal intoxications despite its widespread use. This study investigates MDMA-related fatalities, focusing on enantiomer ratios of MDMA and its metabolite MDA to explore the role of metabolism in fatal outcomes. MDMA induces euphoria, increased empathy, and physiological effects such as tachycardia, hypertension, and hyperthermia. Metabolism mainly involves CYP1A2 and CYP2D6, with polymorphism of the latter influencing metabolism rates. Our institute observed several MDMA-related fatalities, which prompted an investigation into the potential role of inefficient drug metabolism in these cases. A novel quantitative chiral analysis method was developed and validated for MDMA, MDA, amphetamine and methamphetamine enantiomers in human blood. Analysis of post mortem blood samples from eleven MDMA-related fatalities exhibited a wide range of concentrations and enantiomer ratios. Variability in R/S MDMA ratios, however, could be linked to the time period of metabolism. Hair analysis revealed high MDMA concentrations in all segments, irrespective of prior drug abuse anamnesis. Therefore, hair analysis may not be suitable for the assessment of past drug use in ecstasy-related fatalities. The results indicated that elevated levels of the MDMA enantiomer are correlated with longer survival times in cases of intoxication. However, there was no clear evidence for slowed MDMA metabolism as a cause of lethal intoxications. While challenges remain due to the diversity of cases, this study contributes valuable insights into ecstasy intoxications, aiding future interpretation of post mortem analysis.

Toxicologic analysis of 35 drugs in post mortem human blood samples with focus on antihypertensive and antiarrhythmic drugs.

Antiarrhythmic and antihypertensive drugs are frequently encountered in post mortem analysis, and the question may arise as to whether they were administered in therapeutic doses, and if they were taken in accidental, intentional, or suicidal overdose scenarios. Therefore, a novel analytical method was developed and validated for the quantification of 35 drugs with toxicological relevance, including antihypertensive and antiarrhythmic drugs (ajmaline, amlodipine, amiodarone, atenolol, bisoprolol, carvedilol, clonidine, desethylamiodarone, diltiazem, donepezil, doxazosin, dronedarone, esmolol, flecainide, lercanidipine, lidocaine, metoprolol, nebivolol, nimodipine, pindolol, prajmaline, propafenone, propranolol, sotalol, urapidil, and verapamil), as well as other medications commonly found in combination (sildenafil, tadalafil, atorvastatin, clopidogrel, dapoxetine, memantine, pentoxifylline, rivastigmine, and ivabradine). The method enables simultaneous identification and quantification in blood samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Validation exhibited excellent linearity across the concentration range for all analytes. Precision and accuracy were within acceptable limits, with bias and relative standard deviation (RSD) values consistently below 9 % and 10 %, respectively. Selectivity and specificity assessments confirmed the absence of any interference from contaminants or co-extracted drugs. The method demonstrated very high sensitivity, with limits of detection (LOD) as low as 0.01 ng/ml and limits of quantification (LOQ) as low as 0.04 ng/ml. Extraction recovery exceeded 57.5 % for all analytes except atenolol, and matrix effects were <17 % for all analytes except pindolol. Processed sample stability evaluations revealed consistent results with acceptable deviations for all analytes. In addition, the method was specifically tested for the use in post mortem analysis. The applicability of our method was demonstrated by the analysis of two authentic human autopsy blood samples.

γ-Valerolactone as Sustainable and Low-Toxic Solvent for Electrical Double Layer Capacitors.

In this work, γ-valerolactone (GVL), a green solvent based on largely available biomass (carbohydrates), highly biodegradable, and with low eco-toxicological profile, was used as electrolyte component in energy storage devices. This solvent allowed the realization of electrolytes with good transport properties and high thermal stability, which could be successfully applied in electrical double layer capacitors (EDLCs). GVL-based EDLCs could operate at 2.7-2.9 V and displayed good performance in term of capacitance, cycling stability, as well as specific energy and power. The results of this study indicate that the use of solvent obtained from largely available natural sources is a feasible strategy for the realization of sustainable and safe electrolytes for EDLCs.

11-Nor-9-Carboxy Tetrahydrocannabinol Distribution in Fluid from the Chest Cavity in Cannabis-Related Post-Mortem Cases.

In this study, the presence of 11-nor-Δ9-carboxy tetrahydrocannabinol (THC-COOH) in postmortem fluid obtained from the chest cavity (FCC) of postmortem cases collected from drug-related fatalities or criminal-related deaths in Jeddah, Saudi Arabia, was investigated to evaluate its suitability for use as a complementary specimen to blood and biological specimens in cases where no bodily fluids are available or suitable for analysis. The relationships between THC-COOH concentrations in the FCC samples and age, body mass index (BMI), polydrug intoxication, manner, and cause of death were investigated. METHODS: Fifteen postmortem cases of FCC were analyzed using fully validated liquid chromatography-positive-electrospray ionization tandem mass spectrometry (LC-MS/MS). RESULTS: FCC samples were collected from 15 postmortem cases; only THC-COOH tested positive, with a median concentration of 480 ng/mL (range = 80-3010 ng/mL). THC-COOH in FCC were higher than THC-COOH in all tested specimens with exception to bile, the median ratio FCC/blood with sodium fluoride, FCC/urine, FCC/gastric content, FCC/bile, FCC/liver, FCC/kidney, FCC/brain, FCC/stomach wall, FCC/lung, and FCC/intestine tissue were 48, 2, 0.2, 6, 4, 6, 102, 11, 5 and 10-fold, respectively. CONCLUSION: This is the first postmortem report of THC-COOH in the FCC using cannabinoid-related analysis. The FCC samples were liquid, easy to manipulate, and extracted using the same procedure as the blood samples. The source of THC-COOH detected in FCC could be derived from the surrounding organs due to postmortem redistribution or contamination due to postmortem changes after death. THC-COOH, which is stored in adipose tissues, could be a major source of THC-COOH found in the FCC.

Dystrophin and metalloproteinase 9 in myocardial ischemia: A post-mortem immunohistochemical study.

The presented study evaluated the expression of dystrophin and MMP-9 in cases of sudden cardiac death (SCD) due to coronary atherosclerotic disease (CAD) in order to analyze the characteristics and the chronology of their expression, providing evidence on the possible role in post-mortem diagnosis of myocardial ischemia. The expression of these proteins was also compared to C5b-9 complex and fibronectin expression to evaluate any differences. Two groups of CAD-related SCD, respectively group 1 with gross and/or histological evidence and group 2 with no specific histological signs of myocardial ischemia, were used. A third group formed by cases of acute mechanical asphyxiation was used as a control. The immunohistochemical staining by dystrophin, MMP-9, C5b-9, and fibronectin antibodies was performed. The study revealed that dystrophin and MMP-9 showed different expression in group 1 and group 2 as, respectively, different degree of sarcolemmal staining depletion and increasing of interstitial and granulocytes immunopositivity. Moreover, loss of dystrophin staining and C5b-9 immunopositivity were more significant when compared to MMP-9 increasing. Dystrophin and MMP-9 seemed to be useful immunohistochemical markers for the detection of myocardial ischemic damage. However, the comparison of the four markers suggested that loss of dystrophin could be considered as an earlier marker.

Comprehensive Investigation of a Slight Overcharge on Degradation and Thermal Runaway Behavior of Lithium-Ion Batteries.

Overcharge is a hazardous abuse condition that has dominant influences on cell performance and safety. This work, for the first time, comprehensively investigates the impact of different overcharge degrees on degradation and thermal runaway behavior of lithium-ion batteries. The results indicate that single overcharge has little influence on cell capacity, while it severely degrades thermal stability. Degradation mechanisms are investigated by utilizing the incremental capacity-differential voltage and relaxation voltage analyses. During the slight overcharge process, the conductivity loss and the loss of lithium inventory always occur; the loss of active material starts happening only when the cell is overcharged to a certain degree. Lithium plating is the major cause for the loss of lithium inventory, and an interesting phenomenon that the arrival time of the dV/dt peak decreases linearly with the increase of the overcharge degree is found. The cells with different degrees of overcharge exhibit a similar behavior during adiabatic thermal runaway. Meanwhile, the relationship between sudden voltage drop and thermal runaway is further established. More importantly, the characteristic temperature of thermal runaway, especially the self-heating temperature (T1), decreases severely along with overcharging, which means that a slight overcharge severely decreases the cell thermal stability. Further, post-mortem analysis is conducted to investigate the degradation mechanisms. The mechanism of the side reactions caused by a slight overcharge on the degradation performance and thermal runaway characteristics is revealed.

Degradation Mechanisms of Solid Oxide Fuel Cells under Various Thermal Cycling Conditions.

A critical issue to tackle before successful commercialization of solid oxide fuel cells (SOFCs) can be achieved is the long-term thermal stability required for SOFCs to operate reliably without significant performance degradation despite enduring thermal cycling. In this work, the impact of thermal cycling on the durability of NiO-yttria-stabilized zirconia-based anode-supported cells is studied using three different heating/cooling rates (1, 2, and 5 °C min-1) as the temperature fluctuated between 400 and 700 °C. Our experiments simulate time periods when power from SOFCs is not required (e.g., as might occur at night or during an emergency shutdown). The decay ratios of the cell voltages are 8.8% (82 µV h-1) and 19.1% (187 µV h-1) after thermal cycling testing at heating/cooling rates of 1 and 5 °C min-1, respectively, over a period of 1000 h. The results indicate SOFCs that undergo rapid thermal cycling experience much greater performance degradation than cells that experience slow heating/cooling rates. The changes in total resistance for thermally cycled cells are determined by measuring the Rpol of the electrodes (whereas the ohmic resistances of the cells remain unchanged from their initial value), signifying that electrode deterioration is the main degradation mechanism for SOFCs under thermal cycling. In particular, fast thermal cycling leads to severe degradation in the anode part of SOFCs with substantial agglomeration and depletion of Ni particles seen in our characterizations with field emission-scanning electron microscopy and electron probe microanalysis. In addition, the mean particle size in the cathode after thermal cycling testing increases from 0.104 to 0.201 µm for the 5 °C min-1 cell. Further, the presence of Sr-enriched regions is more significant in the La0.6Sr0.4Co0.2Fe0.8O3-δ cathode after fast thermally cycled SOFCs.

Improved Sodiation Additive and Its Nuances in the Performance Enhancement of Sodium-Ion Batteries.

The abundance of the available sodium sources has led to rapid progress in sodium-ion batteries (SIBs), making them potential candidates for immediate replacement of lithium-ion batteries (LIBs). However, commercialization of SIBs has been hampered by their fading efficiency due to the sodium consumed in the formation of solid-electrolyte interphase (SEI) when using hard carbon (HC) anodes. Herein, Na2C3O5 sodium salt is introduced as a highly efficient, cost-effective, and safe cathode sodiation additive. This sustainable sodium salt has an oxidation potential of ∼4.0 V vs Na+/Na°, so it could be practically implemented into SIBs. Moreover, for the first time, we have also revealed by X-ray photoelectron spectroscopy (XPS) that in addition to the compensating Na+ ions spent in the SEI layer, the high specific capacity and capacity retention observed from electrochemical measurements are due to the formation of a thinner and more stable cathode-electrolyte interphase (CEI) on the P2-Na2/3Mn0.8Fe0.1Ti0.1O2 while using such a cathode sodiation additive. Half-cell studies with P2-Na2/3Mn0.8Fe0.1Ti0.1O2 cathodes show a 27% increase in the specific capacity (164 mAh gP2-1) with cathode sodiation additives. Full-cell studies with the HC anode show a 4 times increase in the specific capacity of P2-Na2/3Mn0.8Fe0.1Ti0.1O2. This work provides notable insights into and avenues toward the development of SIBs.