Recent Advances in Heteroatom Substitution Sr2Fe1.5Mo0.5O6–δ Oxide as a more Promising Electrode Material for Symmetrical Solid-State Electrochemical Devices: A Review

Received: 02 July 2022. Accepted: 25 September 2022.In recent years, the interest in solid state electrochemical devices has significantly increased due to the various cases of their use in the energy field. The first case is the solid oxide fuel cells with both oxygen-ion and proton-conducting membranes. The second case is the electrolysis cells for hydrogen production. As a rule, in both cases, electrochemical cells consist of an ion-conducting membrane and two different electrodes. The present review is focused on structural, physicochemical, and electrochemical properties of a complex oxide based on strontium ferrite with partial replacement of iron by molybdenum. This complex oxide has a number of unique characteristics: in particular, it is able to function effectively as an electrode in oxidizing and strongly reducing atmospheres, which makes it a promising material for electrochemical devices based on solid electrolytes with symmetrical electrodes. Doping with elements in A-, B- and O-sublattices and surface modification increases electro-catalytic activity of Sr2Fe1.5Mo0.5O6−δ porous oxide material, which increases competitiveness of the electrode material for application in solid oxide electrochemical devices. Mechanisms for improving electro-catalytic activity are outlined stepwise by doping of different sublattices of double perovskite, by level of doping, and by different types of dopants. In conclusion, the data on material conductivity, power densities of both symmetric and fuel cells are systematized, and the remaining problems and prospects for future developments and upgrades of Sr2Fe1.5Mo0.5O6−δ oxide electrode material are described

Rate‐determining steps of oxygen surface exchange kinetics on Sr2Fe1.5Mo0.5O6−δ

The oxygen surface kinetics of Sr2Fe1.5Mo0.5O6−δ was determined using the 16O2/18O2 isotope exchange method with gas phase analysis at 600-800 °C. The heterogeneous exchange rates (rH) and the oxygen diffusion coefficients (D) were calculated by processing the concentration dependences of the 18O fraction using Ezin's model. The rates of oxygen dissociative adsorption (ra) and incorporation (ri) were calculated based on a model using the three exchange type rates. It has been established that the rates ra and ri were comparable in this temperature range. Assumptions were made about the effect of the chemical composition of the surface on the rate of oxygen adsorption. It was found that the oxygen exchange coefficient (k) of Sr2Fe1.5Mo0.5O6−δ is comparable to that of La0.6Sr0.4MnO3±δ oxide. High values of the oxygen diffusion coefficient were found for Sr2Fe1.5Mo0.5O6−δ. The values were comparable to those of the double cobaltite praseodymium-barium and exceed by more than an order those of lanthanum‐strontium manganite. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Russian Foundation for Basic Research, RFBR: 00161Government Council on Grants, Russian FederationThe study was partly financially supported by the Russian Foundation for Basic Research (17-08-00161) and the Russian Federation Government, agreement 02.A03.21.0006 (no. 211)

H/D Isotopic Exchange and Electrochemical Kinetics of Hydrogen Oxidation on Ni-Cermets with Oxygen-Ionic and Protonic Electrolytes

Ni–Zr0.82Y0.18O1.91 (YSZ) and Ni–La0.90Sr0.10ScO2.95 (LSS) cermets for solid oxide and protonic ceramic electrochemical cells were studied by means of H/D isotope exchange with the gas phase equilibration method for the first time. The experiments were carried out at 2 mbar of dry hydrogen in the temperature range of 400–800 ᵒC. The three parallel channels of hydrogen surface exchange were found to exist in both Ni-YSZ and Ni-LSS cermets. The mechanism of hydrogen isotope exchange for Ni-YSZ was found to be temperature independent, while, in the case of Ni-LSS, the mechanism changed with temperature and was more complicated at lower temperatures (400–600 °C). It was revealed that hydrogen spillover was the rate-determining step for both cermets. The electrochemical kinetics of hydrogen oxidation were studied on symmetric cells with a YSZ supported electrolyte and Ni-YSZ electrodes and with an LSS supported electrolyte and Ni-LSS electrodes in a wet (3 vol % H 2O) hydrogen atmosphere at 1 atm. The mechanism of hydrogen oxidation on the Ni-LSS electrode differs from that of the Ni-YSZ electrode. It changes with temperature and is also more complicated at a lower temperature range. © 2021 Elsevier B.V.This work is supported by the State Assignment of Ministry of Science and Higher Education of the Russian Federation [No. AAAA-A19-119020190078-6 ], and the Act 211 of the Government of the Russian Federation, agreement [No. 02. A03.21.0006 ]. The facilities of the Shared Access Centre “Composition of Compounds” and Unique Scientific Setup “Isotopic Exchange” of IHTE UB RAS were used. The authors are grateful D.M. Solodyankina and A.Yu. Stroeva for support in the preparation of samples

Oxygen diffusion and surface exchange kinetics for the mixed-conducting oxide La0.6Sr0.4Co0.8Fe0.2O3–δ

Received: 14.11.2018. Accepted: 11.12.2018. Published: 31.12.2018.Studies of oxygen surface exchange kinetics for La0.6Sr0.4Co0.8Fe0.2O3–δ oxide were performed using the technique of isotopic exchange of molecular oxygen with analysis of gas phase isotopic composition in a static circulation system at the temperatures of 600–800 °С in the oxygen pressure range of 0.27–2.13 kPa. The values of interphase exchange rate and oxygen diffusion coefficient were determined. The effective activation energies for oxygen exchange and diffusion processes as well as the exponents in the dependence of these values versus oxygen pressure in the double logarithmic coordinates were calculated. The process of oxygen dissociative adsorption at the surface of La0.6Sr0.4Co0.8Fe0.2O3–δ oxide was found to be the rate-determining stage.This work is partly supported by the Russian Science Foundation (Project No. 17‑73‑10196) using facilities of shared access center “Composition of Compounds” of IHTE UB RAS

Clinical and functional features and quality of life in depressive disorders in patients undergoing pulmonary thromboendarterectomy

Aim. To conduct a comparative analysis of clinical and functional parameters and quality of life (QoL) in patients with chronic thromboembolic pulmonary hypertension (CTEPH), depending on the presence of a depressive disorder in long-term postoperative period.Material and methods. The study included 182 patients with CTEPH in the long term after surgery. Depending on the Patient Health Questionnaire 9 ( PHQ-9) data, all patients were divided into 2 groups: the 1st group — patients without depressive syndrome in the long-term postoperative period, the 2nd — patients with depressive syndrome. A comparative assessment of the initial clinical and functional characteristics, as well as QoL was carried out using the SF-36 questionnaire in both groups of patients. In patients who had a coronavirus disease 2019 (COVID-19), a comparative assessment using the Post-COVID-19 Functional Status (PCFS) scale was carried out.Results. Clinically relevant depressive syndrome in patients with CTEPH in the long term after surgery was registered in 25,3% of cases. In the 2nd group of patients, prior myocardial infarction (p=0,02), concomitant chronic cerebrovascular disease (p=0,01), as well as moderate and severe post-COVID-19 functional limitations according to the PCFS scale (p=0,004) were significantly more often recorded compared with the 1st group. In the 2nd group of patients, the level of QoL in almost all parameters was significantly lower in comparison with the 1st group (p<0,05). Decreased QoL (score <40) in the 2nd group concerned numerous parameters, including the physical and mental health components. In the 1st group of patients, reduced QoL was observed only in some physical parameters.Conclusion. The group of patients with CTEPH with depressive syndrome in the long-term postoperative period was characterized by a higher incidence of concomitant chronic cerebrovascular disease and a history of myocardial infarction compared with patients without depressive disorders. In the group of patients with depressive disorders, moderate and severe post-COVID-19 functional limitations according to the PCFS scale were more often observed. Depressive disorders in patients with CTEPH in the long-term postoperative period were accompanied by significantly reduced QoL parameters. Patients experienced the greatest difficulties both during normal daily activities and in professional activities

Влияние нейровегетативной защиты мозга на основные показатели системной гемодинамики и течение острейшего периода инсульта

For the study of effect neurovegetative blockade of the brain on the course of an stroke in the acute period was carried out noninvasion monitoring of the basic parameters systems haemodinamic and a vegetative homeostasis with use of Kerdo Index at 110 patients with different types of stroke. The neurovegetative blockade having been started in the first day of the brain damage promotes the decrease of damaging reactions manifestations, normalization of vegetative homeostasis and promonting more favourable course of acute period stroke and its prognosis.С целью определения влияния нейровегетативной защиты мозга на течение острейшего периода инсульта проведен неинвазивный мониторинг основных показателей системной гемодинамики и вегетативного тонуса с использованием индекса Кердо у 110 больных с различными типами инсульта на нейрореанимационном этапе. Нейровегетативная блокада, начатая с 1-х сут инсульта, способствует снижению выраженности повреждающих реакций, стабилизации гемодинамики, нормализации вегетативного тонуса и благоприятному течению и исходу острейшего периода инсульта

Oxygen tracer diffusion and surface exchange kinetics in Ba0.5Sr0.5Co0.8Fe0.2O3 - δ

The oxygen tracer diffusion coefficient, Db∗, and the oxygen tracer surface exchange coefficient, k, were measured in Ba0.5Sr0.5Co0.8Fe0.2O3 - δ (BSCF5582) over the temperature range of 310-800 °C and the oxygen partial pressure range of 1.3 × 10- 3-0.21 bar. Several measurement techniques were used: isotope exchange followed by depth profiling (IEDP) within individual single grains or line scanning (IELS) along the sample cross-section and gas-phase analysis (GPA). Surface exchange kinetics was initially found to be slow and presumably inhibited by the formation of a passivating layer on the sample surface. High temperature pre-anneals (900-950 °C) changed the nature of this layer and enhanced surface exchange. Fast bulk oxygen diffusion and surface exchange kinetics were observed after high temperature pre-anneals within the temperature range studied. The activation energies for 18O tracer diffusion and surface exchange at 0.21 bar were 0.72 ± 0.05 and 1.10 ± 0.15 eV, respectively. The tracer diffusion coefficient showed weak dependence upon oxygen partial pressure, whereas the surface exchange coefficient exhibited strong oxygen partial pressure dependence. The microstructure of the samples (the porosity and grain size) had a profound effect on the measured tracer diffusion coefficient. © 2014 Elsevier B.V

Effect of Lithium Borate Coating on the Electrochemical Properties of LiCoO2 Electrode for Lithium-Ion Batteries

Received: 13.10.2020. Revised: 18.11.2020. Accepted: 26.11.2020. Available online: 21.12.2020.This article belongs to the regular issue.The effect of a protective coating of fused lithium borate, Li3BO3, on the physicochemical and electrochemical characteristics of LiCoO2 has been studied. A cathode material produced by the SCS method using binary organic fuel, glycine and citric acid. The influence of the experiment conditions on the morphology, crystal structure and specific surface of lithium cobaltite was studied. Electrochemical testing of LiCoO2∙nLi3BO3 samples, n = 5 and 7 mass %, has been performed in the cathode Li|Li+-electrolyte|LiCoO2∙nLi3BO3 half-cell using 1M LiPF6 in EC/DMC mixture (1:1) as electrolyte in the 2.7-4.3 V range at normalized discharge current С/10, С/5, С/2. The maximal initial discharge capacity of 185 mAh/g was detected for the samples with 5 mass % Li3BO3. The coulomb efficiency of optimal materials in the 40th cycle was 99.1%.The work was performed in accordance with the state as-signments of the Institute of Chemistry of Solids of the Ural Branch of the RAS, No. AAAA-A19-119031890026-6 and No. АААА-А19-119102990044-6, the state assignment of the Institute of Problems of Chemical Physics of the RAS, No. АААА-А19-119061890019-5, and Thematic map No. 0089-2019-0007 «Functional materials for chemical power sources»

Хроническая обструктивная болезнь легких и результаты реваскуляризации миокарда: взаимосвязь с качеством жизни

Aim. To assess the impact of chronic obstructive pulmonary disease (COPD) on the outcomes of myocardial revascularisation and the self-reported quality of life (QoL) during long-term follow-up. Methods. This prospective cohort study included 454 consecutive patients who underwent scheduled myocardial revascularisation. The follow-up continued for 3 years after the surgery. All patients underwent pulmonary functional tests before the surgery. The diagnosis of COPD was verified according to the Global Initiative for Obstructive Lung Disease criteria. QoL assessment was performed before and 3 years after the surgery using the 36-Item Short-Form Health Survey (SF-36). Results. In the study group, the diagnosis of COPD was verified in 14.5% of cases. The mortality rate was 5%, and was significantly higher in patients with COPD. The baseline QoL level was reduced in all patients, regardless of the presence of COPD, with an average of 50 points both in the physical and mental health scores of the SF-36 questionnaire. COPD had a significant negative impact on the QoL physical health score after myocardial revascularisation (odds ratio (OR) 0.95 (0.91 - 0.99), p = 0.043). The forced expiratory volume in the first second (OR 1.02 (1.00 - 1.07), p = 0.048) and new-onset atrial fibrillation in the early postoperative period (OR 0.54 (0.33 - 0.88), p = 0,036) were predictors of lack of QoL improvement. COPD did not correlate with the changes in the psychoemotional component of QoL. Conclusion. COPD has an independent negative impact on the clinical outcomes of myocardial revascularisation, including survival and health-related QoL (physical health score). Thereby, preoperative assessment of the respiratory function is important in these patients.Целью исследования явилась оценка влияния хронической обструктивной болезни легких (ХОБЛ) на результаты реваскуляризации миокарда (РМ) и качество жизни (КЖ) пациентов в долгосрочном периоде наблюдения. Материалы и методы. В проспективное когортное исследование включены пациенты (n = 454) с ишемической болезнью сердца, госпитализированные для проведения плановой РМ. Период наблюдения составил 3 года после вмешательства. До хирургического лечения у пациентов проводились легочные функциональные тесты. Диагноз ХОБЛ верифицирован в соответствии с критериями Глобальной инициативы диагностики лечения и профилактики ХОБЛ (Global Initiative for Chronic Obstructive Lung Disease (GOLD)). Оценка КЖ проводилась до и через 3 года после хирургического вмешательства по данным опросника SF-36. Результаты. Диагноз ХОБЛ верифицирован в 14,5 % случаев. Смертность при 3-летнем наблюдении после РМ составила 5 % со значительным преобладанием среди пациентов с ХОБЛ. Независимо от наличия ХОБЛ, исходно сниженный уровень КЖ отмечен у всех кардиохирургических пациентов по шкале SF-36 (физический и психоэмоциональный компоненты КЖ). Установлено значимое негативное влияние ХОБЛ на динамику КЖ после РМ по шкале физического компонента КЖ (отношение шансов (ОШ) — 0,95 (0,91—0,99); р = 0,043). Предикторами отсутствия положительной динамики КЖ также явились такие показатели, как объем форсированного выдоха за 1-ю секунду (ОШ — 1,02 (1,00—1,07); р = 0,048) и впервые возникшая в раннем послеоперационном периоде фибрилляция предсердий (ОШ - 0,54 (0,33-0,88); р = 0,036). В данном исследовании не показано значимой связи ХОБЛ с динамикой психоэмоционального компонента КЖ. Заключение. У пациентов, перенесших РМ, ХОБЛ оказывает независимое негативное влияние на клинический исход, включая выживаемость и КЖ (физический компонент здоровья), при этом подчеркивается важность предоперационной оценки функции внешнего дыхания у пациентов кардиохирургического профиля