Defect-Driven Anomalous Transport in Fast-Ion Conducting Solid Electrolytes

Solid-state ionic conduction is a key enabler of electrochemical energy storage and conversion. The mechanistic connections between material processing, defect chemistry, transport dynamics, and practical performance are of considerable importance, but remain incomplete. Here, inspired by studies of fluids and biophysical systems, we re-examine anomalous diffusion in the iconic two-dimensional fast-ion conductors, the $\beta$- and $\beta^{\prime\prime}$-aluminas. Using large-scale simulations, we reproduce the frequency dependence of alternating-current ionic conductivity data. We show how the distribution of charge-compensating defects, modulated by processing, drives static and dynamic disorder, which lead to persistent sub-diffusive ion transport at macroscopic timescales. We deconvolute the effects of repulsions between mobile ions, the attraction between the mobile ions and charge-compensating defects, and geometric crowding on ionic conductivity. Our quantitative framework based on these model solid electrolytes connects their atomistic defect chemistry to macroscopic performance with minimal assumptions and enables mechanism-driven 'atoms-to-device' optimization of fast-ion conductors.Comment: 45 pages, 23 figures. Additional code is available at https://github.com/apoletayev/anomalous_ion_conductio

Determination of microrelief of the sample by singular beams superposition

In present paper we propose easy way to implement method of interfering vortices with opposite topological charge for the real time determination of the thickness and information about the surface of studied samples with the resolution up to 7 nanometers. The determination of the characteristics of the medial cross-section of submicron-objects becomes possible due to phase sensitivity of interfering singular beams to the slightest changes in the optical path difference between them. The dependence of rotational angle of resulting interference pattern in case of different sample thickness for two singular beams superposition is considered in detail.This work was supported by the Russian Foundation for Basic Research (RFBR) and the Council of Ministers of Crimea grant № 19-42-910010, № 17-42-92020 and partially supported by the V. I. Vernadsky Crimean Federal University Development Program for 2015–2024 and Foundation for Assistance to Small Innovative Enterprises (Russian Federation) (Grant №11540GU/2017 (0033028). The results of the work were reported and discussed at the international conference “Digital singular optical optics”, September 17-21, 2018, Sevastopol

The persistence of memory in ionic conduction probed by nonlinear optics

Predicting practical rates of transport in condensed phases enables the rational design of materials, devices and processes. This is especially critical to developing low-carbon energy technologies such as rechargeable batteries1,2,3. For ionic conduction, the collective mechanisms4,5, variation of conductivity with timescales6,7,8 and confinement9,10, and ambiguity in the phononic origin of translation11,12, call for a direct probe of the fundamental steps of ionic diffusion: ion hops. However, such hops are rare-event large-amplitude translations, and are challenging to excite and detect. Here we use single-cycle terahertz pumps to impulsively trigger ionic hopping in battery solid electrolytes. This is visualized by an induced transient birefringence, enabling direct probing of anisotropy in ionic hopping on the picosecond timescale. The relaxation of the transient signal measures the decay of orientational memory, and the production of entropy in diffusion. We extend experimental results using in silico transient birefringence to identify vibrational attempt frequencies for ion hopping. Using nonlinear optical methods, we probe ion transport at its fastest limit, distinguish correlated conduction mechanisms from a true random walk at the atomic scale, and demonstrate the connection between activated transport and the thermodynamics of information

Effects of Sulfate Modification of Stoichiometric and Lithium-Rich LiNiO2 Cathode Materials

Lithium nickel oxide, LiNiO2, has attracted considerable interest as a high energy cathode for next generation lithium ion batteries. Nevertheless, shortcomings such as significant cycling capacity decay and low stability in ambient atmosphere have hindered its practical application, and consequently most work has focused on the more stable Mn and Co doped analogues Li(Ni,Mn,Co)O2. Here, we report an investigation of an alternative strategy, sulfate modification, in the LiNiO2 (LNO) system. We show that improved performance can be achieved, attributed to the dual effect of a low level of bulk doping and the presence of a self-passivation Li2SO4 layer formed beyond the solid solution limit. Ab initio simulations suggest that the behavior is similar to that of other high valent dopants such as W and Mo. These dual effects contribute to the improved air stability and enhanced electrochemical performance for the sulfate modified lithium-rich LNO, leading to high initial capacities (~245 mAhg-1 at 25 mA/g, and ~205 mAhg-1 at 100 mA/g) and better capacity retention. Overall, the results show that polyanion modification represents an excellent alternative low cost strategy to improve the performance of lithium nickel oxide cathode materials

Early carboniferous brachiopod faunas from the Baoshan block, west Yunnan, southwest China

38 brachiopod species in 27 genera and subgenera are described from the Yudong Formation in the Shidian-Baoshan area, west Yunnan, southwest China. New taxa include two new subgenera: Unispirifer (Septimispirifer) and Brachythyrina (Longathyrina), and seven new species: Eomarginifera yunnanensis, Marginatia cylindrica, Unispirifer (Unispirifer) xiangshanensis, Unispirifer (Septimispirifer) wafangjieensis, Brachythyrina (Brachythyrina) transversa, Brachythyrina (Longathyrina) baoshanensis, and Girtyella wafangjieensis. Based on the described material and constraints from associated coral and conodont faunas, the age of the brachiopod fauna from the Yudon Formation is considered late Tournaisian (Early Carboniferous), with a possibility extending into earlyViseacutean.<br /

State system in the USSR providing for planning and implementation of nature conservation programmes

Meeting: World Commission on Environment and Development, Public Hearing, 8, 11 Dec. 1986, Moskva, SURelated to DAP 87-4249 under which IDRC supported the WCED to acquire and duplicate original papers, submissions, tapes and transcripts, became the depository of all original archival materials and received the right to microfiche the collection for broader disseminatio

Study of hydrocarbon gas outputs distribution depending on geological structure of the Southern Caspian by gas survey

Актуальность исследования заключается в изучении газов верхней части разреза Южного Каспия, в особенности ее глубоководной части, представляющей значимый практический интерес при поисках и оценках углеводородного потенциала зон газогидратов. Анализ ранее проведенных работ в пределах Южного Каспия показал, что все исследования в основном сконцентрированы в пределах разбуренной зоны Абшеронского, Бакинского и Нижнекуринского нефтегазоносных районов и не охватывают глубоководную зону Южного Каспия. Цель исследования заключается в изучении распределения интенсивности проявления углеводородных газов по площади, выявлении зон газогенерации, а также проведении работ по определению и анализу путей миграции углеводородов и типов формирования газогидратов в пределах глубоководной зоны Южного Каспия. Объектом исследования послужили 1282 пробы газа, отобранные в Южном Каспии на месторождениях Шахдениз, Бахар, Пираллахи, Хали, в глубоководной части Южного Каспия и др., а также данные геолого-геофизических исследований. Использованы данные изучения химического и изотопного состава углеводородных газов Южно-Каспийской впадины по 147 пробам газа, отобранным из нефтегазовых месторождений, 153 пробам из грязевых вулканов, 29 пробам донных осадков и 4 пробам газогидратов. Эти данные позволили более обосновано подойти к анализу генетических вопросов происхождения газов в верхней части разреза. Методы исследования основаны на интерпретации данных газовой съемки и изучении изотопного и химического состава углеводородных газов Южного Каспия. Наличие точных значений координат, а также данных по структурным картам в координатной сетке позволили сопоставить имеющиеся данные с геологическим строением. В результате исследования построены карты изменения содержания метана, этана, пропана, бутана, изо-, нормального пентана в пределах верхней части разреза по изучаемым месторождениям. Сопоставлены данные результатов анализа газовой съемки с данными структурных карт и других геолого-геофизических материалов. Установлено, что структура Бахар характеризуется относительно пониженной интенсивностью газопровялений по метану от 5,37 × 10-4 до 152944 × 10-4 % (в среднем 9109,0354 × 10-4 %), в то время как месторождение Шахдениз характеризуется максимальными значениями от 4,6200 × 10-4 до 367840 × 10-4 %, в среднем составляя 85572,3 × 10-4 %. Небольшие значения интенсивности проявления газа, установленные в зоне структур Пираллахи, Хали, свидетельствуют о незначительном газовом потенциале глубокопогруженных отложений изучаемой зоны. Детально рассмотрены результаты газовой съемки в пределах глубоководной части Южного Каспия и установлено, что для этой зоны характерна газогенерация с преобладанием двух компонентов - метана и этана. Исходя из анализа изменения интенсивности проявления газа по площади и в зависимости от геологических условий установлено, что грязевые вулканы и разломы являются прекрасными путями для миграции углеводородов и отражают геологическую обстановку, генерационный потенциал погруженных отложений Южного Каспия. Установлено, что углеводородные газы в донных осадках и отложениях верхней части разреза Южной части Каспийского моря находятся в тесной зависимости от источников формирования углеводородов, миграции и других процессов, протекающих в глубокопогруженных отложениях, а также в верхней части разреза. Изучены данные химического и изотопного состава газов газогидратов, нефтяных и газовых месторождений Южного Каспия. На базе данных изотопно-геохимических исследований описаны механизмы образования гигантских месторождений нефти Балаханы-Сабунчи-Романы и газоконденсата Шахдениз, расположенных на одной антиклинальной зоне Абшеронского нефтегазоносного района, а также аномалии, выявленные по данным газовой съемки в пределах изучаемых структур Южного Каспия.The relevance of the research is in studying the gases of the Southern Caspian section upper part, in particular its deep-water part, which is of significant practical interest when searching and estimating hydrocarbon potential of gas hydrate zones. The analysis of the works carried out within the South Caspian showed that all the studies are mainly concentrated within the drilled zone of Absheron, Baku and Nizhnyaya Kura oil and gas regions, and do not cover the deep-sea zone of the Southern Caspian. The aim of the research is to study hydrocarbon gases intensity distribution by area, as well as to determine gas generation zones. In addition, the work was carried out to determine and analyze hydrocarbon migration routes and types of formation of gas hydrates within the deep-sea zone of the Southern Caspian. The object of the researchwas 1282 gas samples selected in the South Caspian at Shah Deniz, Bakhar, Pirallahi, Khali, deep-water South Caspian, and other geological and geophysical data. The data on chemical and isotope composition of the hydrocarbon gases of the South Caspian basin were used on 147 gas samples taken from oil and gas fields, 153 samples from mud volcanoes, 29 samples from bottom sediments and 4 samples from gas hydrates. These data enabled more reasonable approach to the analysis of genetic issues of gases origin in the upper part of the section. Research methods are based on interpretation of gas survey data and investigation of isotope and chemical composition of hydrocarbon gases of the Southern Caspian. The presence of exact values of coordinates, as well as data on structural maps in the grid, enabled to compare the available data with the geological structure. Result. The authors have constructed the maps of the change in the content of methane, ethane, propane, butane, iso-, normal pentane within the upper part of the section for the studied deposits and compared the data of the results of the analysis of gas survey with the data of structural maps and other geological and geophysical material. It is established that the structure of the Bakhar is characterized by a relatively low intensity of methane gas reservoirs from 5,37 × 10-4 to 152944 × 10-4 % (average 9109,0354 × 10-4 %), while the Shah Deniz field is characterized by the maximum values from 4,6200 × 10-4 to 367,840 × 10-4 %, an average of 85,572,3 × 10-4 %. Small values of gas intensity, established in the zone of the structures of Pirallakhi, Khali, indicate insignificant gas potential of deep-seated deposits of the studied zone. The results of the gas survey within the deep-water part of the South Caspian were considered in detail and it was established that for this zone gas generation is typical, with the predominance of two components - methane and ethane. Based on the analysis of the change in the intensity of gas manifestations by area and depending on geological conditions it was established that mud vol-canoes and faults are excellent ways for hydrocarbon migration and reflect the geological situation and the generation potential of the submerged deposits of the Southern Caspian. It was established that hydrocarbon gases in bottom sediments and sediments of the upper part of the South Caspian section are closely related to the sources of hydrocarbon formation, migration and other processes occurring in deeply buried sediments, as well as in upper part of the section. The authors studied the data of the chemical and isotopic composition of gas hydratesgases, oil and gas deposits of the South Caspian. Based on the data of isotope-geochemical studies the authors described the mechanisms of formation of giant oil deposits of Balakhany-Sabunchi-Romana and Shahdeniz gas condensate located on one anticlinal zone of the Absheron oil and gas bearing area, as well as anomalies revealed from gas survey data within the studied structures of the South Caspian