Quantitative Analysis of Sodium Metal Deposition and Interphase in Na Metal Batteries

Sodium-ion batteries exhibit significant promise as a viable alternative to current lithium-ion technologies owing to their sustainability, low cost per energy density, reliability, and safety. Despite recent advancements in cathode materials for this category of energy storage systems, the primary challenge in realizing practical applications of sodium-ion systems is the absence of an anode system with high energy density and durability. Although Na metal is the ultimate anode that can facilitate high-energy sodium-ion batteries, its use remains limited due to safety concerns and the high-capacity loss associated with the high reactivity of Na metal. In this study, titration gas chromatography is employed to accurately quantify the sodium inventory loss in ether- and carbonate-based electrolytes. Uniaxial pressure is developed as a powerful tool to control the deposition of sodium metal with dense morphology, thereby enabling high initial coulombic efficiencies. In ether-based electrolytes, the Na metal surface exhibits the presence of a uniform solid electrolyte interphase layer, primarily characterized by favorable inorganic chemical components with close-packed structures. The full cell, utilizing a controlled electroplated sodium metal in ether-based electrolyte, provides capacity retention of 91.84% after 500 cycles at 2C current rate and delivers 86 mAh/g discharge capacity at 45C current rate, suggesting the potential to enable Na metal in the next generation of sodium-ion technologies with specifications close to practical requirements

3D time series analysis of cell shape using Laplacian approaches

Background: Fundamental cellular processes such as cell movement, division or food uptake critically depend on cells being able to change shape. Fast acquisition of three-dimensional image time series has now become possible, but we lack efficient tools for analysing shape deformations in order to understand the real three-dimensional nature of shape changes. Results: We present a framework for 3D+time cell shape analysis. The main contribution is three-fold: First, we develop a fast, automatic random walker method for cell segmentation. Second, a novel topology fixing method is proposed to fix segmented binary volumes without spherical topology. Third, we show that algorithms used for each individual step of the analysis pipeline (cell segmentation, topology fixing, spherical parameterization, and shape representation) are closely related to the Laplacian operator. The framework is applied to the shape analysis of neutrophil cells. Conclusions: The method we propose for cell segmentation is faster than the traditional random walker method or the level set method, and performs better on 3D time-series of neutrophil cells, which are comparatively noisy as stacks have to be acquired fast enough to account for cell motion. Our method for topology fixing outperforms the tools provided by SPHARM-MAT and SPHARM-PDM in terms of their successful fixing rates. The different tasks in the presented pipeline for 3D+time shape analysis of cells can be solved using Laplacian approaches, opening the possibility of eventually combining individual steps in order to speed up computations

Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

Lithographic manufacturing of adaptive optics components

Adaptive optics systems and their laboratory test environments call for a number of unusual optical components. Examples include lenslet arrays, pyramids, and Kolmogorov phase screens. Because of their specialized application, the availability of these parts is generally limited, with high cost and long lead time, which can also significantly drive optical system design. These concerns can be alleviated by a fast and inexpensive method of optical fabrication. To that end, we are exploring direct-write lithographic techniques to manufacture three different custom elements. We report results from a number of prototype devices including 1, 2, and 3 wave Multiple Order Diffractive (MOD) lenslet arrays with 0.75 mm pitch and phase screens with near Kolmogorov structure functions with a Fried length r(0) around 1 mm. We also discuss plans to expand our research to include a diffractive pyramid that is smaller, lighter, and more easily manufactured than glass versions presently used in pyramid wavefront sensors. We describe how these components can be produced within the limited dynamic range of the lithographic process, and with a rapid prototyping and manufacturing cycle. We discuss exploratory manufacturing methods, including replication, and potential observing techniques enabled by the ready availability of custom components.SPIE grants to authors of papers published in an SPIE Journal or Proceedings the right to post an author-prepared version or an official version (preferred version) of the published paper on an internal or external server controlled exclusively by the author/employer, provided that (a) such posting is noncommercial in nature and the paper is made available to users without charge; (b) an appropriate copyright notice and full citation appear with the paper, and (c) a link to SPIE's official online version of the abstract is provided using the DOI (Document Object Identifier) link.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

The information for interception: an in-situ examination of the timing of the visual information pick-up by cricket batsmen of different skill levels

The purpose of this study was to examine the respective contributions of advance, ball flight, and ball bounce information to expert interception in the skill of cricket batting using an experimental task that preserved as many of the natural constraints as possible. Six highly skilled and six low-skilled batsmen attempted to hit balls delivered by fast bowlers under conditions in which vision of the bowler’s prerelease movement patterns and the subsequent ball flight were selectively and unpredictably occluded using liquid crystal spectacles. Vision was occluded either just prior to ball release, just prior to ball bounce, or not at all, creating conditions in which only advance information arising from the bowler’s movement pattern was progressively supplemented by the availability of early pre-bounce and late post-bounce ball flight information. The bowlers delivered balls of two different types either swinging away or into the batsman and two different lengths either bouncing close to or well short of the batsman and the interest was in determining the accuracy of both the whole-body positioning movements and the finer bat-positioning movements of the batsmen. The former was measured by the appropriateness of the definitive foot movements made by the batsmen forward for balls bouncing close and back for balls bouncing short and the latter by quality of bat-ball contacts (cf. Müller & Abernethy, in press). The highly skilled players were superior to the less-skilled players in the number of correct definitive foot movements made across all conditions when the ball was of full length and in the release condition when the ball was delivered at a short length. In relation to bat-ball contact, the more skilled players were able to utilize information both prior to and after ball bounce to attain a greater number of “good” contacts. The in-situ occluding method reveals aspects of expertise not apparent within traditional laboratory measures of anticipation and may, consequently, also have utility for the training of interceptive skill

Fabrication of High-Quality Thin Solid-State Electrolyte Films Assisted by Machine Learning

International audienceSolid-state electrolytes (SSEs) are promising candidates to circumvent flammability concerns of liquid electrolytes. However, enhancing energy densities by thinning SSE layers and enabling scalable coating processes remain challenging. While previous studies have addressed thin and flexible SSEs, mainly ionic conductivity was considered for performance evaluation, and no systematic research on the effects of manufacturing conditions on the quality of SSE films was performed. Here, both uniformity and ionic conductivity are considered for evaluating the SSE films under the guidance of machine learning (ML). Three algorithms, principal component analysis, K-means clustering, and support vector machine, are employed to decipher the interdependencies between manufacturing conditions and film performance. Guided by ML, a 40 mu m SSE film with high ionic conductivity and good uniformity is used to construct a LiNi0.8Co0.1Mn0.1O2 parallel to Li6PS5Cl parallel to LiIn cell demonstrating 100 cycles. This study presents an efficient ML-assisted approach to optimize scalable production of high-quality SSE films

Quantitative analysis of sodium metal deposition and interphase in Na metal batteries

Sodium-ion batteries exhibit significant promise as a viable alternative to current lithium-ion technologies owing to their sustainability, low cost per energy density, reliability, and safety. Despite recent advancements in cathode materials for this category of energy storage systems, the primary challenge in realizing practical applications of sodium-ion systems is the absence of an anode system with high energy density and durability. Although Na metal is the ultimate anode that can facilitate high-energy sodium-ion batteries, its use remains limited due to safety concerns and the high-capacity loss associated with the high reactivity of Na metal. In this study, titration gas chromatography is employed to accurately quantify the sodium inventory loss in ether- and carbonate-based electrolytes. Uniaxial pressure is developed as a powerful tool to control the deposition of sodium metal with dense morphology, thereby enabling high initial coulombic efficiencies. In ether-based electrolytes, the Na metal surface exhibits the presence of a uniform solid electrolyte interphase layer, primarily characterized by favorable inorganic chemical components with close-packed structures. The full cell, utilizing a controlled electroplated sodium metal in ether-based electrolyte, provides capacity retention of 91.84% after 500 cycles at 2C current rate and delivers 86 mA h g−1 discharge capacity at 45C current rate, suggesting the potential to enable Na metal in the next generation of sodium-ion technologies with specifications close to practical requirements

Evaluating Electrolyte-Anode Interface Stability in Sodium All-Solid-State Batteries.

All-solid-state batteries have recently gained considerable attention due to their potential improvements in safety, energy density, and cycle-life compared to conventional liquid electrolyte batteries. Sodium all-solid-state batteries also offer the potential to eliminate costly materials containing lithium, nickel, and cobalt, making them ideal for emerging grid energy storage applications. However, significant work is required to understand the persisting limitations and long-term cyclability of Na all-solid-state-based batteries. In this work, we demonstrate the importance of careful solid electrolyte selection for use against an alloy anode in Na all-solid-state batteries. Three emerging solid electrolyte material classes were chosen for this study: the chloride Na2.25Y0.25Zr0.75Cl6, sulfide Na3PS4, and borohydride Na2(B10H10)0.5(B12H12)0.5. Focused ion beam scanning electron microscopy (FIB-SEM) imaging, X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS) were utilized to characterize the evolution of the anode-electrolyte interface upon electrochemical cycling. The obtained results revealed that the interface stability is determined by both the intrinsic electrochemical stability of the solid electrolyte and the passivating properties of the formed interfacial products. With appropriate material selection for stability at the respective anode and cathode interfaces, stable cycling performance can be achieved for Na all-solid-state batteries

Synthetic control of structure and conduction properties in Na–Y–Zr–Cl solid electrolytes

In the development of low cost, sustainable, and energy-dense batteries, chloride-based compounds are promising catholyte materials for solid-state batteries owing to their high Na-ion conductivities and oxidative stabilities. The ability to further improve Na-ion conduction, however, requires an understanding of the impact of long-range and local structural features on transport in these systems. In this study, we leverage different synthesis methods to control polymorphism and cation disorder in Na-Y-Zr-Cl solid electrolytes and interrogate the impact on Na-ion conduction. We demonstrate the existence of a more conductive P21/n polymorph of Na2ZrCl6 formed upon ball milling. In Na3YCl6, the R3̄ polymorph is shown to be more conductive than its P21/n counterpart owing to the presence of intrinsic vacancies and disorder on the Y sublattice. Transition metal ordering in the Na2.25Y0.25Zr0.75Cl6 composition strongly impacts Na-ion transport, where a greater mixing of Y3+ and Zr4+ on the transition metal sublattice facilitates ion migration through partial activation of Cl rotations at relevant temperatures. Overall, Na-ion transport sensitively depends on the phases and transition metal distributions stabilized during synthesis. These results are likely generalizable to other halide compositions and indicate that achieving control over the synthetic protocol and resultant structure is key in the pursuit of improved catholytes for high voltage solid-state sodium-ion batteries

High-performing All-solid-state Sodium-ion Batteries Enabled by the Presodiation of Hard Carbon

All-solid-state sodium ion batteries (AS3iBs) are highly sought after for stationary energy storage systems due to their suitable safety and stability over a wide temperature range. Hard carbon (HC), which is low cost, exhibits a low redox potential, and a high capacity, is integral to achieve a practical large-scale sodium-ion battery. However, the energy density of the battery utilizing this anode material is hampered by its low initial Coulombic efficiency (ICE). Herein, two strategies, namely (i) thermal treatment and (ii) presodiation by thermal decomposition of NaBH4, are explored to improve the ICE of pristine HC. Raman spectroscopy, X-ray photoelectron spectroscopy and electrochemical characterizations elucidate that the thermal treatment increases the Csp2 content in the HC structure, while the presodiation supplies the sodium to occupy the intrinsic irreversible sites. Consequently, presodiated HC exhibits an outstanding ICE (>99%) compared to the thermally treated (90%) or pristine HC (83%) in half-cell configurations. More importantly, AS3iB using presodiated HC and NaCrO2 as the anode and cathode, respectively, exhibits a high ICE of 92% and an initial discharge energy density of 294 Wh kg_cathode^(-1