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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 181 records · Page 10

A materials-informatics based study of solid electrolytes and protective coatings for Li batteries

All-solid-state batteries with Li metal anode can address the safety issues surrounding traditional Li-ion batteries as well as the demand for higher energy densities. However, the development of solid electrolytes and protective coatings simultaneously possessing high ionic conductivity and wide electrochemical stability has proven to be a challenge. Here, we present a data-driven approach to explore the Li compound space for promising solid electrolytes and coatings. This is accomplished through the generation of a large database of battery-related materials properties of Li compounds by computing Li+ migration barriers using bond-valence-based pair potentials, and stability windows using density functional theory energies. Using this database, we implement machine learning models that can accurately predict migration barriers and electrochemical stability windows for any new Li compound. Through feature engineering, we ensure that our models are both accurate and interpretable. We perform feature importance analysis on our models to highlight materials properties that can be tuned for future design of coatings/electrolytes. Our database and informatics approach provide a valuable tool for the rapid discovery of new solid-state battery chemistries.

Solid state batteries↗

Hierarchically Structured Catalysts Toward Sustainable Hydrogen Economy: Electro‐ and Thermo‐Chemical Pathways

Abstract Hydrogen, as an important clean energy source, plays a more and more crucial role in decarbonizing the planet and meeting the global climate challenge due to its high energy density and zero‐emission. The demand for sustainable hydrogen is increasing drastically worldwide as driven by the global shift towards low‐carbon energy solutions. Thermochemical catalysis process dominates hydrogen production at scale given its relatively mature technology and commercialization status, as well as the established manufacturing infrastructure. While due to its environmentally friendly nature and growing abundant sources of renewable electricity, the electrochemical path for hydrogen production is rising as a major alternative to the thermochemical means. Nevertheless, hierarchically structured catalysts and devices have gradually taken the center stage toward replacing the traditional counterparts, especially with the rapid advancement of the design and manufacture of such ordered nanostructure assemblies toward high activity, efficient mass transport, and superb stability. In this review, the latest progress of the hierarchically structured catalysts for hydrogen production have been surveyed on electro‐ and thermo‐ chemical pathways comparatively. It covers the structure designs of atomic dispersion, nanoscale surfaces and interfaces for achieving highly active and durable catalysts, components, and devices. Both electrochemical and thermochemical approaches are reviewed in terms of the vast design details, engineered benefits, and understandings of various Pt‐group metal (PGM) and non‐PGM based transition metal catalysts for hydrogen production. As the growing trend, brief discussions are also presented toward the high‐level assembly and manufacture of complexly structured components and devices at scale in the electrochemical and thermochemical energy systems.

Deng, Chenxin↗

Ultrafast Preparation of Nonequilibrium FeNi Spinels by Magnetic Induction Heating for Unprecedented Oxygen Evolution Electrocatalysis

Carbon-supported nanocomposites are attracting particular attention as high-performance, low-cost electrocatalysts for electrochemical water splitting. These are mostly prepared by pyrolysis and hydrothermal procedures that are time-consuming (from hours to days) and typically difficult to produce a nonequilibrium phase. Herein, for the first time ever, we exploit magnetic induction heating-quenching for ultrafast production of carbon-FeNi spinel oxide nanocomposites (within seconds), which exhibit an unprecedentedly high performance towards oxygen evolution reaction (OER), with an ultralow overpotential of only +260 mV to reach the high current density of 100 mA cm -2 . Experimental and theoretical studies show that the rapid heating and quenching process (ca. 10 3 K s -1 ) impedes the Ni and Fe phase segregation and produces a Cl-rich surface, both contributing to the remarkable catalytic activity. Results from this study highlight the unique advantage of ultrafast heating/quenching in the structural engineering of functional nanocomposites to achieve high electrocatalytic performance towards important electrochemical reactions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Engineered MXene quantum dots for micro-supercapacitors with excellent capacitive behaviors

Micro-supercapacitors (MSCs) have drawn tremendous attention as promising candidates to power miniaturized portable/wearable electronics, but they still suffer from unsatisfactory electrochemical performance (e.g., insufficient energy density, mediocre rate capability), thus impeding their widespread applications. Here, a synergistic surface and structure engineering strategy achieved by downsizing to quantum dot scale, doping of heteroatoms, and introducing defects and functional groups is proposed to regulate the physicochemical properties of Ti 3 C 2 T x MXene. Encouragingly, the resulting MSCs based on defect-rich nitrogen-doped Ti 3 C 2 T x quantum dots (QDs) possess excellent electrochemical performance as demonstrated by large operating voltage (3.0 V in ionic liquid and 1.0 V in aqueous electrolyte), perfect rectangular CV shape even at 1000 V·s -1 , high volumetric capacitance of 33.1 F·cm -3 , and superior cycling stability after 10000 cycles. By employing experimental characterizations and density functional theory calculations, the remarkable performance of the MSCs is mainly due to the special chemical states as well as the unique surface and structural features of Ti 3 C 2 T x QDs, which offer abundant active sites, shorten ion diffusion pathways, promote ion/electron transports, and provide enhanced capacitance. Finally, this work provides a new strategy for the design of high-performance MSCs and a reference for the applications of MXene QDs in other energy-related fields.

42 ENGINEERING↗

Quantifying transport and electrocatalytic reaction processes in a gastight rotating cylinder electrode reactor via integration of Computational Fluid Dynamics modeling and experiments

Understanding the complexity of the multiple processes of mass, momentum, charge, and heat transport, and how these affect reaction kinetics at the electrode/electrolyte interface is one of the major challenges in the field of energy and catalysis. The rapid and rational scale-up of electrocatalytic systems to industrial scales require a detailed understanding of nonlinear transport-reaction processes, accessible only through the building of multi-physics models that capture with high fidelity the complexity of real-world devices. The gastight rotating cylinder electrode (RCE) reactor is a promising lab-scale tool that can decouple transport from intrinsic kinetics to generate data for first-principle models useful in the design of industrial, electrochemical reactors. Computational Fluid Dynamics (CFD) studies have previously been used to investigate the bulk flow in RCE reactors for simple corrosion and electroplating processes. However, the quantification of changes in local concentration within the viscous layer where catalysis takes place requires capturing the correct flow conditions inside the hydrodynamic boundary layer near the surface of the electrode. Further, this requires simulations with spatial resolution in the nm and μm scale and temporal resolutions between ms and s scales that are similar to the timescales for reactions on the electrode surface. In this study, experimental electrocatalysis is combined with CFD modeling to elucidate and parameterize the hydrodynamics in a gastight RCE reactor. CFD simulations of the electrochemical ferricyanide reduction reaction under mass transport limited conditions are used to evaluate the validity of the CFD model parameters by comparing calculated dimensionless mass transport descriptors to dimensionless correlations obtained experimentally. Justifications for assumptions and details of the simulation methods used in this study are presented to provide a detailed understanding of the effect that each model parameter has on the ability to accurately simulate electrocatalysis in RCE systems. The simulation methodology reported here is a first step towards the development of multi-scale models for the study of transport dependent electrocatalytic processes, such as the electrochemical transformation of CO 2 to fuels and chemicals.

42 ENGINEERING↗

Barefoot Rover: a Sensor-Infused Rover Wheel Demonstrating In-Situ Engineering and Science Extractions using Machine Learning

In this work, we demonstrate an instrumented wheel concept which utilizes a 2D pressure grid, an electrochemical impedance spectroscopy (EIS) sensor and machine learning (ML) to extract meaningful metrics from the interaction between the wheel and surface terrain. These include continuous slip/skid estimation, balance, and sharpness for engineering applications. Estimates of surface hydration, texture, terrain patterns, and regolith physical properties such as cohesion and angle of internal friction are additionally calculated for science applications. Traditional systems rely on post-processing of visual images and vehicle telemetry to estimate these metrics. Through in-situ sensing, these metrics can be calculated in near real time and made available to onboard science and engineering autonomy applications. This work aims to provide a deployable system for future planetary exploration missions to increase science and engineering capabilities through increased knowledge of the terrain.

Marchetti, Yuliya↗

Linking void and interphase evolution to electrochemistry in solid-state batteries using operando X-ray tomography

Despite progress in solid-state battery engineering, our understanding of the chemo-mechanical phenomena that govern electrochemical behavior and stability at solid-solid interfaces remains limited compared to solid-liquid interfaces. Here, we use operando synchrotron X-ray computed microtomography to investigate the evolution of lithium/solid-state electrolyte interfaces during battery cycling, revealing how the complex interplay among void formation, interphase growth, and volumetric changes determines cell behavior. Void formation during lithium stripping is directly visualized in symmetric cells, and the loss of contact that drives current constriction at the interface between lithium and the solid-state electrolyte (Li10SnP2S12) is quantified and found to be the primary cause of cell failure. The interphase is found to be redox-active upon charge, and global volume changes occur due to partial molar volume mismatches at either electrode. Finally, these results provide new insight into how chemo-mechanical phenomena can impact cell performance, which is necessary to understand for the development of solid-state batteries.

42 ENGINEERING↗

Interfacial Engineering of Metal Chalcogenides‐based Heterostructures for Advanced Sodium‐Ion Batteries

Sodium-ion batteries (SIBs) have become one of the most promising candidates for large-scale energy storage applications. Metal chalcogenides anode materials based on alloying or conversion reactions are widely studied because of their high theoretical capacities and rich redox reactions. However, their intrinsic limitations such as high voltage hysteresis and large volume expansion hinder their further applications. The construction of heterostructures has become an attractive strategy to alleviate the above issues. Here, the formation of built in electric fields (BIEFs) at the heterointerfaces will accelerate the migration of Na + and electrons. Moreover, heterostructures can also enhance the structural stability, generate more active sites and provide additional capacity. It is worth noting that heterointerfacial properties play a significant role in promoting the overall electrochemical performance of the heterostructures. However, a systematic understanding of their interfacial engineering is currently lacking. This article reviews the research progress of metal chalcogenides-based heterostructure anode materials in the near term. First, the definition, classification and the roles of heterostructures are introduced. Second, the detailed research progress of the metal chalcogenide-based heterostructures anodes in SIBs is discussed. Finally, the future prospects and potential research directions of the heterostructures for batteries are discussed.

anode↗

Enabling Mission Flexibility to Battery Driven Deep Space Endeavors With Generalized Battery-Health-Monitoring Using Physics-Based and Data-Driven Reduced-Order Models

The needs and requirements for an electrochemical energy storage for deep space exploration is well explored. It is often understood that different mission sites and environmental conditions require different battery chemistries or technologies. Additionally, various engineering solutions are deployed to overcome specific chemical challenges. One often overlooked need is the “health” monitoring of an electrochemical storage system. The term generalized health monitoring, as envisioned in this work, refers to the monitoring of various aspects such as electrode health, electrolyte health, reaction pathway health, cooling system health, sensor health, and BMS health [1]. Generalized health monitoring allows mission leads, engineers, and scientists to incorporate flexibility in mission designs, make on-the-fly mission changes, and extend the duration of science missions. Moreover, it enables automation and data-driven decision-making without compromising safety and performance. Recently, our group developed a hierarchy of thermal reduced-order models (TROM) by combining a physics-based modeling approach and data-driven model reduction techniques applied to flight data [2]. The resulting TROMs were found to be not only accurate but also identifiable from the flight data. Consequently, the coefficient of variance of the model parameters is small over the course of hundreds of flights, allowing for monitoring the parameter evolution trajectories as the battery ages and degrades. These parameters constitute the metrics of the generalized health of a battery. Monitoring their evolution allows such models to be used for anomaly detection and prognostics, improving early detection of abnormal behavior and thus enabling timely maintenance, longer battery life, and enhanced battery safety. For this presentation, the practicality of the thermal model will be validated on a pack of 14cells under various topology configurations such as 1S14P, 2P7S, 7S2P, and 1P14S. It is well known that manufacturing and non-uniform aging lead to variability in the performance of a cell, which is exacerbated by cell balancing during active load. Additionally, in extreme scenarios, the paramount objective is to complete the mission, regardless of the stresses on the battery. Topology-induced balancing issues further stress the battery. The goal of this study is to determine if the noise (identifiability) in the reduced-order thermal model parameters is sensitive to topology, cell spacing, cooling strategy, and manufacturing or age variability. The variability in cells is considered by assuming a multimodal distribution for microscopic parameters of a cell (such as porosity, tortuosity, reaction kinetics, volumetric thermal conductivity, and volumetric heat capacity). The compounded effect of manufacturing variability, topological selection, cooling strategies, and cell balancing ages each cell in a battery differently. The study aims to clarify whether the challenge in extracting maximum information depends on the minimum number of sensors or models used for data extraction.

Automation↗

Electrochemical and Hydrodynamic Interferences on the Performances of an Oxygen Microsensor with Built-in Electrochemical Microactuator

A concept of novel electrochemical in situ self-calibration technique for an oxygen microsensor has been proposed to devise a convenient calibration method without an externally coupled apparatus. Systemic investigations on the influences of various electrochemical (pH) and hydrodynamic (solution stirring) conditions on the proposed microsensor performances are presented. The results suggest that: 1) The calibrating microenvironments can be manipulated with carefully engineered sensor designs and optimized generating signals; 2) The external oxygen permeable membrane is needed to minimize the electrochemical and hydrodynamic interferences.

Kim, Chang-Soo↗

Tortuosity Engineering for Improved Charge Storage Kinetics in High-Areal-Capacity Battery Electrodes

The increasing demands of electronic devices and electric transportation necessitate lithium-ion batteries with simultaneous high energy and power capabilities. However, rate capabilities are often limited in high-loading electrodes due to the lengthy and tortuous ion transport paths with their electrochemical behaviors governed by complicated electrode architectures still elusive. Here, we report the electrode-level tortuosity engineering design enabling improved charge storage kinetics in high-energy electrodes. Both high areal capacity and high-rate capability can be achieved beyond the practical level of mass loadings in electrodes with vertically oriented architectures. The electrochemical properties in electrodes with various architectures were quantitatively investigated through correlating the characteristic time with tortuosity. The lithium-ion transport kinetics regulated by electrode architectures was further studied via combining the three-dimensional electrode architecture visualization and simulation. Finally, the tortuosity-controlled charge storage kinetics revealed in this study can be extended to general electrode systems and provide useful design consideration for next-generation high-energy/power batteries.

25 ENERGY STORAGE↗

Refurbishment of one-person regenerative air revitalization system

Regenerative processes for the revitalization of spacecraft atmospheres and reclamation of waste waters are essential for making long-term manned space missions a reality. Processes studied include: static feed water electrolysis for oxygen generation, Bosch carbon dioxide reduction, electrochemical carbon dioxide concentration, vapor compression distillation water recovery, and iodine monitoring. The objectives were to: provide engineering support to Marshall Space Flight Center personnel throughout all phases of the test program, e.g., planning through data analysis; fabricate, test, and deliver to Marshall Space Flight Center an electrochemical carbon dioxide module and test stand; fabricate and deliver an iodine monitor; evaluate the electrochemical carbon dioxide concentrator subsystem configuration and its ability to ensure safe utilization of hydrogen gas; evaluate techniques for recovering oxygen from a product oxygen and carbon dioxide stream; and evaluate the performance of an electrochemical carbon dioxide concentrator module to operate without hydrogen as a method of safe haven operation. Each of the tasks were related in that all focused on providing a better understanding of the function, operation, and performance of developmental pieces of environmental control and life support system hardware.

Powell, Ferolyn T.↗

Self‐Templated 3D Sulfide‐Based Solid Composite Electrolyte for Solid‐State Sodium Metal Batteries

Abstract Rechargeable solid‐state sodium metal batteries (SSMBs) experience growing attention owing to the increased energy density (vs Na‐ion batteries) and cost‐effective materials. Inorganic sulfide‐based Na‐ion conductors also possess significant potential as promising solid electrolytes (SEs) in SSMBs. Nevertheless, due to the highly reactive Na metal, poor interface compatibility is the biggest obstacle for inorganic sulfide solid electrolytes such as Na 3 SbS 4 to achieve high performance in SSMBs. To address such electrochemical instability at the interface, new design of sulfide SE nanostructures and interface engineering are highly essential. In this work, a facile and straightforward approach is reported to prepare 3D sulfide‐based solid composite electrolytes (SCEs), which utilize porous Na 3 SbS 4 (NSS) as a self‐templated framework and fill with a phase transition polymer. The 3D structured SCEs display obviously improved interface stability toward Na metal than pristine sulfide. The assembled SSMBs (with TiS 2 or FeS 2 as cathodes) deliver outstanding electrochemical cycling performance. Moreover, the cycling of high‐voltage oxide cathode Na 0.67 Ni 0.33 Mn 0.67 O 2 (NNMO) is also demonstrated in SSMBs using 3D sulfide‐based SCEs. This study presents a novel design on the self‐templated nanostructure of SCEs, paving the way for the advancement of high‐energy sodium metal batteries.

Guo, Xiaolin↗

Intermittent Defect Fluctuations in Oxide Heterostructures

Abstract The heterogeneous nature, local presence, and dynamic evolution of defects typically govern the ionic and electronic properties of a wide variety of functional materials. While the last 50 years have seen considerable efforts into development of new methods to identify the nature of defects in complex materials, such as the perovskite oxides, very little is known about defect dynamics and their influence on the functionality of a material. Here, the discovery of the intermittent behavior of point defects (oxygen vacancies) in oxide heterostructures employing X‐ray photon correlation spectroscopy is reported. Local fluctuations between two ordered phases in strained SrCoO x with different degrees of stability of the oxygen vacancies are observed. Ab‐initio‐informed phase‐field modeling reveals that fluctuations between the competing ordered phases are modulated by the oxygen ion/vacancy interaction energy and epitaxial strain. The results demonstrate how defect dynamics, evidenced by measurement and modeling of their temporal fluctuations, give rise to stochastic properties that now can be fully characterized using coherent X‐rays, coupled for the first time to multiscale modeling in functional complex oxide heterostructures. The study and its findings open new avenues for engineering the dynamical response of functional materials used in neuromorphic and electrochemical applications.

36 MATERIALS SCIENCE↗

Methylation enables the use of fluorine-free ether electrolytes in high-voltage lithium metal batteries

Lithium metal batteries represent a promising technology for next-generation energy storage, but they still suffer from poor cycle life due to lithium dendrite formation and cathode cracking. Fluorinated solvents can improve battery longevity by improving LiF content in the solid-electrolyte interphase; however, the high cost and environmental concerns of fluorinated solvents limit battery viability. Here, for this work, we designed a series of fluorine-free solvents through the methylation of 1,2-dimethoxyethane, which promotes inorganic LiF-rich interphase formation through anion reduction and achieves high oxidation stability. The anion-derived LiF interphases suppress lithium dendrite growth on the lithium anode and minimize cathode cracking under high-voltage operation. The Li + -solvent structure is investigated through in situ techniques and simulations to draw correlations between the interphase compositions and electrochemical performances. The methylation strategy provides an alternative pathway for electrolyte engineering towards high-voltage electrolytes while reducing dependence on expensive fluorinated solvents.

25 ENERGY STORAGE↗

Grain boundary engineering for efficient and durable electrocatalysis

Grain boundaries in noble metal catalysts have been identified as critical sites for enhancing catalytic activity in electrochemical reactions such as the oxygen reduction reaction. However, conventional methods to modify grain boundary density often alter particle size, shape, and morphology, obscuring the specific role of grain boundaries in catalytic performance. This study addresses these challenges by employing gold nanoparticle assemblies to control grain boundary density through the manipulation of nanoparticle collision frequency during synthesis. We demonstrate a direct correlation between increased grain boundary density and enhanced two-electron oxygen reduction reaction activity, achieving a significant improvement in both specific and mass activity. Additionally, the gold nanoparticle assemblies with high grain boundary density exhibit remarkable electrochemical stability, attributed to boron segregation at the grain boundaries, which prevents structural degradation. This work provides a promising strategy for optimizing the activity, selectivity, and stability of noble metal catalysts through precise grain boundary engineering.

36 MATERIALS SCIENCE↗