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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 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Rheological and microstructural characterization of aqueous suspensions of carbon black and reduced graphene oxide

Carbon black is often used as a conductivity enhancer in battery electrodes. Reduced graphene oxide is another conducting material, with a high aspect ratio sheet-like morphology, and offers the possibility of generating a conducting network at loadings that are small compared to carbon black. Suspensions of conducting carbon, active materials and binders are typically coated on current collectors during the formation of electrodes. The rheology of these suspensions is an important indicator of the connectivity of particles in the suspension and impacts the electrical conductivity as well as the thickness of the coated layer. In this work, the rheology and microstructures of aqueous suspensions of para-aminobenzoic acid terminated carbon black (CB) with and without reduced graphene oxide (RGO) were investigated. The CB loading varied between 0.05 wt.% -10 wt.%, while the samples containing RGO had an RGO loading of 0.05 wt.%. The pH of the suspension was varied from 7.5 to 3. The carboxyl groups on the CB surface are deprotonated at pH 7.5, making the particles hydrophilic. Protonation of the carboxylate groups at pH 3 makes the particles partially hydrophobic. Suspensions of CB showed Newtonian behavior at all loadings for pH 7.5, and at loadings below 1.5 wt.% for pH 3. They are shear thinning at loadings between 1.5–10 wt.%. Interestingly, the low shear viscosity is non-monotonic with CB loading, rising up to a CB loading of 7.5 wt.%, and then dropping at 10 wt.%. Cryogenic scanning electron microscopy (SEM) showed CB particles forming aggregates at pH 3 for CB loadings greater than 1.5 wt.%. At pH 3, addition of 0.05 wt.% RGO resulted in a viscosity increase for suspensions containing 0.5 wt.% CB, as the RGO formed connections with CB particles that enhanced network formation. Adding RGO had little effect on suspensions that had 1.5 wt.% CB. The combination of SEM imaging and suspension rheology provides insight into the particle connectivity for the carbon-based materials studied here. These insights will be useful in determining coating conditions for slurries used in rechargeable battery electrodes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2010

Rapid Active Sampling Package

A field-deployable, battery-powered Rapid Active Sampling Package (RASP), originally designed for sampling strong materials during lunar and planetary missions, shows strong utility for terrestrial geological use. The technology is proving to be simple and effective for sampling and processing materials of strength. Although this originally was intended for planetary and lunar applications, the RASP is very useful as a powered hand tool for geologists and the mining industry to quickly sample and process rocks in the field on Earth. The RASP allows geologists to surgically acquire samples of rock for later laboratory analysis. This tool, roughly the size of a wrench, allows the user to cut away swaths of weathering rinds, revealing pristine rock surfaces for observation and subsequent sampling with the same tool. RASPing deeper (.3.5 cm) exposes single rock strata in-situ. Where a geologist fs hammer can only expose unweathered layers of rock, the RASP can do the same, and then has the added ability to capture and process samples into powder with particle sizes less than 150 microns, making it easier for XRD/XRF (x-ray diffraction/x-ray fluorescence). The tool uses a rotating rasp bit (or two counter-rotating bits) that resides inside or above the catch container. The container has an open slot to allow the bit to extend outside the container and to allow cuttings to enter and be caught. When the slot and rasp bit are in contact with a substrate, the bit is plunged into it in a matter of seconds to reach pristine rock. A user in the field may sample a rock multiple times at multiple depths in minutes, instead of having to cut out huge, heavy rock samples for transport back to a lab for analysis. Because of the speed and accuracy of the RASP, hundreds of samples can be taken in one day. RASP-acquired samples are small and easily carried. A user can characterize more area in less time than by using conventional methods. The field-deployable RASP used a Ni/Cad rechargeable battery. Power usage was less than 1 Wh/ cm3 even when sampling strong basalts, so many samples could be taken on a single battery charge.

Peters, Gregory↗
DOE OSTI2022

Structure/Interface Coupling Effect for High-Voltage LiCoO 2 Cathodes

LiCoO 2 (LCO) is widely applied in today's rechargeable battery markets for consumer electronic devices. However, LCO operations at high voltage are hindered by accelerated structure degradation and electrode/electrolyte interface decomposition. To overcome these challenges, co-modified LCO (defined as CB-Mg-LCO) that couples pillar structures with interface shielding are successfully synthesized for achieving high-energy-density and structurally stable cathode material. Benefitting from the "Mg-pillar" effect, irreversible phase transitions are significantly suppressed and highly reversible Li + shuttling is enabled. Interestingly, bonding effects between the interfacial lattice oxygen of CB-Mg-LCO and amorphous Co x B y coating layer are found to elevate the formation energy of oxygen vacancies, thereby considerably mitigating lattice oxygen loss and inhibiting irreversible phase transformation. Meanwhile, interface shielding effects are also beneficial for mitigating parasitic electrode/electrolyte reactions, subsequent Co dissolution, and ultimately enable a robust electrode/electrolyte interface. As a result, the as-designed CB-Mg-LCO cathode achieves a high capacity and excellent cycle stability with 94.6% capacity retention at an extremely high cut-off voltage of 4.6 V. We report these findings provide new insights for cathode material modification methods, which serves to guide future cathode material design.

25 ENERGY STORAGE↗
DOE OSTI2020

Stabilized Co-Free Li-Rich Oxide Cathode Particles with An Artificial Surface Prereconstruction

Li-rich metal oxide (LXMO) cathodes have attracted intense interest for rechargeable batteries because of their high capacity above 250 mAh g –1 . However, the side effects of hybrid anion and cation redox (HACR) reactions, such as oxygen release and phase collapse that result from global oxygen migration (GOM), have prohibited the commercialization of LXMO. GOM not only destabilizes the oxygen sublattice in cycling, aggravating the well-known voltage fading, but also intensifies electrolyte decomposition and Mn dissolution, causing severe full-cell performance degradation. In this study, an artificial surface prereconstruction (ASR) for Li 1.2 Mn 0.6 Ni 0.2 O 2 particles with a molten-molybdate leaching is conducted, which creates a crystal-dense anion-redox-free LiMn 1.5 Ni 0.5 O 4 shell that completely encloses the LXMO lattice (ASR-LXMO). Differential electrochemical mass spectroscopy and soft X-ray absorption spectroscopy analyses demonstrate that GOM is shut down in cycling, which not only stabilizes HACR in ASR-LXMO, but also mitigates the electrolyte decomposition and Mn dissolution. ASR-LXMO displays greatly stabilized cycling performance as it retains 237.4 mAh g –1 with an average discharge voltage of 3.30 V after 200 cycles. More crucially, while the pristine LXMO cycling cannot survive 90 cycles in a pouch full-cell matched with a commercial graphite anode and lean (2 g A –1 h –1 ) electrolyte, ASR-LXMO shows high capacity retention of 76% after 125 cycles in full-cell cycling.

25 ENERGY STORAGE↗
DOE OSTI2021

Mesocrystallizing Nanograins for Enhanced Li + Storage

Morphology and crystallinity of electrode materials have a major effect on their charge carrier storage properties when applied in rechargeable batteries. While nanosizing electrode particles (with larger surface area) and maintaining electrode integrity are both good for performance enhancement, they seem to contradict each other and can be hardly well-balanced. Herein, we designed electrode particles consisting of numerous nanograins with uniform crystalline orientation to guarantee both high surface area and high structural integrity, allowing the significant improvement of Li + storage kinetics and performance. Applying this “mesocrystallizing” strategy to a NiCo 2 O 4 -based anode, resulting in various degrees of pseudocapacitance response, the long-term cyclability and rate performance of this material have been largely enhanced. Impressively, the mesocrystalline NiCo 2 O 4 electrode exhibits a high reversible capacity of 1403 mAh g -1 after 200 cycles at 1.6 A g -1 (a rate of 1.8 C). The growth mechanism of mesocrystalline materials with different morphologies is identified to be a topotactic strctural transition process featuring a gradual edge-to-core corrasion process. This work presents an important synthetic clue to balance the morpholgy and crystallinity of battery electrode materials for their perforamnce optimization and is expected to inspire future structural design for battery materials beyond the one prototyped here.

25 ENERGY STORAGE↗
DOE OSTI2022

Covalent Organic Framework as an Efficient Protection Layer for a Stable Lithium‐Metal Anode

Abstract Lithium (Li) metal shows great potential for achieving high‐energy‐density rechargeable batteries. However, the practical applications of Li‐metal batteries are still challenged by the formation of Li dendrites and unstable solid‐electrolyte interphase (SEI) on metallic Li. Herein, a thin covalent organic framework layer is in situ fabricated on Li (COF‐Li) to suppress Li dendrite growth and mitigate the side reaction on the Li anode. The COF has a periodic and uniform porosity, allowing for selectively sieving Li ions and guiding a uniform Li deposition. As a result, the COF‐Li exhibits a non‐dendrite morphology during repeated Li plating/stripping and demonstrates a remarkable cycle life over 13 200 h with an extremely low overpotential of only 16 mV at a high current density of 10 mA cm −2 and a high areal capacity of 10 mAh cm −2 .

He, Jiarui↗
DOE OSTI2022

Covalent Organic Framework as an Efficient Protection Layer for a Stable Lithium-Metal Anode

We report Lithium (Li) metal shows great potential for achieving high-energy-density rechargeable batteries. However, the practical applications of Li-metal batteries are still challenged by the formation of Li dendrites and unstable solid-electrolyte interphase (SEI) on metallic Li. Herein, a thin covalent organic framework layer is in situ fabricated on Li (COF-Li) to suppress Li dendrite growth and mitigate the side reaction on the Li anode. The COF has a periodic and uniform porosity, allowing for selectively sieving Li ions and guiding a uniform Li deposition. As a result, the COF-Li exhibits a non-dendrite morphology during repeated Li plating/stripping and demonstrates a remarkable cycle life over 13 200 h with an extremely low overpotential of only 16 mV at a high current density of 10 mA cm -2 and a high areal capacity of 10 mAh cm -2 .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

The Transference Number

The performance of rechargeable batteries and other electrochemical systems depends on the rate at which the working ion (often a cation) is transported from one electrode to the other. The cation transference number is an important transport parameter that affects this rate. The purpose of this perspective is to distinguish between approximate and rigorous methods used in the literature to measure the transference number. We emphasize the fact that this parameter is dependent on the reference frame used in the analysis; care must be taken when comparing values obtained from different sources to account for differences in reference frames. We present data obtained from a well‐characterized electrolyte. We compare rigorously determined transference numbers in two reference frames with values obtained by an approximate method. We conclude with a qualitative discussion of the relationship between the transference number and salt concentration gradients that are obtained when current is drawn through a battery.

Gao, Kevin W.↗
DOE OSTI2023

Electron energy levels determining cathode electrolyte interphase formation

Cathode electrolyte interphase (CEI) has a significant impact on the performance of rechargeable batteries and is gaining increasing attention. Understanding the fundamental and detailed CEI formation mechanism is of critical importance for battery chemistry. Herein, a diverse of characterization tools are utilized to comprehensively analyze the composition of the CEI layer as well as its formation mechanism by LiCoO 2 (LCO) cathode. We reveal that CEI is mainly composed of the reduction products of electrolyte and it only parasitizes the degraded LCO surface which has transformed into a disordered spinel structure due to oxygen loss and lithium depletion. Based on the energy diagram and the chemical potential analysis, the CEI formation process has been well explained, and the proposed CEI formation mechanism is further experimentally validated. This work highlights that the CEI formation process is nearly identical to that of the anode-electrolyte-interphase, both of which are generated due to the electrolyte directly in contact with the low chemical potential electrode material. This work can deepen and refresh our understanding of CEI.

LiCoO2↗
DOE OSTI2024

Infrared nanoimaging and nanospectroscopy of electrochemical energy storage materials and interfaces

Electrochemical interfaces are central to the function and performance of energy storage devices. Thus, the development of new methods to characterize these interfaces, in conjunction with electrochemical performance, is essential for bridging the existing knowledge gaps and accelerating the development of energy storage technologies. Of particular need is the ability to characterize surfaces or interfaces in a non-destructive way with adequate resolution to discern individual structural and chemical building blocks. To this end, sub-diffraction-limit low-energy infrared optical probes that exploit near-field interactions within atomic force microscopy platforms, such as pseudoheterodyne nanoimaging, photothermal nanoimaging and nanospectroscopy, and nanoscale Fourier transform infrared spectroscopy, are all powerful emerging techniques. These are capable of non-destructive surface probing and imaging at nanometer resolution. This review outlines recent efforts to characterize ex situ, in situ, and operando electrode materials and electrochemical interfaces in rechargeable batteries with these advanced infrared near-field probes.

25 ENERGY STORAGE↗
DOE OSTI2025

Metal hydrides: a historical perspective

Metal hydrides are known for their outstanding performance as materials for hydrogen storage and processing. These materials find applications for short- and long-term energy storage, compression and supply of hydrogen gas, thermal energy storage, as electrodes and electrolytes in rechargeable batteries, for the microstructural optimisation of functional materials, in thin film technologies, as catalysts, getters and in many other uses. After the discovery of the first binary metal hydrides back in the 19th century, their studies covered all possible binary M-H systems and expanded rapidly into the field of ternary hydrides following the recognition of the excellent hydrogen storage performance of LaNi 5 - and TiFe-based materials, which operate efficiently at room temperature and at near-ambient H 2 pressures. This review aims to provide an overview of the early works, as well as selected recent results on various classes of metal hydrides. It also covers the recent activities from the major contributing countries and continents, including USA, Europe, Japan, China and Australia. These studies relate to achieving the hydrogen storage systems goals set by the Department of Energy in the United States which inspired the research activities at the national and international level, through execution of the tasks on hydrogen-based energy storage managed by the International Energy Agency. The review is prepared by international experts in the field and covers the most important past developments and also presents the recent achievements in the field.

08 HYDROGEN↗
DOE OSTI2022

Modification of lithium electrodeposition behavior by variation of electrode distance

Developing a better understanding and control over the lithium electrodeposition behavior will assist with the commercial application of lithium metal anodes for rechargeable batteries. Despite intensive research over the past decade, our understanding of the deposition of lithium is limited. Here a new observation on the effect of distance between the working electrode and the counter electrode for electrochemical lithium deposition behavior is reported. From this fundamental investigation of distance, the high lithium ion concentration regions formed by release of lithium ions from the counter electrode modify the lithium deposition behavior on the working electrode, resulting in the generation of non-uniform lithium dendrites with a thick diversely composed surface film. Alternatively, increasing the distance between the electrodes results in the deposition of a spherical lithium morphology with a thin LiF rich surface film. Here, this fundamental study provides a deeper understanding of correlation between lithium deposition behavior and electrode separation and provides insight to inhibit lithium dendrite formation.

25 ENERGY STORAGE↗
DOE OSTI2026

Chemical beneficiation of cobaltiferous pyrite: a thermodynamic and parametric study

Despite ongoing efforts to identify substitute materials, cobalt remains indispensable for the production of rechargeable batteries essential to the global energy transition. Currently, most cobalt is sourced as a by-product of nickel and copper extraction from politically and ethically unstable regions. To address this vulnerability, certain primary cobalt deposits—where cobalt occurs within the crystal lattice of pyrite (FeS 2 )—have been identified as potential alternatives. Nonetheless, conventional beneficiation methods have proven largely ineffective for the potential processing of these minerals. This study investigated the thermal decomposition of cobaltiferous pyrite contained in flotation concentrates as a subsequent chemical beneficiation stage aimed at (i) selectively removing sulfur to further increase cobalt grades and (ii) producing a ferromagnetic product suitable for downstream magnetic separation. A thermodynamic analysis was first conducted to evaluate the feasibility of the decomposition reactions and the temperature-dependent evolution of sulfur species. A parametric experimental study then assessed the influence of temperature, residence time, and gas flow rate under N 2 and CO 2 atmospheres. Under the most favorable experimental conditions tested (650 °C, 15 min), cobalt grades increased by up to 15% with negligible cobalt losses and the co-production of high-purity sulfur (>95%). Magnetic separation of the resulting calcine yielded a final concentrate containing 2.09% cobalt at 82.5% recovery, representing a 16–74% improvement over previous baseline studies on similar feedstocks.

Beneficiation↗
DOE OSTI2020

Quantum prediction of ultra-low thermal conductivity in lithium intercalation materials

Lithium-intercalated layered transition-metal oxides, Li x TMO 2, brought about a paradigm change in rechargeable batteries in recent decades and show promise for use in memristors, a type of device for future neural computing and on-chip storage. Thermal transport properties, although being a crucial element in limiting the charging/discharging rate, package density, energy efficiency, and safety of batteries as well as the controllability and energy consumption of memristors, are poorly managed or even understood yet. Here, for the first time, we employ quantum calculations including high-order lattice anharmonicity and find that the thermal conductivity κ of Li x TMO 2 materials is significantly lower than hitherto believed. More specifically, the theoretical upper limit of κ of LiCoO 2 is 6 W/m-K, 2–6 times lower than the prior theoretical predictions. Delithiation further reduces κ by 40–70% for LiCoO 2 and LiNbO 2 . Grain boundaries, strain, and porosity are yet additional causes of thermal-conductivity reduction, while Li-ion diffusion and electrical transport are found to have only a minor effect on phonon thermal transport. The results elucidate several long-standing issues regarding the thermal transport in lithium-intercalated materials and provide guidance toward designing high-energy-density batteries and controllable memristors.

25 ENERGY STORAGE↗
DOE OSTI2022

Lithium metal stripping mechanisms revealed through electrochemical liquid cell electron microscopy

An understanding of lithium stripping is as important as that of lithium plating to achieve significant advances in using lithium metal anodes for high-energy rechargeable batteries. However, there have been limited studies on lithium stripping compared to lithium plating. Here we report the lithium stripping mechanisms revealed through in-situ electrochemical liquid cell transmission electron microscopy (TEM). We directly observe and compare the stripping behavior of the in-situ grown lithium dendrites and lithium nanograins covered by a lithium fluoride-rich solid-electrolyte interphase (SEI). Furthermore, we find the sporadic lithium stripping behavior and three important modes that can describe the stripping of individual lithium deposits, regardless of their morphology: (i) symmetric stripping, (ii) surface-preferred asymmetric stripping, and (iii) interface-preferred asymmetric stripping. In addition, SEI chemical mapping with high spatial resolution shows a remarkable SEI loss at the end of the lithium metal stripping, which illustrates the importance of SEI protection in the subsequent cycles.

25 ENERGY STORAGE↗
DOE OSTI2024

A novel polymeric lithicone coating for superior lithium metal anodes

Lithium metal (Li) is commonly regarded as the “holy grail” of rechargeable batteries and can serve as anodes for constituting various high-energy lithium metal batteries (LMBs). However, it suffers from two notorious issues: (1) continuous formation of inhomogeneous solid electrolyte interphase and (2) Li dendritic growth. Here, in this study, we developed a novel polymeric lithicone via a new molecular layer deposition (MLD) process, using lithium tert-butoxide (LTB) and hydroquinone (HQ) as precursors. We revealed that such an MLD process enabled the resultant LiHQ to grow linearly in a highly controllable and cyclic mode at a growth rate of 4 Å cycle −1 . Furthermore, its low process deposition temperature of 150 °C made it possible to practice high-quality coatings over Li anodes directly. We demonstrated that, very compellingly, this LiHQ coating could protect Li anodes from corrosion and dendritic growth. As a consequence, this LiHQ coating has enabled Li||Li symmetric cells an extremely long cyclability up to 8000 Li-plating/stripping cycles without failure. More excitingly, we demonstrated that, coupled with LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) cathodes, the LiHQ-modified Li anodes could help the resultant Li||NMC811 realize a much better capacity retention and much longer cyclability. Thus, this study represents a strategic route for developing commercializeable LMBs.

25 ENERGY STORAGE↗
DOE OSTI2021

U.S. lithium resources from geothermal and extraction feasibility

As the demand for electric vehicles (EVs) increases, demand for lithium (Li) is expected to grow over the coming decade. To satisfy the demand for rechargeable batteries, it is imperative to devise solutions for sufficient Li production. Additionally, even though commercial Li currently comes from conventional saline salar brine and spodumene ore extractions, efforts to retrieve Li from geothermal brines are increasing in popularity. In this paper, we evaluate the United States’ potential to supply Li from geothermal brines using Systems Dynamics modeling. The main goals are to assess (1) the viability of US Li supply from geothermal brines and (2) the potential supply chain impact of extracting Li from this source. Results show that Li supply from geothermal brines could (1) reach around 4% to 8% of total US Li supply and (2) be economically viable.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗