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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

One-step atmospheric microplasma synthesis of an NMC-type lithium-ion battery cathode

The manufacture of battery cathode materials is the most energy-intensive step in the production of commercial lithium-ion batteries; specifically, the synthesis of the widely used transition metal oxide cathodes can require tens of hours at temperatures exceeding 700 °C. Attempts to limit the reaction time and energy required to form crystalline cathode materials often still include a heating or calcination step. This communication aims to highlight a nascent yet novel synthesis route: a one-step atmospheric microplasma process for synthesizing cathode particles in less than one second. The hollow-tube reactor employed produces crystalline particles measuring 0.1–3 μm in diameter, displays narrow XRD peaks corresponding to the 003, 104, and 101 planes, and exhibits anodic redox behavior at 3.75 V vs. lithium—characteristic of transition-metal oxide cathode materials—all without requiring an additional calcination step.

25 ENERGY STORAGE↗
DOE OSTI2020

Techno-economic analysis of cathode material production using flame-assisted spray pyrolysis

The cost of cathode materials contributes approximately 32.7% of the total cell construction cost of lithium-ion batteries, significantly affecting the price of battery packs. To reduce the cathode material manufacturing cost, a flame-assisted spray pyrolysis (FSP) method has been developed to utilize a sustainable solvent of glycerol to manufacture the LiNi 1/3 Mn 1/3 Co 1/3 O 2 (NMC333) cathode materials. The purpose of this study is to evaluate the minimum cathode material selling price (MCSP) of the FSP processes compared with a traditional carbonate co-precipitation pathway. Results show that the MCSP of the FSP is $\$$19.1/kg that is 17% lower than the traditional carbonate co-precipitation pathway as a result of lower fixed operating cost and variable overhead. Sensitivity analysis shows that when the new process is integrated with in-situ sintering and processing, the MCSP can be as low as $\$$15.6/kg. When all the material prices are decreased by 20%, the FSP process can synthesize NMC333 at a price of $\$$2.3/kg lower. According to the simulation result, LiNi 0·8 Mn 0·1 Co 0·1 O 2 (NMC811) has the best potential to meet the U.S. Department of Energy battery price target of $\$$125/kWh, demonstrating that the FSP process is an attractive manufacturing technology for NMC cathode powder material production.

25 ENERGY STORAGE↗
DOE OSTI2021

A perspective on single-crystal layered oxide cathodes for lithium-ion batteries

As the demand for lithium-ion batteries grows exponentially to feed the nascent electric-vehicle and grid-storage markets, the need for higher energy density and longer cycle life becomes more apparent. Increasing the nickel content in the layered-oxide cathodes has been a dominant strategy to increase energy density, but this has exacerbated the surface reactivity concerns. Furthermore, the high states of charge associated with increased capacity lead to cracking of the polycrystalline cathode particles, which exposes fresh surfaces and accelerates capacity fade. Single-crystal cathode particles with low susceptibility to cracking have recently taken on intense interest due to their remarkable cyclability. Many different approaches to single-crystal synthesis have been explored, but there has been no systematic analysis of the different techniques to date. Additionally, many reports have taken on a trial-and-error approach, ignoring well established literature on grain growth outside the battery field. This perspective reviews the literature on single-crystal cathode synthesis through the lens of classic grain growth theories, providing insight and hopefully accelerating the adoption of the promising single-crystal cathode morphology.

25 ENERGY STORAGE↗
DOE OSTI2021

Extended cycle life implications of fast charging for lithium-ion battery cathode

Enabling extreme fast charging (XFC, =10–15 min charging) requires a comprehensive understanding of its implications. While lithium plating is a key bottleneck for the anode, the full extent of limitations for the cathode are not well-understood, particularly in extended-cycle settings with well-defined battery designs and conditions. This article presents cycle-life implications of XFC on cathodes at multiple length scales, combining electrochemical analyses, degradation modeling, and post-test characterizations. The comprehensive test matrix includes 41 well-defined gr/NMC pouch cells under varied fast-charge rates (1–9C) and state-of-charges cycled up to 1000 times. Cathode issues remain minimal in early cycling, but begin to accelerate in later life, when distinct cracking is found and identified as a fatigue mechanism. The bulk structure of cathodes remains intact, but distinct particle surface reconstruction is observed; however, this shows less pronounced effect on cathode aging than does cracking.

25 ENERGY STORAGE↗
DOE OSTI2026

Unraveling the Synergistic effects of La and Al co-doping on Ni/Co-free P2-type Na 0.67 Mn 0.67 Fe 0.33 O 2 layered oxide cathodes for sodium-ion batteries

Recent developments in high-performance cathodes for sodium-ion batteries (SIBs) tend to mitigate use of critical Ni and Co active species to satisfy sustainability. P2-type layered oxide cathodes based on Mn and Fe promise high capacity, sustainability, and low cost on account of the abundance and multiple redox characteristics of Mn and Fe. However, their commercialization is still challenged due to poor cycling stability caused by phase changes emanating from inherent Jahn-Teller distortions. Herein, we propose a novel strategy of trivalent La and Al co-doping to alleviate the drawbacks, innovating a new cathode of Na 0.67 Mn 0.62 Al 0.05 Fe 0.31 La 0.02 O 2 (AlLa). The co-doped cathode delivers an impressive capacity of 128.7 mAh/g at 1C and 106.5 mAh/g at high rate of 5C with a good capacity retention of 85% after 100 cycles. These are superior to the unmodified material, whose specific capacity was 118.6 mAh/g at 1C and 61.1 mAh/g at 5C with a retention of only 65% after 100 cycles. The synergistic contribution from La and Al associated with their improved oxygen bonding, pillaring, and local electronic structural modification stemming from rigid Lasingle bondO and Alsingle bondO bonding resulted in the observed structural and electrochemical improvement. Overall, this research offers novel strategies for designing high-performance cathode materials for sodium-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2024

Deep learning of experimental electrochemistry for battery cathodes across diverse compositions

Artificial intelligence (AI) has emerged as a tool for discovering and optimizing novel battery materials. However, the adoption of AI in battery cathode representation and discovery is still limited due to the complexity of optimizing multiple performance properties and the scarcity of high-fidelity data. Here, we present a machine learning model (DRXNet) for battery informatics and demonstrate the application in the discovery and optimization of disordered rocksalt (DRX) cathode materials. We have compiled the electrochemistry data of DRX cathodes over the past 5 years, resulting in a dataset of more than 19,000 discharge voltage profiles on diverse chemistries spanning 14 different metal species. Learning from this extensive dataset, our DRXNet model can capture critical features in the cycling curves of DRX cathodes under various conditions. Our approach offers a data-driven solution to facilitate the rapid identification of novel cathode materials, accelerating the development of next-generation batteries for carbon neutralization.

25 ENERGY STORAGE↗
DOE OSTI2022

Extreme fast charge aging: Correlation between electrode scale and heterogeneous degradation in Ni-rich layered cathodes

Extreme fast charging (XFC) is a key requirement for the adoption of battery-based electric vehicles by the transportation sector. However, XFC has been shown to accelerate degradation, causing the capacity, life, and safety of batteries to deteriorate. There are no systematic studies in the open literature regarding aging modes in Ni-rich Li y Ni 0.a Mn 0.b Co 0.c O 2 (NMCabc) cathodes caused by fast charging. Herein, we report the effects of cathode composition and electrode loading in pouch cells containing NMC532, 622 and 811 paired with graphite and cycled under XFC conditions. The relative anisotropic volume change in the unit cell increases with Ni content in low-loading cells, while it levels up for all three NMC cathodes in high-loading cells because of substantial Li plating. The amounts of lithium plating and heterogeneity on the anode, determined by crystallographic phase quantification, were found to be correlated with electrode loading and cathode heterogeneity. The concentrations of the transition metals deposited on the anodes depend on NMCabc composition in a complex way. More particle cracking and surface degradation was found in NMC811. Here, the findings in this work provide a new understanding of the failure mechanisms and their practical implications for compositional tuning of future high-Ni NMCabc cathode materials during fast charging.

25 ENERGY STORAGE↗
DOE OSTI2025

Bayesian optimization of entropy-stabilized metal fluoride conversion cathodes and their synthesis

Fluoride-based conversion cathodes are promising for next-generation Li ion batteries because of their high voltage and energy densities. High entropy earth abundant fluoride cathodes are attractive for sustainable battery because of the potentially higher cycling stability. While Ni and Co containing equimolar alloys stabilized by high entropy were considered previously, Ni and Co free non-equimolar metal alloy compositions might offer new opportunities to increase materials stability and average voltage. This opportunity was pursued using Bayesian optimization of average voltage for the computational prediction of (Fe x1 Cu x2 Zn x3 Mn x4 Mg x5 )F 2 cathode chemistries. Theoretical voltage, room temperature free energy, and electronic structure of potentially high voltage compositions were computed using density functional theory calculations. Here, the experimental realization of non-equimolar quinary Co and Ni free fluorides with stable rutile single phase and improved conversion reaction voltage by up to 28 % compared to the equimolar alloy demonstrated the power of Bayesian optimization methods for the computationally guided experimental synthesis of fluoride cathodes. Finally, non-equimolar cathode chemistries were found with cycling stability superior to known multi-element fluorides.

25 ENERGY STORAGE↗
DOE OSTI2021

A universal etching method for synthesizing high-performance single crystal cathode materials

LiNi x MnyCo 1-x-y O 2 (NMC) is considered the most appealing cathode material due to its high energy density and low cost. However, the stability and safety concerns, caused by the degradation of polycrystalline cathode materials during cycling, have restricted their practical applications. To overcome this shortcoming, converting polycrystalline cathode to high-performance single-crystal cathode materials becomes an appealing solution. In this work, a universal etching approach is firstly developed to synthesize single-crystal cathode materials. The rate performance of the obtained single-crystal NMC111 is 10–15% more than that of polycrystalline NMC111 whereas the capacity retention of single-crystal NMC111 is enhanced by ~12% after 300 cycles at 0.5C. The obtained single-crystal NMC622 exhibits a pronounced improvement in rate performance, especially at high rates (~28.6% better at 5C and ~129% better at 10C) and has a comparable cycle performance compared to polycrystalline NMC622. Altogether, the findings propose an alternative approach to generate single-crystal particles with high energy density and cycle stability for the next generation lithium-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2023

Fast Charge Induced Phase Evolution and Element Contribution of Nickel-Rich Layered Cathode for Lithium-Ion Batteries

In nickel-rich layered cathode materials, three transition metals (TM = Ni, Co and Mn) play critical roles in Li storage performance. However, rate-dependent phase evolution and elemental contribution of nickel-rich cathode materials are not well understood, but very important for further design and development of these cathodes in high-power applications. Here, the rate-dependent phase evolution and elemental contribution of LiNi 0.5 Mn 0.3 Co 0.2 O 2 (NMC532) cathode are investigated thoroughly by using time-resolved synchrotron-based in situ X-ray diffraction and absorption techniques. The increase of Ni content in NMC532 has been found to be the main cause of the complex structural changes, resulting in distortion of TM-O 6 octahedron and strong static vibration between TM and O coordination. It is revealed that the fast charge (10C and 30C) of NMC532 leads to intermediate Li-poor phases, shrinking of H2 phase region, and prolonged O1 phase. During high-rate charging, Co is oxidized easily in low voltage region, while Ni mainly dominates charge compensation in high voltage region. It is found that delithiation-induced local structure distortion transfers from Ni to Co sites in fast kinetic process. In conclusion, these findings provide in-depth understanding for the fast charge behavior of Ni-rich layered cathode materials and help to guide further development of advanced high-power lithium-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2023

Inhibit the strain accumulation for 5V spinel cathode by mitigating the phase separation during high voltage stage

LiNi 0.5 Mn 1.5 O 4 (LNMO) spinel cathode is a potential cathode material for high-power, low-cost lithium-ion batteries (LIBs) due to its low raw material cost, high operating voltage and efficient lithium-ion transport channel. However, LNMO suffers from structural stability due to the two-phase-transformation during charge/discharge process, leading to poor cycling performance. Here, to address the issues, we have constructed a homogeneous aggregated LNMO cathode with a multifaceted primary particle, namely the LNMO with single-crystal secondary particles (SSP LNMO). Ex situ and in situ characterizations including the synchrotron X-ray diffraction, the neutron diffraction and full pouch cell validated that the SSP LNMO exhibit a single solid-solution reactions with a restrained lattice evolution during the delithiation/lithiation process. This is in contrast to the normal LNMO cathode, which demonstrates a significant two-phase transition from spinel Li 1-x Ni 0.5 Mn 1.5 O 4 to rock-salt MnO 2 at high voltage. Therefore, the SSP LNMO has greatly improved cycle life compared to the normal LNMO cathode. Overall, this study demonstrates the possibility of constructing LNMO based on primary-grain morphology modulation to improve the intrinsic stability of LIBs.

25 ENERGY STORAGE↗
DOE OSTI2019

Toward Long-Life, Ultrahigh-Nickel Layered Oxide Cathodes for Lithium-Ion Batteries: Optimizing the Interphase Chemistry with a Dual-Functional Polymer

Boosting the Ni content in LiMO 2 (M = Ni, Co, Mn, etc.) layered oxides is a promising way to establish high-energydensity, low-cost cathodes, but the poor cathode surface stability is a daunting challenge for their practical viability. Herein, by constructing a dual-functional binder framework with a conductive polymer - polyaniline (PANI), the ultrahigh-Ni layered oxide cathode (LiNi 0.94 Co 0.06 O 2 ) exhibits significantly improved cyclability, with a capacity retention greatly increased from 47% to 81% over 1,000 cycles in full cells. It is demonstrated that the acidic species (e.g. HF) in the electrolyte can be efficiently scavenged through a protonation process of PANI, hence the cathode surface reactivity is greatly suppressed and the rock-salt phase propagation into bulk structure is considerably alleviated. Furthermore, the PANI binder system effectively prevents both the cathode-electrolyte interphase (CEI) and anode-electrolyte interphase (AEI) from degrading to a thick “triple-layer” architecture upon extensive cycling, resulting in more robust, thinner CEI and AEI with regulated interphasial chemistry. Moreover, the delocalized π-conjugated electrons along the backbone of PANI facilitate fast electron transfer and promote rate capability even at low temperatures (-20 °C). Finally, this work sheds light on rational binder engineering for developing high-energy-density lithium-ion batteries with acceptable cycle life.

25 ENERGY STORAGE↗
DOE OSTI2022

Removal of Surface Carbonate from Lithium-Ion Battery Cathode Materials via Vapor-Phase Fluorination

Herein, ultrathin metal-fluoride barrier coatings on the surface of lithium-ion battery (LIB) cathodes can improve cycling stability and prevent corrosion by acidic byproducts in the electrolyte. Atomic layer deposition (ALD) is an effective method to deposit ultrathin metal fluoride coatings on LIB cathodes. Although numerous studies have demonstrated the benefit of ALD metal fluoride coatings to LIB performance, comparatively few works have examined the effect of individual ALD precursors on the cathode surface. This paper uses X-ray photoelectron spectroscopy (XPS) measurements to elucidate the surface chemical changes on LIB cathode material surfaces upon exposure to the ALD metal fluoride precursor, hydrogen fluorine pyridine (HFPy). We found a decrease in surface carbonate and an increase in surface fluoride after HFPy exposure suggesting the conversion of lithium carbonate (Li 2 CO 3 ) to lithium fluoride (LiF). This conversion is desirable given that Li 2 CO 3 degrades LIB performance, whereas LiF provides an excellent physio-chemical barrier against chemical attack during cycling. Scanning transmission electron microscopy, X-ray energy dispersive spectroscopy, and XPS measurements following HFPy exposure to Li 2 CO 3 powder revealed the formation of a conformal LiF shell around the Li 2 CO 3 particles. Finally, we confirmed the complete conversion of similar to 7 nm ALD Li 2 CO 3 films on silicon from HFPy exposure using XPS and spectroscopic ellipsometry. The elimination of problematic Li 2 CO 3 from LIB cathode surfaces and conversion into a protective LiF coating via a single precursor vapor treatment may provide a cost-effective method for enhancing LIB performance.

25 ENERGY STORAGE↗
DOE OSTI2024

Multinonmetal-Doped V 2 O 5 Nanocomposites for Lithium-Ion Battery Cathodes

Lithium-ion batteries (LIBs) are critical for portable electronics and electric vehicles, demanding higher energy density to meet increasing energy storage needs. Current commercial cathode materials, such as LiFePO 4 and LiCoO 2 , are limited by a single electron transfer, restricting their energy density. Vanadium pentoxide (V 2 O 5 ) emerges as a promising high-capacity cathode due to its high theoretical capacity of 443 mA h g –1 with three Li storage capacities, significantly surpassing conventional materials. However, the practical application of V 2 O 5 is hindered by a large structural evolution and rapid capacity fading during full lithium intercalation. Here, this study introduces a multinonmetal doping (MNM) strategy to enhance V 2 O 5 cathodes by incorporating all-nonmetal dopants (B, P, and Si) and graphene (G). MNM-V 2 O 5 -G exhibits increased surface oxygen defects, improving charge transfer kinetics and thus enhancing the rate performance and cycling stability. Our results provide valuable insights into the role of surface oxygen defects in stabilizing V 2 O 5 with element doping. This research highlights the potential of multinonmetal doping to improve LIB cathode materials, offering a promising pathway for design of high-energy-density V 2 O 5 cathodes and advancing the development of next-generation energy storage solutions.

25 ENERGY STORAGE↗
DOE OSTI2020

Rational Designed Mixed-Conductive Sulfur Cathodes for All-Solid-State Lithium Batteries

All-solid-state lithium–sulfur batteries (ASSLSBs) hold great promise for safe and high-energy-density energy storage. However, developing high-performance sulfur cathodes has been proven difficult due to low electronic and ionic conductivities and large volume change of sulfur during charge and discharge. Here, we reported an approach to synthesize sulfur cathodes with a mixed electronic and ionic conductivity by infiltrating a solution consisting of Li 3 PS 4 (LPS) solid electrolyte and S active material into a mesoporous carbon (CMK-3). This approach leads to a uniform dispersion of amorphous Li 3 PS 7 (L 3 PS) catholyte in an electronically conductive carbon matrix, enabling high and balanced electronic/ionic conductivities in the cathode composite. The inherent porous structure of CMK-3 also helps to accommodate the strain/stress generated during the expansion and shrinkage of the active material. In sulfide-based all-solid-state batteries with Li metal as the anode, this cathode composite delivered a high capacity of 1025 mAh g –1 after 50 cycles at 60 °C at 1/8C. This work highlights the important role of high and balanced electronic and ionic conductivities in developing high-performance sulfur cathodes for ASSLSBs.

25 ENERGY STORAGE↗
DOE OSTI2022

High Nickel and No Cobalt - The Pursuit of Next-Generation Layered Oxide Cathodes

The prosperity of the electric vehicle industry is driving the research and development of lithium-ion batteries. As one of the core components in the entire battery system, cathode materials are currently facing major challenges in pushing higher capacity up to their theoretical limits and transitioning away from the unaffordable metals. To meet these requirements, the search for next-generation cathode materials has shifted to high-nickel and cobalt-free cathodes. In this review, we distinctly pointed out the shortcomings of cobalt in stabilizing layered structures, and systematically summarized the recent efforts to eliminate cobalt and achieve higher nickel content in layered cathode materials. Lastly, a reasonable prospect is put forward for further development of layered cathode materials and other promising candidates, which is likely to spur a wave of efforts toward developing high-performance and low-cost Li-ion batteries.

25 ENERGY STORAGE↗
DOE OSTI2022

Electrolyte Reactivity at the Charged Ni-Rich Cathode Interface and Degradation in Li-Ion Batteries

The chemical and electrochemical reactions at the positive electrode–electrolyte interface in Li-ion batteries are hugely influential on cycle life and safety. Ni-rich layered transition metal oxides exhibit higher interfacial reactivity than their lower Ni-content analogues, reacting via mechanisms that are poorly understood. Here, we study the pivotal role of the electrolyte solvent, specifically cyclic ethylene carbonate (EC) and linear ethyl methyl carbonate (EMC), in determining the interfacial reactivity at charged LiNi 0.33 Mn 0.33 Co 0.33 O 2 (NMC111) and LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) cathodes by using both single-solvent model electrolytes and the mixed solvents used in commercial cells. While NMC111 exhibits similar parasitic currents with EC-containing and EC-free electrolytes during high voltage holds in NMC/Li 4 Ti 5 O 12 (LTO) cells, this is not the case for NMC811. Online gas analysis reveals that the solvent-dependent reactivity for Ni-rich cathodes is related to the extent of lattice oxygen release and accompanying electrolyte decomposition, which is higher for EC-containing than EC-free electrolytes. Combined findings from electrochemical impedance spectroscopy (EIS), TEM, solution NMR, ICP, and XPS reveal that the electrolyte solvent has a profound impact on the degradation of the Ni-rich cathode and the electrolyte. Higher lattice oxygen release with EC-containing electrolytes is coupled with higher cathode interfacial impedance, a thicker oxygen-deficient rock-salt surface reconstruction layer, more electrolyte solvent and salt breakdown, and higher amounts of transition metal dissolution. These processes are suppressed in the EC-free electrolyte, highlighting the incompatibility between Ni-rich cathodes and conventional electrolyte solvents. Finally, new mechanistic insights into the chemical oxidation pathways of electrolyte solvents and, critically, the knock-on chemical and electrochemical reactions that further degrade the electrolyte and electrodes curtailing battery lifetime are provided.

25 ENERGY STORAGE↗
DOE OSTI2024

A Carbonyl and Azo-Based Polymer Cathode for Low-Temperature Na-Ion Batteries

Due to flexible structure tunability and abundant structure diversity, redox-active polymers are promising cathode materials for developing affordable and sustainable Na-ion batteries (NIBs). However, polymer cathodes still suffer from low capacity, poor cycle life, and sluggish reaction kinetics. Herein, we designed and synthesized a polymer cathode material bearing carbonyl and azo groups as well as extended conjugation structures in the repeating units. The polymer cathode exhibited exceptional electrochemical performance in NIBs in terms of high capacity, long lifetime, and fast kinetics. When coupled with a low-concentration electrolyte, it shows superior performance at low temperatures down to -50 °C, demonstrating great promise for low-temperature battery applications. Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) were employed to study the reaction mechanism, interphase structure, and morphological evolution, confirming reversible redox reactions between azo/carbonyl groups in the polymer and Na + /electrons, a NaF-rich interphase, and high structure stability upon cycling. In conclusion, this work provides an effective approach to developing high-performance polymer cathodes for affordable, sustainable, and low-temperature NIBs.

25 ENERGY STORAGE↗