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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Voltage-Based Strategies for Preventing Battery Degradation under Diverse Fast-Charging Conditions

Maintaining safe operating conditions is a key challenge for high-performance lithium-ion battery applications. The lithium-plating reaction remains a risk during charging, but limited studies consider the highly variable charging conditions possible in commercial cells. Here we combine pseudo-2D electrochemical modeling with data visualization methods to reveal important relationships between the measurable cell voltage and difficult-to-predict Li-plating onset criteria. An extensively validated model is used to compute Li plating for thousands of multistep charging conditions spanning diverse rates, temperatures, states-of-charge, and cell aging. Here we observe an empirical cell operating voltage limit below which plating does not occur across all conditions, and this limit varies with the battery state-of-charge and aging. A model sensitivity analysis also indicates that, when comparing two charging voltage profiles, the capacity difference at 4.0 V correlates well with the difference in the plating onset capacity. These results encourage simple strategies for Li-plating prevention that are complementary to existing battery controls.

25 ENERGY STORAGE↗
DOE OSTI2024

Defect Chemistry in High‐Voltage Cathode Materials for Lithium‐Ion Batteries

High-voltage cathodes (HVCs) have emerged as a paramount role for the next-generation high-energy-density lithium-ion batteries (LIBs). However, the pursuit of HVCs comes with inherent challenges related to defective structures, which significantly impact the electrochemical performance of LIBs. The current obstacle lies in the lack of a comprehensive understanding of defects and their precise effects. This perspective aims to provide insights into defect chemistry for governing HVCs. The classifications, formation mechanisms, and evolution of defects are outlined to explore the intricate relationship between defects and electrochemical behavior. The pressing need for cutting-edge characterization techniques that comprehensively investigate defects across various temporal and spatial scales is emphasized. Building on these fundamental understandings, engineering strategies such as composition tailoring, morphology design, interface modification, and structural control to mitigate or utilize defects are thoroughly discussed for enhanced HVCs performance. Furthermore, these insights are expected to provide vital guidelines for developing high-performance HVCs for next-generation high-energy lithium-ion batteries.

cross-scale characterization↗
DOE OSTI2026

Manipulating Na/TM Ratio‐Driven Structural Heterogeneity of O3‐NaNi 1/3 Fe 1/3 Mn 1/3 O 2 Cathode for High‐Voltage Sodium‐Ion Batteries

The stability of O3-type NaNi 1/3 Fe 1/3 Mn 1/3 O 2 under high-voltage cycling is dictated by how synthesis encodes lattice strain and redox heterogeneity. Here, in this study, the role of Na:TM stoichiometry is systematically resolved by tuning the NaOH:precursor ratio during solid-state synthesis. The stoichiometric condition (Na:TM = 1.00) yields minimized microstrain, enabling uniform O3–P3 phase evolution and homogeneous multi-metal redox with preserved octahedral symmetry. In contrast, Na-excess compositions inherit disordered intermediates and heterogeneous distortion fields that trigger abrupt multiphase transitions and promote localized charge redistribution. In situ XRD captures the divergence in phase-transition pathways, TXM resolves particle-level redox heterogeneity, and XANES corroborates a stronger and more reversible Fe redox contribution at stoichiometry, shifting to diminished Fe participation and spatially inhomogeneous redox at higher Na content. These results establish Na:TM stoichiometry as a critical synthesis parameter controlling both structural coherence and redox stability. Electrochemically, the stoichiometric composition exhibits smooth voltage profiles with minimal polarization growth and retains nearly 80% of its initial capacity after 100 cycles even at an extended 4.2 V cutoff, whereas Na-excess compositions show significantly reduced initial coulombic efficiency and rapid voltage fade. Precise stoichiometric tuning provides a scalable route to defect-suppressed O3 frameworks, enabling structurally resilient, high-voltage sodium-layered cathodes.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Research advances on cobalt-free cathodes for Li-ion batteries - The high voltage LiMn 1.5 Ni 0.5 O 4 as an example

LiMn 1.5 Ni 0.5 O 4 is one of the most promising cathode materials for use in either next generation lithium-ion batteries or all solid-state batteries. However, despite the significant Research and Development (R&D) carried out throughout the last two decades the material has not made serious inroads into market. One of the major reasons is the lack of consistency in the reported intrinsic properties and electrochemical performance owing to major controversies in synthesis, crystal structure and bulk and interfacial properties of LiMn 1.5 Ni 0.5 O 4 , notably in contact with electrolytes. This paper is a compelling review providing an assessment on the mainstream R&D dealing with the various crystal structures of LiMn 1.5 Ni 0.5 O 4 and their evolutions observed during synthesis and cycling in correlation with their electrochemical performance. Influence of electrolytes and additives along with modifications through doping and surface treatments are interrelated, and the electronic and ionic transport properties of the ordered and disordered LiMn 1.5 Ni 0.5 O 4 phases are discussed. Overall, this review provides a detailed assessment on LiMn1.5Ni0.5O4 and the underlying mechanisms governing its electrochemical performance broadly providing a focused framework for further advancement towards commercialization.

25 ENERGY STORAGE↗
DOE OSTI2023

A new high voltage alluaudite sodium battery insertion material

Large-scale stationary storage forms a key sector that can be economically served by sodium-ion batteries. In realizing practical sodium-ion batteries, discovery and development of novel cathodes is essential. In this spirit, alluaudite-type Na 2 Fe 2 (SO 4 ) 3 was reported in 2014 to have the highest Fe 3+ /Fe 2+ redox potential (~3.8 V vs. Na). This finding led to reports on various PO4 3– and SO4 2– based alluaudite compounds exhibiting high energy densities. In 2017, MoO 4 2– based alluaudite, Na 2.67 Mn 1.67 (MoO 4 ) 3 , was found as a 3.45 V cathode material. Exploring molybdenum chemistry further, this work reports alluaudite type Na 3.36 Co 1.32 (MoO 4 ) 3 (NCMo) as a novel versatile electroactive cathode for Li-ion and Na-ion batteries. It was synthesized by a wet solution-combustion route with a restricted annealing duration of 1 min at 600 °C. Calorimetric study revealed the formation enthalpy from component oxides (ΔH° f,ox = –575.49 ± 7.75 kJ/mol) to be highly exothermic. Unlike the sulfate class of alluaudites, this material is highly stable in air and moisture (ΔH ds = 537.42 ± 0.78 kJ/mol). Having an ionic conductivity of 6.065 × 10 –8 S/cm (at 50 °C), it offers a pseudo two-dimensional Na + migration pathway. Without any material optimization, NCMo was found to work as a high-voltage insertion cathode (ca. 4.0 V vs. Na/Na + and 4.1 V vs. Li/Li + ) in sync with theoretically predicted potential of 3.98 V (vs. Na/Na + ). Ex-situ X-ray diffraction and photoelectron spectroscopy studies revealed the occurrence of solid-solution redox mechanism solely involving Co 3+ /Co 2+ redox centre. Finally, it benchmarks Na 3.36 Co 1.32 (MoO 4 ) 3 as a novel electrochemically active Mo-based alluaudite-type polyanionic cathode insertion material.

25 ENERGY STORAGE↗
DOE OSTI2021

Advanced Low‐Flammable Electrolytes for Stable Operation of High‐Voltage Lithium‐Ion Batteries

Abstract Despite being an effective flame retardant, trimethyl phosphate (TMP a ) is generally considered as an unqualified solvent for fabricating electrolytes used in graphite (Gr)‐based lithium‐ion batteries as it readily leads to Gr exfoliation and cell failure. In this work, by adopting the unique solvation structure of localized high‐concentration electrolyte (LHCE) to TMP a and tuning the composition of the solvation sheaths via electrolyte additives, excellent electrochemical performance can be achieved with TMP a ‐based electrolytes in Gr∥LiNi 0.8 Mn 0.1 Co 0.1 O 2 cells. After 500 charge/discharge cycles within the voltage range of 2.5–4.4 V, the batteries containing the TMP a ‐based LHCE with a proper additive can achieve a capacity retention of 85.4 %, being significantly higher than cells using a LiPF 6 ‐organocarbonates baseline electrolyte (75.2 %). Meanwhile, due to the flame retarding effect of TMP a , TMP a ‐based LHCEs exhibit significantly reduced flammability compared with the conventional LiPF 6 ‐organocarbonates electrolyte.

Jia, Hao↗
DOE OSTI2022

Conformal LiF Stabilized Interfaces via Electrochemical Fluorination on High Voltage Spinel Cathodes (≈4.9 V) for Lithium-Ion Batteries

The high voltage LiNi 0.5 Mn 1.5 O 4 (LNMO) spinel is one of the promising cathodes for the lithium-ion batteries due to its high energy densities, good rate performance. However, its high operating potential (≈4.75 V) causes extensive oxidation of conventional carbonate electrolytes, resulting an unstable and thick cathode electrolyte interphase (CEI) layer with a large irreversible capacity and low coulombic efficiency. In this work, we report the formation of thin LiF stabilized interfaces on LNMO via electrochemical fluorination that significantly improves the cycling stability and enhanced the capacity. An electrochemically induced conformal LiF layer acts as a part of a robust CEI by reducing the leakage of electrons and allowing the conduction of Li ions through it. Because of the robust LiF stabilized CEI, LNMO delivers a discharge capacity of ≈148.5 and ≈117.1 mAh g -1 at 0.1 and 1 C rate, respectively. It exhibits excellent cyclability with 80% capacity retention (CR) after 600 cycles in lithium-half cell and ≈90% CR after 200 cycles in full cell with only 0.03% and 0.05% capacity decay per cycle in conventional carbonate electrolytes without additives. Such an excellent electrochemical performance could lead to the potential development of high energy density batteries with high voltage cathodes for grid-based applications.

25 ENERGY STORAGE↗
DOE OSTI2024

A Green, Fire–Retarding Ether Solvent for Sustainable High–Voltage Li–Ion Batteries at Standard Salt Concentration

Lithium-ion batteries (LIBs) are increasingly encouraged to enhance their environmental friendliness and safety while maintaining optimal energy density and cost-effectiveness. Although various electrolytes using greener and safer glyme solvents have been reported, the low charge voltage (usually lower than 4.0 V vs Li/Li + ) restricts the energy density of LIBs. Herein, tetraglyme, a less-toxic, non-volatile, and non-flammable ether solvent, is exploited to build safer and greener LIBs. It is demonstrated that ether electrolytes, at a standard salt concentration (1 m), can be reversibly cycled to 4.5 V vs Li/Li + . Anchored with Boron-rich cathode-electrolyte interphase (CEI) and mitigated current collector corrosion, the LiNi 0.8 Mn 0.1 Co 0.1 O 2 (NMC811) cathode delivers competitive cyclability versus commercial carbonate electrolytes when charged to 4.5 V. Synchrotron spectroscopic and imaging analyses show that the tetraglyme electrolyte can sufficiently suppress the overcharge behavior associated with the high-voltage electrolyte decomposition, which is advantageous over previously reported glyme electrolytes. The new electrolyte also enables minimal transition metal dissolution and deposition. NMC811||hard carbon full cell delivers excellent cycling stability at C/3 with a high average Coulombic efficiency of 99.77%. In conclusion, this work reports an oxidation-resilient tetraglyme electrolyte with record-high 4.5 V stability and enlightens further applications of glyme solvents for sustainable LIBs by designing Boron-rich interphases.

36 MATERIALS SCIENCE↗
NASA NTRS2013

Human-rated Safety Certification of a High Voltage Robonaut Lithium-ion Battery

NASA's rigorous certification process is being followed for the R2 high voltage battery program for use of R2 on International Space Station (ISS). Rigorous development testing at appropriate levels to credible off-nominal conditions and review of test data led to design improvements for safety at the virtual cell, cartridge and battery levels. Tests were carried out at all levels to confirm that both hardware and software controls work. Stringent flight acceptance testing of the flight battery will be completed before launch for mission use on ISS.

Jeevarajan, Judith↗
DOE OSTI2024

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↗
DOE OSTI2021

Stabilizing electrode–electrolyte interfaces to realize high-voltage Li||LiCoO 2 batteries by a sulfonamide-based electrolyte

High-voltage lithium-metal batteries (LMBs) with LiCoO 2 (LCO) as the cathode have high volumetric and gravimetric energy densities. However, it remains a challenge for stable cycling of LCO >4.5 V Li . Here we demonstrate that a rationally designed sulfonamide-based electrolyte can greatly improve the cycling stability at high voltages up to 4.7 V Li by stabilizing the electrode–electrolyte interfaces (EEIs) on both the Li-metal anode (LMA) and high-voltage LCO cathode. With the sulfonamide-based electrolyte, commercial LCO cathodes retain 89% and 85% of their capacities after 200 and 100 cycles under high charging voltages of 4.55 V Li and 4.6 V Li , respectively, significantly outperforming traditional carbonate-based electrolytes. The surface degradation, impedance growth, and detrimental side reactions in terms of gas evolution and Co dissolution are well suppressed. Our work demonstrates a promising strategy for designing new electrolytes to realize high-energy Li||LCO batteries.

25 ENERGY STORAGE↗
DOE OSTI2024

Acidity-Governed Rules in the Electrochemical Performance of Fluorinated Benzenes for High-Voltage Lithium Metal Batteries

Judicious selection of the optimal fluorobenzene (FB) as a nonsolvating cosolvent for lithium metal batteries (LMBs) is reported. For this work, we found the key correlation between FB structures and cycling stabilities of cells: increased fluorine substitution of FBs results in higher anodic stability but at the expense of reduced reductive stability, and FBs containing three or more fluorine atoms exhibit insufficient anodic stability in the electrolyte system comprised of fluoroethylene carbonate (FEC) and ethyl methyl carbonate (EMC). More importantly, FBs with higher acidity (lower pK a ) due to protons located between two adjacent fluorine atoms tend to be more susceptible to side reactions during cycling. Our results indicate that difluorobenzenes with no “acidic” proton (DFB2 and DFB4) have emerged as the optimal choice with the desired redox stability in high-voltage LMBs. Nuclear magnetic resonance and X-ray photoelectron spectroscopy confirmed these findings, providing guidance for selecting the most suitable FB variants as nonsolvating cosolvents for high-voltage LMBs.

25 ENERGY STORAGE↗
DOE OSTI2022

Design of a Scavenging Pyrrole Additive for High Voltage Lithium-Ion Batteries

We report 1-(dimethylamino) pyrrole (PyDMA) as an electrolyte additive for high voltage lithium-ion batteries based on LiNi 0.6 Mn 0.2 Co 0.2 O 2 (NMC622)//Graphite with an upper cutoff voltage of 4.4 V. Density Functional Theory (DFT) modeling indicates that the unique structure of PyDMA could be effective in preventing the hydrolysis of LiPF 6 in a carbonate electrolyte, mitigating issues related to HF formation. The calculations also indicated that the additive would oxidize at lower potentials than typical electrolyte solvents, which could lead to protective films at the cathode surface. These expectations were tested using Nuclear Magnetic Resonance (NMR) and extensive electrochemical characterization. NMR studies confirmed the superb dehydrating capability of PyDMA, which successfully prevents HF formation even at high water content. Addition of 0.5 wt% PyDMA resulted in improved capacity retention in full-cells, and also in lower levels of transition metal dissolution from the cathode. Incremental capacity (dQ/dV) analysis indicates that benefits of PyDMA at low concentration (0.5–1 wt%) are associated with decreased rates of Li + -trapping reactions, and that higher concentrations of the additive can lead to isolation of cathode domains. Furthermore, our study indicates that PyDMA could be a promising electrolyte additive for high voltage lithium-ion batteries at a low concentration.

25 ENERGY STORAGE↗
DOE OSTI2021

Electrolytes Polymerization‐Induced Cathode‐Electrolyte‐Interphase for High Voltage Lithium‐Ion Batteries

Abstract Lithium‐ion batteries (LIBs) based on LiNi x Co y Mn 1‐x‐y O 2 (NCM) cathode materials have been widely commercialized, because of their high energy density, favorable rate performance, and relatively low cost. However, with increased Ni content to further increase their energy density, their cycling stability deteriorates dramatically and thus fails to meet the commercial application requirements. The artificial cathode‐electrolyte‐interphase (CEI) is a promising approach to solve this problem. Here, a robust CEI is fabricated through in situ polymerization of ethylene carbonate induced by aluminum isopropoxide (AIP). By adding 1 wt.% AIP in a commercial electrolyte, the capacity retention of LiNi 0.8 Co 0.1 Mn 0.1 O 2 ||Li cell at 1 C rate has been significantly increased from 80.8% to 97.8% with a highly reversible capacity of 176 mA h g −1 after 200 cycles. AIP can be also used as an additive during the slurry‐making process, enabling a reversible capacity of 170 mA h g −1 for LiCoO 2 after 200 cycles even at a high charge cut‐off voltage of 4.6 V. It is confirmed that the in situ formed CEI layer can prevent the cathodes from cracking and reduce the irreversible phase transformation.

Yang, Jixiang↗