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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 19 records
All sourcesNASA NTRSDOE OSTI
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↗
NASA NTRS2004

Observation of Dust Stream Formation Produced by Low Current, High Voltage Cathode Spots

Macro-particle acceleration driven by low current, high voltage cathode spots has been investigated. The phenomenon was observed to occur when nanometer and micrometer-sized particles in the presence of a discharge plasma were exposed to a high voltage pulse. The negative voltage pulse initiates the formation of multiple, high voltage, low current cathode spots which provides the mechanism of actual acceleration of the charged dust particles. Dust streams generated by this process were detected using laser scattering techniques. The particle impact craters observed at the surface of downstream witness badges were documented using SEM and light microscopy.

Foster, John E.↗
DOE OSTI2022

Hydrogen bonds enhanced composite polymer electrolyte for high-voltage cathode of solid-state lithium battery

Polymer electrolyte is one of the important components for developing advanced solid-state lithium batteries (SSLBs). However, the narrow electrochemical stability window restricts the practical application with high-voltage cathodes. In this study, a series of composite solid electrolytes (CSEs), possessing both wide electrochemical stability window (up to 5.0 V vs. Li + /Li) and high ionic conductivity (over 1.35×10 -3 S/cm at 25 °C), were reported by integrating SiO 2 nanoparticles into poly(vinyl ethylene carbonate) polymer electrolyte. The enhanced anti-oxidation performances are mainly caused and confirmed by the local intermolecular interactions of hydrogen bonds in CSE. Based on this CSE, the SSLBs with LiCoO 2 cathode present good cycle stability at high voltage, and the capacity retention with 4.5 V cut-off voltage is about 94% after 200 cycles. This work not only proves the importance of intermolecular interactions in CSE, but also provides an effective method for achieving high-energy SSLBs with enhanced interface compatibility between polymer electrolyte and highvoltage cathodes

25 ENERGY STORAGE↗
DOE OSTI2024

Lattice engineering of high-entropy olivine-type lithium metal phosphate as high-voltage cathodes

Engineering of high-entropy cathode materials for lithium-ion batteries has been actively pursued owing to the outstanding conductivity of high-entropy materials benefited from the maximum entropy and unique antisite disordering structure. Olivine lithium metal phosphates such as LiMnPO 4 and LiNiPO 4 feature high working voltages but low capacities due to their insulation nature. Here in this work, the synthesis of the high-entropy lithium metal phosphate materials (HELMPs) is realized by combining mechanochemistry with a calcination method. By regulating lattice of HELMPs, the high-entropy Li(Mn 0.35 Fe 0.35 Co0.1Mg 0.1 Ca 0.1 )PO 4 reveals three typical high-voltage plateaus in charge–discharge curves corresponding to the redox of Fe, Mn, and Co in the voltage range of 2.0–4.9 V vs Li + /Li, and a much higher initial capacity than LiMnPO 4 (104 vs 15 mAh g -1 ).

25 ENERGY STORAGE↗
DOE OSTI2022

Different interfacial reactivity of lithium metal chloride electrolytes with high voltage cathodes determines solid-state battery performance

A deep understanding of the interaction of the surface of cathode materials with solid electrolytes is crucial to design advanced solid-state batteries (SSBs). This is especially true for the new class of lithium metal chloride (Li-M-Cl) solid electrolytes which are receiving rapidly growing attention due to their very high oxidative stability (>4 V) in combination with good ionic conductivity that can enable long cell cycle life. While Li-M-Cl electrolytes typically contain resource-limited metals (M) such as indium or rare earths, work has focused on substituting M with more abundant elements such as zirconium. Via operando resistance measurements using intermittent current interruption we explore the dynamic evolution of the interphase at the surface of Ni-rich NCM85 or NCM111 cathode particles inside a working SSB with three different Li-(M 1 ,M 2 )-Cl catholytes (Li 3 InCl 6 , Li 2 Sc 1/3 In 1/3 Cl 4 and Li 5/2 Y 1/2 Zr 1/2 Cl 6 ) to reveal the impact of the cationic metal substitution on the interfacial chemistry. We show that the metal plays a critical role in determining high voltage stability, contrary to prior assumptions. Using a combination of cyclic voltammetry and ultraviolet photoelectron spectroscopy measurements of the electronic band structure to assess oxidative stability; coupled with DFT calculations and ToF-SIMS to evaluate products formed at the interface at different upper cutoff potentials and degrees of delithiation, we are able to differentiate between electrochemical and chemical degradation. We find that Li 2 Sc 1/3 In 1/3 Cl 4 yields the highest (and Li 3 InCl 6 the lowest) stability against electrochemical oxidation, while Li 5/2 Y 1/2 Zr 1/2 Cl 6 undergoes a detrimental chemical reaction with oxygen released from Ni-rich NCM85 at high potentials, resulting in fast capacity fading. Altogether, our work establishes a platform for the metrics and an approach that can be utilized to efficiently evaluate the stability of new halide SEs in SSB cells.

25 ENERGY STORAGE↗
DOE OSTI2025

Toward High-Voltage Cathodes for Zinc-Ion Batteries: Discovery Pipeline and Material Design Rules

Efficient energy storage systems are crucial to address the intermittency of renewable energy sources. As multivalent batteries, Zn-ion batteries (ZIBs), while inherently low voltage, offer a promising low-cost alternative to Li-ion batteries due to the viable use of zinc as the anode. However, to maximize the potential impact of ZIBs, rechargeable cathodes with improved Zn diffusion are needed. To better understand the chemical and structural factors influencing Zn-ion mobility within battery electrode materials, we employ a high-throughput computational screening approach to systematically evaluate candidate intercalation hosts for ZIB cathodes, expanding the chemical search space on empty intercalation hosts that do not contain Zn. We leverage a high-throughput screening funnel to identify promising cathodes in ZIBs, integrating screening criteria with density functional theory (DFT)-based calculations of Zn2+ intercalation and diffusion inside the host materials. Using these data, we identify the design principles that favor Zn-ion mobility in candidate cathode materials. Building on previous work on divalent-ion cathodes, this study broadens the chemical space for next-generation multivalent energy storage systems.

electrodes↗
DOE OSTI2020

Stabilized Electrode/Electrolyte Interphase by a Saturated Ionic Liquid Electrolyte for High-Voltage NMC532/Si-Graphite Cells

Nonaqueous electrolyte has become one of the technical barriers in enabling Li-ion battery comprising of a high voltage cathode and high capacity anode. Here, we demonstrate a saturated piperidinum bis(fluorosulfonyl)imide ionic liquid (IL) with a LiFSI salt not only supports the redox reaction on the cathode at high voltages, but also shows exceptional kinetic stability on the lithiated anode as evidenced by its improved cycling performance in a NMC532/Si-graphite full cells cycled between 4.6 and 3.0 V. On the basis of the spectroscopic/microscopic analysis and molecular dynamics (MD) simulations, the superior performance of the cells is attributed to the formation of solid-electrolyte-interphase on both electrode as well as unique solvation structure where a deadlocked coordination network is established at the saturated state, which prevents transition metal dissolution into the electrolyte via a solvation process.

25 ENERGY STORAGE↗
DOE OSTI2021

Toward the Development of a High-Voltage Mg Cathode Using a Chromium Sulfide Host

Development of Mg-ion batteries as advanced electrochemical energy storage systems relies on the design and discovery of high-voltage positive electrode (cathode) materials. To date, a variety of sulfide cathodes have been reported (e.g., Mg x Mo 6 S 8 , Mg x Ti 2 S4, etc.), but the voltages of these materials are too low to prepare a high energy density Mg cell. Theoretical computations predicted that Mg x Cr 2 S 4 operating with the high-voltage Cr 3+/4+ redox couple would serve as a suitable cathode candidate, but experimental attempts to extract Mg 2+ from the lattice have been largely unsuccessful. Here, we show that reversible electrochemical activity within a thiospinel framework (AB 2 S 4 ) relies on a redox-active transition metal present in the B site; otherwise, anionic redox activity triggers decomposition of the spinel structure. Since Cr and S states are highly coupled in MgCr 2 S 4 , the Cr 3+/4+ redox couple is inaccessible so that reversible (de)intercalation of Mg 2+ cannot occur and charging leads to dissolution of the active material. These findings point to an insufficiency in the screening criteria previously used to identify MgCr 2 S 4 as a promising Mg cathode. Thus, a computable descriptor based on the electronic structure of the discharged material is proposed to predict the prevalence of cation vs anion redox and improve future surveys of potential candidates. It is unlikely that the high-voltage Cr redox couple will be accessible to oxidation in the presence of sulfur within the restrictions of a spinel framework; however, it is possible that a suitable layered Mg x CrS 2 structure could serve as a reversible high-voltage Mg cathode.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

P2-Type Moisture-Stable and High-Voltage-Tolerable Cathodes for High-Energy and Long-Life Sodium-Ion Batteries

P2-Na 0.67 Ni 0.33 Mn 0.67 O 2 represents a promising cathode for Na-ion batteries, but it suffers from severe structural degradation upon storing in a humid atmosphere and cycling at a high cutoff voltage. Here we propose an in situ construction to achieve simultaneous material synthesis and Mg/Sn cosubstitution of Na 0.67 Ni 0.33 Mn 0.67 O 2 via one-pot solid-state sintering. Here, the materials exhibit superior structural reversibility and moisture insensitivity. In-operando XRD reveals an essential correlation between cycling stability and phase reversibility, whereas Mg substitution suppressed the P2–O2 phase transition by forming a new Z phase, and Mg/Sn cosubstitution enhanced the P2–Z transition reversibility benefiting from strong Sn–O bonds. DFT calculations disclosed high chemical tolerance to moisture, as the adsorption energy to H 2 O was lower than that of the pure Na 0.67 Ni 0.33 Mn 0.67 O 2 . A representative Na 0.67 Ni 0.23 Mg 0.1 Mn 0.65 Sn 0.02 O 2 cathode exhibits high reversible capacities of 123 mAh g –1 (10 mA g –1 ), 110 mAh g –1 (200 mA g –1 ), and 100 mAh g –1 (500 mA g –1 ) and a high capacity retention of 80% (500 mA g –1 , 500 cycles).

25 ENERGY STORAGE↗
DOE OSTI2022

Origin and regulation of oxygen redox instability in high-voltage battery cathodes

Oxygen redox at high-voltage has emerged as a transformative paradigm for high-energy battery cathodes such as layered transition-metal oxides by offering extra capacity beyond conventional transition-metal redox. However, these cathodes suffer from voltage hysteresis, voltage fade, and capacity drop upon cycling; single-crystalline cathodes have recently shown some improvements but these challenges still remain. We reveal the fundamental origin of oxygen redox instability to be originated from the domain boundaries that are present in single-crystalline cathode particles. By synthesizing single-crystalline cathodes free of domain boundaries, we show that the elimination of domain boundaries enhances the reversible lattice oxygen redox while inhibiting the irreversible oxygen release. Further, this leads to significantly suppressed structural degradation and improved mechanical integrity during battery cycling and abuse heating. The robust oxygen redox enabled through domain boundary control provides practical opportunities towards high-energy, long-cycling, and safe batteries.

25 ENERGY STORAGE↗
DOE OSTI2025

Demonstration of MgCr 2– x Mn x O 4 Spinel Oxide Cathodes in High-Voltage Mg Batteries

Solid-solution oxide spinels with high redox voltages and facile Mg 2+ mobility have been identified as promising candidates for practical, high-voltage cathodes in Mg batteries. In this work, we discuss the development of MgCr 2-x Mn x O 4 [x = 0.5, 1, 1.2] solid-solution spinel oxides as a cathode material and their electrochemical performance paired with an Mg anode in a full cell. This work presents the first demonstration of full cells with these materials. Mg-Cr-Mn spinel oxides with varying Cr and Mn contents were synthesized using alternative synthetic routes for optimal electrochemical performance. High-resolution synchrotron powder X-ray diffraction (PXRD), solid-state nuclear magnetic resonance (NMR) spectroscopy, and electron microscopy showed that these different synthetic routes resulted in changes in structures and particle morphologies, which in turn affect the electrochemical performance. Particularly, the urea coprecipitation synthetic route resulted in high-surface-area particles that enabled lower overpotentials and increased discharge capacity. The high surface area also resulted in expedited structural degradation caused by the irreversible migration of Mg 2+ into normally vacant 16c sites in the spinel lattice. This structural degradation was lessened by using a hydrosauna-urea synthesis method, which decreased the Mg/Mn inversion ratio while retaining high-surface-area particles with good cycling performance. Furthermore, our findings highlight the necessity for high surface area or nanostructured spinel oxide cathodes with minimized Mg-Mn inversion to enable spinel oxide cathodes in Mg full cells.

Mg anode↗