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Amine, Rachid

Publications and source records attributed to Amine, Rachid.

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Nanoengineering of non-aqueous liquid electrolyte solutions for future lithium metal batteries

Research and development of non-aqueous electrolyte solutions are essential for practical advancement towards the production of high-energy lithium metal batteries (LMBs). An ideal LMB electrolyte solution should enable highly efficient, uniform and prolonged lithium metal plating and stripping, preserve the electrodes’ electro(chemo)mechanical properties and ensure compatibility with all cell components. However, despite extensive research efforts, scientists have yet to achieve an electrolyte design that meets these requirements simultaneously. Here, by examining the nanoengineering aspects of various non-aqueous electrolyte solution designs, we elucidate the understanding of the nanoscale physicochemical and electrochemical processes taking place in LMBs, which are mainly governed by the thermodynamic and kinetic properties of the electrolyte system. We also explore emerging research directions and propose an accelerated, iterative framework that integrates nanoengineering principles with machine learning, high-throughput computation and experimentation to facilitate the development of next-generation non-aqueous electrolyte solutions for practical LMBs.

Weintz, Dominik↗
DOE OSTI2024

Ultrastable cathodes enabled by compositional and structural dual-gradient design

Cathodes for next-generation batteries are pressed for higher voltage operation (≥4.5 V) to achieve high capacity with long cyclability and thermal tolerance. Current cathodes fail to meet these requirements owing to structural and electrochemical strains at high voltages, leading to fast capacity fading. Here, in this work, we present a cathode with a coherent architecture ranging from ordered to disordered frameworks with concentration gradient and controllable Ni oxidation activities, which can overcome voltage ceilings imposed by existing cathodes. This design enables simultaneous high-capacity and high-voltage operation at 4.5 V without capacity fading, and up to 4.7 V with negligible capacity decay. Multiscale diffraction and imaging techniques reveal the disordered surface is electrochemically and structurally indestructible, preventing surface parasitic reactions and phase transitions. Structural coherence from ordering to disordering limits lattice parameter changes, mitigating lattice strain and enhancing morphological integrity. The dual-gradient design also notably improves thermal stability, driving the advancement of high-performance cathode materials.

36 MATERIALS SCIENCE↗
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 OSTI2024

Beyond conventional batteries: a review on semi-solid and redox targeting flow batteries-LiFePO{sub 4} as a case study.

Clean and sustainable energy is becoming increasingly crucial to tackle the current energy crisis. However, the intermittent nature of renewable energy sources presents a challenge for their effective implementation. Redox flow batteries (RFBs) have emerged as a promising solution to this problem, as they can help enhance the stability of grid networks and promote the use of renewable energy sources. RFBs are highly modular and scalable systems that can be customized to meet the power and energy requirements of different renewable energy plants. Moreover, they offer several advantages over conventional battery technologies, including cost and safety concerns. However, conventional RFBs have limited energy densities due to the low solubility of their active species in electrolyte. To overcome this limitation, semi-solid (SSRFBs) and redox targeting (RTFBs) flow batteries have been proposed. These systems feature high concentrations of active species and impressive energy densities, making them highly attractive for renewable energy applications. LiFePO4 (LFP) is a highly promising active material for semi-solid and targeting flow batteries. One of the key advantages of LFP is its low raw materials cost, as it is composed of Earth-abundant elements such as iron and phosphorus. This makes it an attractive option for large-scale battery production. The recent developments in SSRFBs and RTFBs using LFP as catholyte hold great promise for the future of sustainable energy storage. The combination of LFP's low cost, safety, durability, and high energy density with the modularity and scalability of flow battery systems make for a compelling solution to the challenges of intermittent renewable energy sources. Ongoing research and development in this area will likely yield even further improvements in the performance and efficiency of LFP-based flow batteries, opening exciting new possibilities for sustainable energy storage.

El Halya, Nabil↗
DOE OSTI2024

Unrecoverable lattice rotation governs structural degradation of single-crystalline cathodes

Transitioning from polycrystalline to single-crystalline nickel-rich cathodes has garnered considerable attention in both academia and industry, driven by advantages of high tap density and enhanced mechanical properties. However, cathodes with high nickel content (>70%) suffer from substantial capacity degradation, which poses a challenge to their commercial viability. Here, leveraging multiscale spatial resolution diffraction and imaging techniques, we observe that lattice rotations occur universally in single-crystalline cathodes and play a pivotal role in the structure degradation. These lattice rotations prove unrecoverable and govern the accumulation of adverse lattice distortions over repeated cycles, contributing to structural and mechanical degradation and fast capacity fade. These findings bridge the previous knowledge gap that exists in the mechanistic link between fast performance failure and atomic-scale structure degradation.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Improved cycle stability and high-rate capability of LiNbO 3 -coated Li 3 VO 4 as anode material for lithium-ion battery

Lithium vanadate (Li 3 VO 4 ) has garnered considerable attention as an alternative negative electrode material for non-aqueous lithium-ion batteries due to its high capacity, energy efficiency, and stable discharge voltage. Nonetheless, the Li 3 VO 4 material displays a low rate capability, attributed mainly to its poor intrinsic electronic conductivity. Here, in this study, we report the synthesis of lithium niobate LiNbO 3 -coated Li 3 VO 4 (LVO@LNO) using a one-pot sol-gel method. The resulting LVO@LNO demonstrates a high reversible capacity of approximately 530 mAh/g, which is more than double that of free Li 3 VO 4 . To explore the effect of the LNO coating process on the morphological and structural properties, Raman, XRD, operando XRD, XPS, SEM and HTEM analyses were conducted. To explain the enhancement of electronic conductivity in our modified material after a LiNbO 3 coating, we conducted an Ex-Situ electrochemical impedance (EIS) and Density Functional Theory (DFT) computational study. Additionally, we designed a full cell utilizing a 1 wt% LNO-coated LVO anode and NMC-811 cathode. The cell yielded an output voltage of approximately 2.8 V with a high initial specific capacity of 350 mAh/g versus to the anode, at 1C with a capacity retention of 85 % after 100 cycles.

25 ENERGY STORAGE↗
DOE OSTI2024

Template Assisted Lithium Superoxide Growth for Lithium-Oxygen Batteries

Developing batteries with energy densities comparable to internal combustion technology is essential for a worldwide transition to electrified transportation. Li-O2 batteries are seen as the ‘holy grail’ of battery technologies since they have the highest theoretical energy density of all battery technologies. Current lithium-oxygen (Li-O2) batteries suffer from large charge overpotentials related to electronic resistivity of the insulating lithium peroxide (Li2O2) discharge product. One potential solution is the formation and stabilization of a lithium superoxide (LiO2) discharge intermediate that exhibits good electronic conductivity. However, LiO2 is reported to be unstable at ambient temperature despite its favorable formation energy at -1.0 eV/atom. In this paper, based on our recent work on the development of cathode materials for aprotic lithium oxygen batteries including two intermetallic compounds, LiIr3 and LiIr, that are found to form good template interfaces with LiO2, a simple goodness of fit R factor to gauge how well a template surface structure can support LiO2 growth is developed. The R factor is a quantitative measurement to calculate the geometric difference in the unit cells of specific Miller Index 2D planes of the template surface and LiO2. Using this as a guide, the R factors for LiIr3, LiIr, and La2NiO4+, are found to be good. This guide is attested by simple extension to other noble metal intermetallics with electrochemical cycling data including LiRh3, LiRh, and Li2Pd. Finally, the template concept is extended to main group elements and the R factors for LiO2 (111) and Li2Ca suggest that Li2Ca is a possible candidate for the template assisted LiO2 growth strategy.

Intermetallics↗
DOE OSTI2023

Biopolymer‐assisted Synthesis of P‐doped TiO 2 Nanoparticles for High‐performance Lithium‐ion Batteries: A Comprehensive Study

Abstract TiO 2 material has gained significant attention for large‐scale energy storage due to its abundant, low‐cost, and environmentally friendly properties, as well as the availability of various nanostructures. Phosphorus doping has been established as an effective technique for improving electronic conductivity and managing the slow ionic diffusion kinetics of TiO 2 . In this study, non‐doped and phosphorus doped TiO 2 materials were synthesized using sodium alginate biopolymer as chelating agent. The prepared materials were evaluated as anode materials for lithium‐ion batteries (LIBs). The electrodes exhibit remarkable electrochemical performance, including a high reversible capacity of 235 mAh g −1 at 0.1 C and excellent first coulombic efficiency of 99 %. An integrated approach, combining operando XRD and ex‐situ XAS, comprehensively investigates the relationship between phosphorus doping, material structure, and electrochemical performance, reinforced by analytical tools and first principles calculations. Furthermore, a full cell was designed using 2 %P‐doped TiO 2 anode and LiFePO 4 cathode. The output voltage was about 1.6 V with high initial specific capacity of 148 mAh g −1 , high rate‐capability of 120 mAh g −1 at 1 C, and high‐capacity retention of 96 % after 1000 cycles at 1 C.

El Halya, Nabil↗
DOE OSTI2023

In situ microscopy and spectroscopy characterization of microsized Sn anode for sodium-ion batteries

Microsized Sn is a promising anode material for sodium-ion batteries in terms of cost, specific capacity, and volumetric energy density, which however suffers from huge volume changes and rapid cell degradation upon cycling. Despite recent advances via nanostructured electrode design and interface engineering, the correlation between mechanical stability, solid-electrolyte interphase (SEI) and reaction kinetics/reversibility remains controversial and elusive. Here, in this work, by combining in situ scanning electron microcopy and X-ray absorption spectroscopy as well as X-ray photoelectron spectroscopy, we have investigated the underlying electro-chemo-mechanical behavior and their coupling effects during charge/discharge of microsized Sn anode. Our results revealed that microsized Sn is pulverized into nanoparticles with simultaneous formation of numerous voids and pores upon the 1st charge/discharge, while the electrolytes composition plays a critical role on the consequent parasitic reactions and eventually the sodiation/de-sodiation reversibility. In contrast to carbonate-based electrolytes, ether-based electrolytes enabled formation of inorganic species dominated SEI with improved mechanical strength, thus leading to higher specific capacity and improved cycling stability. The present findings are crucial for future development of microsized anode materials for rechargeable batteries with high volumetric energy density.

25 ENERGY STORAGE↗
DOE OSTI2023

Triarylmethyl cation redox mediators enhance Li–O 2 battery discharge capacities

A major impediment to Li–O 2 battery commercialization is the low discharge capacities resulting from electronically insulating Li 2 O 2 film growth on carbon electrodes. Redox mediation offers an effective strategy to drive oxygen chemistry into solution, avoiding surface-mediated Li 2 O 2 film growth and extending discharge lifetimes. As such, the exploration of diverse redox mediator classes can aid the development of molecular design criteria. Here, in this work, we report a class of triarylmethyl cations that are effective at enhancing discharge capacities up to 35-fold. Surprisingly, we observe that redox mediators with more positive reduction potentials lead to larger discharge capacities because of their improved ability to suppress the surface-mediated reduction pathway. This result provides important structure–property relationships for future improvements in redox-mediated O 2 /Li 2 O 2 discharge capacities. Furthermore, we applied a chronopotentiometry model to investigate the zones of redox mediator standard reduction potentials and the concentrations needed to achieve efficient redox mediation at a given current density. We expect this analysis to guide future redox mediator exploration.

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

Prelithiation of Lithium Peroxide for Silicon Anode: Achieving a High Activation Rate

The use of lithium peroxide (Li2O2) as a cost-effective low-weight prelithiation cathode additive was successfully demonstrated. Through a series of studies on the chemical stability of Li2O2 and the activation process of Li2O2 on the cathode, we revealed that Li2O2 is more compatible with conventional electrolyte and cathode laminate slurry than lithium oxide. Due to the significantlysmaller size of commercial Li2O2, it can beused directly as a cathode additive. Moreover, the activation of Li2O2 on the cathode leads to the impedance growthof the cathode possibly resulting from the release of dioxygen andevacuation of Li2O2 inside the cathode. Withthe introduction of a new Li2O2 spread-coatingtechnique on the cathode, the capacity loss was suppressed. Si||NMCfull cells using Li2O2 spread-coated cathodedemonstrated a highly promising activation rate of Li2O2 and significantly enhanced specific capacity and cyclingstability compared to the uncoated full cells.

cathode additive↗
DOE OSTI2023

Terminally fluorinated glycol ether electrolyte for lithium metal batteries

Despite being an excellent candidate for lithium metal batteries due to its stability towards lithium metal, ethereal solvent suffers from relatively low anodic stability, rendering it incompatible with high voltage cathode. Although the anodic stability of ethereal solvent can be enhanced by fluorination, the lithium solvating ability of fluorinated ethers is largely reduced. As a result, common hydrofluoroethers, such as 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether (TTE) and bis(2,2,2-trifluoroethyl) ether (BTFE) are not able to dissolve any lithium salt, albeit enhanced oxidation potential. Therefore, new fluorinated glycol ethers were synthesized in this research. The diglyme analog, which was terminally fluorinated, demonstrated high anodic stability and excellent capability to facilitate lithium plating/stripping. Unlike its non-fluorinated counterpart, the fluorinated diglyme analog displayed outstanding compatibility with lithium hexafluorophosphate, which is an essential salt in lithium-ion batteries. Here it was shown that the electrolyte based on fluorinated diglyme analog with fluoroethylene carbonate as co-solvent enabled highly stable cycling of Li-metal batteries pairing with layered oxide cathode.

25 ENERGY STORAGE↗
DOE OSTI2023

Patterned anode for lithium-ion batteries

Anodic materials for lithium ions batteries include a current collector and a superlattice disposed on at least a portion of the current collector, the superlattice comprising: alternating layers of an anode active material and an anode inactive material; and a plurality of channels that extend from the current collector through the alternating layers of anode active material and anode inactive material.

Chen, Zonghai↗
DOE OSTI2023

A room temperature rechargeable Li 2 O-based lithium-air battery enabled by a solid electrolyte

Lithium-air batteries have scope to compete with gasoline in terms of energy density. However, in most systems, the reaction pathways either involve one- or two-electron transfer, leading to lithium peroxide (Li 2 O 2 ) or lithium superoxide (LiO 2 ), respectively. Kondori et al. investigated a lithium-air battery that uses a ceramic-polyethylene oxide–based composite solid electrolyte and found that it can undergo a four-electron redox reaction through lithium oxide (Li 2 O) formation and decomposition (see the Perspective by Dong and Lu). The composite electrolyte embedded with Li 10 GeP 2 S 12 nanoparticles shows high ionic conductivity and stability and high cycle stability through a four-electron transfer process.

25 ENERGY STORAGE↗
DOE OSTI2022

LiNi 0.8 Fe 0.1 Al 0.1 O 2 as a Cobalt-Free Cathode Material with High Capacity and High Capability for Lithium-Ion Batteries

Obtaining cathode materials with high capacity and cycle stability is one of the main challenges regarding the success of electric vehicle technologies. However, most of the widely used materials with these properties involve the use of toxic and expensive cobalt as the active material. To overcome this challenge, this work proposes a novel cobalt-free cathode material, synthesized for the first time using a solid-state reaction, whose general formula is LiNi 0.8 Fe 0.1 Al 0.1 O 2 (NFA). This class of materials offers high capacity and reduces the battery costs by removing cobalt, without jeopardizing the structural stability and safety of the NFAs. The morphology and the structural properties of the obtained NFA cathode material were characterized using different techniques, e.g., scanning electronic microscopy, X-ray diffraction, X-ray fluorescence, and infrared and Raman spectroscopies. The electrochemical activity and diffusivity of the Li-ion during lithium removal and its insertion into the bulk of the NFA cathode demonstrated high-yield specific capacities of ≈180 mAh g –1 at 0.1C, along with a reasonable rate capability and cycling stability, with a capacity retention of ≈99.6% after 100 charge/discharge cycles at a rate of C/2, and whose operando X-ray diffraction experiments have been used to study the crystallographic transitions during the lithiation–delithiation reaction.

25 ENERGY STORAGE↗
DOE OSTI2022

A New Cathode Material for a Li–O 2 Battery Based on Lithium Superoxide

Li–O 2 batteries suffer from large charge overpotentials due to the high charge transfer resistance of Li 2 O 2 discharge products. A potential solution to this problem is the development of LiO 2 -based batteries that possess low charge overpotentials due to the lower charge transfer resistance of LiO 2 . In this report, IrLi nanoparticles were synthesized and implemented for the first time as a LiO 2 battery cathode material. The IrLi nanoparticle synthesis was achieved by a temperature- and time-optimized thermal reaction between a precise ratio of iridium nanoparticles and lithium metal. Li–O 2 batteries employing the IrLi-rGO cathodes were cycled up to 100 cycles at moderate current densities with sustained low cell charge potentials (<3.5 V). Further, various characterization techniques, including SEM, DEMS, TEM, Raman, and titration, were used to demonstrate the LiO 2 discharge product and the absence of Li 2 O 2 . On the basis of first-principles calculations, it was concluded that the formation of crystalline LiO 2 can be stabilized by epitaxial growth on the (111) facets of IrLi nanoparticles present on the cathode surface. These findings demonstrate that, in addition to the previously studied Ir 3 Li intermetallic, the IrLi intermetallic also provides a means by which LiO 2 discharge products can be stabilized and confirms the importance of templating for the formation process.

25 ENERGY STORAGE↗
DOE OSTI2022

Tuning working potential of silicon-phosphorus anode via microstructure control for high-energy lithium-ion batteries

The primary research on anode materials of lithium-ion batteries have been focused on increasing the specific capacity, while the working potential that is also closely related to the practical energy density of batteries has been paid much less attention. In this paper, starting from micrometer-sized silicon and black phosphorus, we have reported a high-energy silicon-phosphorus/carbon anode (denoted as mSPC) via a high-energy ball milling process, which demonstrates an average discharge working potential of 0.3 volts versus lithium, together with a high reversible capacity of > 2000 mAh/g, high initial coulombic efficiency of 84%, excellent cycle stability, and superior rate capability up to 15 A/g. Furthermore, in situ focused-ion-beam scanning electron microscopy reveals that the volume change of the mSPC anode during repeated (de) lithiation is effectively alleviated. In contrast, starting from nanometer-sized silicon, the resulted anode (denoted as nSPC) not only presents a lower reversible capacity (~1200 mAh/g), but also exhibits a higher charge/discharge working potential, leading to reduced energy density. Our results indicate the importance of composition/structure control in tailoring the working potential and specific capacity of alloying-type anodes towards high-energy lithium-ion batteries.

25 ENERGY STORAGE↗