Materials For Li-ion Batteries Research Articles

Citric Acid as a Small Molecule Binder for Si-Based Li-Ion Battery Anode Materials

Abstract In this study, citric acid (CA) dissolved in propylene glycol (PG) was shown to be an effective binder/solvent system for Si-based anode materials in Li-ion batteries. In this system, PG serves both as a slurry solvent and provides viscosity to the slurry to inhibit the settling of active particles and for proper rheology during the coating process, while the small CA molecule serves as a binder/artificial solid electrolyte interphase. After 50 cycles, SiO/carbon black/CA electrodes had a higher capacity retention (93%) than conventional electrodes with lithium polyacrylate (LiPAA) polymeric binder (68%), due to superior maintenance of cohesion with active particles. This demonstrates that small molecules may be used as effective binders for Si-based anode materials when a slurry solvent is used that can take on the role of maintaining the slurry rheology.

Long-range ordered porous carbon C52: A high-performance anode metallic material for next-generation Li-ion batteries with extremely high capacity

Long-range ordered porous carbon C52: A high-performance anode metallic material for next-generation Li-ion batteries with extremely high capacity

Lithium-magnesium alloy as anode materials for Li-ion batteries: A first-principles calculation

Lithium-magnesium alloy as anode materials for Li-ion batteries: A first-principles calculation

Monolayered π-d conjugated metal-2,3,5,6-tetraamino-1,4-benzoquinone coordination polymers as potential cathode materials for Li-ion batteries

Monolayered π-d conjugated metal-2,3,5,6-tetraamino-1,4-benzoquinone coordination polymers as potential cathode materials for Li-ion batteries

Zinc-substituted Li4Ti5O12 as a novel large-capacity and low-voltage titanium-based anode material for Li-ion batteries

Zinc-substituted Li4Ti5O12 as a novel large-capacity and low-voltage titanium-based anode material for Li-ion batteries

Quantifying the local laser induced heating of carbon-coated Li-ion battery materials during Raman spectroscopy

Quantifying the local laser induced heating of carbon-coated Li-ion battery materials during Raman spectroscopy

Selective lithium recovery from spent NCM type Li-ion battery materials by powder electrolysis

Selective lithium recovery from spent NCM type Li-ion battery materials by powder electrolysis

Inhibition of manganese ion migration and dissolution by selective ions sieving effect of MOF-based solid electrolytes.

Lithium manganese oxide (LiMn2O4) is a promising cathode material for Li-ion batteries due to its abundant reserves and high discharge voltage. However, the dissolution and migration of transition metal Mn ions during the cycling process will cause a significant deterioration of capacity. In this study, a MOF-based quasi-solid electrolyte (UiO-QSE) is proposed to tackle this issue. The large specific surface area and open metal sites of UiO-QSE facilitate the adsorption of Mn ions, thereby inhibiting their migration. Furthermore, the disproportionation of Mn3+ on LiMn2O4 is suppressed by maintaining a highly concentrated Mn2+ layer around the cathode surface, thereby providing cathode protection in accordance with Le Chatelier's principle. The excellent inhibitory effect of UiO-QSE on the dissolution and migration of Mn ions is reflected in the fact that the prepared LiMn2O4|UiO-QSE|Li battery exhibits high discharge capacity (100.2mAh·g-1 after 100 cycles), which is much higher than LiMn2O4|LE|Li (78.1mAh·g-1), and a high capacity retention of 97.91% after 50 cycles at a high-temperature of 45°C. The Li|Li symmetrical cell exhibits an ultralong cycle life of more than 1300h even at a high current density of 1mA cm-2 due to the uniform Li-ion transport channel and high Young's modulus in the UiO-QSE. This study is the first to employ the MOF-QSE strategy to inhibit the dissolution and migration of manganese during cycling, providing a new perspective on the development and enhancement of lithium-manganese-based batteries.

Magnetic properties of potential li-ion battery materials

Lithium-ion batteries (LiBs) have transformed electrochemical energy storage technologies and made a substantial contribution to grid-scale energy storage and the e-mobility revolution. Notwithstanding their many benefits, safety issues—specifically, thermal runaway incidents—have drawn attention from all around the world. In addition to discussing safety concerns, cooling techniques, and the history of battery materials, this study offers a thorough analysis of the growth, difficulties, and developments in Li-ion battery technology. Quantum Espresso software has been used to compute the magnetic characteristics of several potential Li-ion battery materials, which can enhance Li-ion battery performance.

Fluorination Strategies for Mn₃O₄ Nanoparticles: Enhancing Reversibility and Capacity in Li-Ion Batteries

Transition metal oxides (TMOs) occupy an increasing share in the search for new electrode materials for Li-Ion batteries. Despite promising electrochemical performances (up to 1000 mAh g−1 in the case of conversion), these materials have poor cyclability linked primarily to hysteresis phenomena. To improve their electrochemical performance, one strategy consists of reducing the particle size. A second strategy relies on the incorporation of fluorine directly into electrode materials to limit the solid–electrolyte interface (SEI). Our study focuses on the impact of fluorination on the electrochemical performance of manganese oxide obtained by solid combustion synthesis (SCS). Two fluorinating agents were used: pure gaseous molecular fluorine F2 and radical fluorine F• through xenon difluoride XeF2 decomposition. The use of F2 results in strong fluorination localized primarily at the particle surface while XeF2 diffuses deeper into the particle, resulting in the removal of residual carbon from the synthesis by combustion. The electrochemical performance of the oxide fluorinated with XeF2 reaches more than 750 mAh g−1 after 160 cycles, whereas that of the oxide fluorinated by F2 barely exceeds that of the non-fluorinated oxide, less than 200 mAh g−1 after 200 cycles.

Operando Synchrotron X-Ray Absorption Spectroscopy: A Key Tool for Cathode Material Studies in Next-Generation Batteries.

Rechargeable batteries are central to modern energy storage systems, from portable electronics to electric vehicles. The cathode material, a critical component, largely dictates a battery's energy density, capacity, and overall performance. This review focuses on the application of operando X-ray absorption spectroscopy (XAS) to study cathode materials in Li-ion, Na-ion, Li-S, and Na-S batteries. Operando XAS provides real-time insights into the local electronic structure, oxidation states, and coordination environments, which are crucial for understanding complex electrochemical processes, such as redox reactions, phase transitions, and structural degradation. The review highlights the strengths of hard and soft XAS techniques in probing transition metal (TM) and anionic redox processes, particularly in layered oxide cathodes, where reversible oxygen redox and TM behavior are pivotal. The role of operando XAS is also explored in analyzing conversion-type S-based cathodes, where it helps unravel the intricate reaction mechanisms. Furthermore, the review addresses the challenges of in situ cell design for operando XAS, especially under ultrahigh vacuum conditions for soft XAS. By discussing recent advancements and future directions, this review underscores the critical role of operando XAS in driving innovation and improving the design and performance of next-generation battery technologies.

Lithium Tracer Diffusion in LixCoO2 and LixNi1/3Mn1/3Co1/3O2 (x = 1, 0.9, 0.65)-Sintered Bulk Cathode Materials for Lithium-Ion Batteries

The knowledge of Li diffusivities in electrode materials of Li-ion batteries (LIBs) is essential for a fundamental understanding of charging/discharging times, maximum capacities, stress formation and possible side reactions. The literature indicates that Li diffusion in the cathode material Li(Ni,Mn,Co)O2 strongly increases during electrochemical delithiation. Such an increased Li diffusivity will be advantageous for performance if it is present already in the initial state after synthesis. In order to understand the influence of a varying initial Li content on Li diffusion, we performed Li tracer diffusion experiments on LixCoO2 (LCO) and LixNi1/3Mn1/3Co1/3O2 (NMC, x = 1, 0.9, 0.65) cathode materials. The measurements were performed on polycrystalline sintered bulk materials, free of additives and binders, in order to study the intrinsic properties. The variation of Li content was achieved using reactive solid-state synthesis using pressed Li2CO3, NiO, Co3O4 and/or MnO2 powders and high temperature sintering at 800 °C. XRD analyses showed that the resultant bulk samples exhibit the layered LCO or NMC phases with a low amount of cation intermixing. Moreover, the presence of additional NiO and Co3O4 phases was detected in NMC with a pronounced nominal Li deficiency of x = 0.65. As a tracer source, a 6Li tracer layer with the same chemical composition was deposited using ion beam sputtering. Secondary ion mass spectrometry in depth profile mode was used for isotopic analysis. The diffusivities followed the Arrhenius law with an activation enthalpy of about 0.8 eV and were nearly identical within error for all samples investigated in the temperature range up to 500 °C. For a diffusion mechanism based on structural Li vacancies, the results indicated that varying the Li content does not result in a change in the vacancy concentration. Consequently, the design and use of a cathode initially made of a Li-deficient material will not improve the kinetics of battery performance. The possible reasons for this unexpected result are discussed.

Unveiling the Advantages of Silicon Nitride Nanoparticle Anodes for Enhanced Cyclic Stability, Rate Performance, and Mechanical Robustness.

Silicon nitride, known as a convertible-type silicon-based anode material, has emerged as a promising alternative to pure Si anodes, featuring improved cyclic stability, rate performance, and kinetics. This study reports on the electrochemical properties of silicon nitride nanoparticles as an anode material. It demonstrates that this anode outperforms a pure silicon anode in terms of cyclic stability and kinetics. Silicon nitride undergoes conversion during initial lithiation, forming a matrix phase that facilitates charge carrier transport that enhances performance. As a result, silicon nitride retains 73% of its initial charge capacity, whereas only 55% for pure silicon, after 350 cycles. The in situ-formed ion-conductive matrix promotes Li-ion transport, yielding an improved rate performance. At 1 C rate, silicon nitride achieves 585 mA h g-1 (38% of C/20 capacity) after 85 cycles, surpassing pure silicon's 470 mA h g-1 (22% of C/20 capacity). Electrochemical impedance indicates silicon nitride's faster ionic conductivity and lower resistance compared to pure silicon. Electrochemical dilatometer findings show less electrode thickness increase in silicon nitride (29%) than in pure silicon (60%) during initial lithiation. Silicon nitride demonstrates potential as an attractive anode material for future Li-ion batteries due to improved cyclic stability, superior rate performance, and stable electrode geometry.

Unraveling 3d Transition Metal (Ni, Co, Mn, Fe, Cr, V) Ions Migration in Layered Oxide Cathodes: A Pathway to Superior Li-Ion and Na-Ion Battery Cathodes.

Li-ion and Na-ion batteries are promising systems for powering electric vehicles and grid storage. Layered 3d transition metal oxides AxTMO2 (A = Li, Na; TM = 3d transition metals; 0<x≤2) have drawn extensive attention as cathode materials due to their exceptional energy densities. However, they suffer from several technical challenges caused by crystal structure degradation associated with TM ions migration, such as poor cycling stability, inferior rate capability, significant voltage hysteresis, and serious voltage decay. Aiming to tackle these challenges, this review provides an in-depth discussion and comprehensive understanding of the TM ions migration behaviors in AxTMO2. First, the key thermodynamics and kinetics that impact TM ions migration are discussed, covering ionic radius, electronic configuration, crystal structure arrangement, and migration energy barrier. In particular, details are provided regarding the universal and specific migration characteristics of Ni, Co, Mn, Fe, Cr, and V ions in layered cathode materials. Subsequently, the impacts of these migrations on electrochemical performance are emphasized in terms of the fundamental science behind technical issues, and strategies to modulate TM ions migration for advanced cathode materials development are summarized. Besides, characterization techniques for probing the TM ions migration are present, like neutron diffraction (ND), scanning transmission electron microscopy (STEM), nuclear magnetic resonance (NMR), and others. Finally, future directions in this regard are comprehensively concluded. This review offers valuable insights into the basic design of advanced layered oxide cathode materials for Li-ion and Na-ion batteries.

Porous CuF2 derived from MOFs as cathode materials for Li-ion batteries

Copper fluoride (CuF2) has demonstrated great potential as a cathode material for LIBs owing to its high energy density. In this study, a two-step synthesis method was proposed to prepare porous CuF2 by using Cu-based metal-organic frameworks (MOFs). N2 adsorption-desorption isotherms, along with SEM and TEM analyses, proved that the intermediates CuO exerted a certain influence on the pore structure of the final CuF2 products. The porous CuF2 achieved a first discharge capacity of 554 mAh ⋅ g[Formula: see text] at 0.1C. At a high current density of 5C, it delivered a rate capacity of 413 mAh ⋅ g[Formula: see text] within 1.5–4.2 V. The results of electrochemical impedance spectroscopy show that varying degrees of porosity influence the lithium-ion diffusion coefficient, leading to differences in electrochemical performances.

Achieving precise control over the molecular periphery of dibenzoixenes through modular synthesis.

Nanographenes and polycyclic aromatic hydrocarbons, both finite forms of graphene, are promising organic semiconducting materials because their optoelectronic and magnetic properties can be modulated through precise control of their molecular peripheries. Several atomically precise edge structures have been prepared by bottom-up synthesis; however, no systematic elucidation of these edge topologies at the molecular level has been reported. Herein, we describe rationally designed modular syntheses of isomeric dibenzoixenes with diverse molecular peripheries, including cove, zigzag, bay, fjord, and gulf structured. The single-crystal structures of dibenzo[a,p]ixene and dibenzo[j,y]ixene reveal enantiomeric pairs with helically twisted cove edges and packing structures. The molecular edge structures are identified from the C-H bonds of the dibenzoixenes using Fourier-transform infrared spectroscopy with different vibrational modes, which were further explained using density functional theory calculations. Electron spin resonance spectroscopy indicate that the zigzag-edged molecular periphery significantly affects the magnetic properties of the material. Furthermore, the electrochemical characteristics, examined using dibenzoixenes as anode materials in Li-ion batteries, reveal that the dibenzo[a,p]ixene exhibits promising Li intercalation behaviors with a specific capacity of ~120 mAh g-1. The findings of this study could facilitate the synthesis of larger [[EQUATION]]-extended systems with engineered molecular peripheries and potential application in organic electronics.

Highly Crystalline Contorted Coronene Homologous Molecule as Superior Organic Anode Material for Full-Cell Li-Ion Batteries.

Organic anode materials have garnered attention for use in rechargeable Li-ion batteries (LIBs) owing to their lightweight, cost-effectiveness, and tunable properties. However, challenges such as high electrolyte solubility and limited conductivity, restrict their use in full-cell LIBs. Here, we report the use of highly crystalline Cl-substituted contorted hexabenzocoronene (Cl-cHBC) as an efficient organic anode for full-cell LIBs. By employing an antisolvent crystallization method, the crystallinity of the Cl-cHBC materials has been significantly enhanced, achieving superior electrochemical performance in a half-cell configuration. Furthermore, when incorporated with the conventional lithium iron phosphate (LFP) cathode, the Cl-cHBC||LFP full-cell delivers a high discharge cell voltage of 3.0 V, surpassing the voltages of conventional lithium-titanium oxide anodes and offering improved power densities. In addition, a full cell with high-voltage lithium cobalt oxide and single-crystal high-nickel-based cathodes demonstrates enhanced electrochemical characteristics, including elevated discharge voltages, stable C-rate performance, and cycle endurance. Thus, the proposed highly crystalline Cl-cHBC anode is a promising next-generation solution for LIB applications.

Probabilistic Modelling of the Nonlinear Mapping between Voltammograms and the Grain Size of the Electrode Material in Li-Ion Batteries Using Optimally Tuned Gaussian Process Regression Models

Abstract The electrochemical response, and hence the performance, of lithium-ion batteries (LIBs) is heavily influenced by the microstructure of their electrode material, particularly grain size. Thus, a model that correlates electrode microstructure with electrochemical response can aid in optimizing these characteristics for better battery performance. However, no existing studies address this modeling problem.&amp;#xD; &amp;#xD;This study fills this gap by using data-driven probabilistic modelling to map the electrochemical response (voltammograms) to electrode grain size. The methodology is demonstrated on six datasets containing voltammograms from in-silico cyclic voltammetry experiments on LiMn2O4 electrode particles. Feature vectors created using seven features of the voltammogram were combined with the corresponding known grain size values to construct data-driven probabilistic models via Gaussian process regression (GPR) with five different kernels for each dataset. The hyperparameters of the kernels used in these GPR models were optimised using grid-search. Performance evaluation through bias-variance analysis demonstrated strong predictive accuracy of the developed models. Additionally, the comparisons across datasets and kernels showed the Gaussian and Rational Quadratic kernels' effectiveness in modelling various relationships. The obtained results substantiate the efficacy of the proposed approach, revealing significant insights and encouraging further exploration.

Elucidation of the Co4+ state with strong charge-transfer effects in charged LiCoO2 by resonant soft X-ray emission spectroscopy at the Co L3 edge.

To understand the electronic-structure change of LiCoO2, a widely used cathode material in Li-ion batteries, during charge-discharge, we performed ex situ soft X-ray absorption spectroscopy (XAS) and resonant soft X-ray emission spectroscopy (RXES) of the Co L3 edge in combination with charge-transfer multiplet calculations. The RXES profile significantly changed for the charged state at 4.2 V vs. Li/Li+, corresponding to the oxidation reaction from a Co3+ low-spin state for the initial state, while the XAS profile exhibited small changes. For the 4.2-V charged state, we confirmed that approximately half of the initial Co3+ ions were oxidized to Co4+ ions. The multiplet calculation of the RXES results revealed that the Co4+ state has a negative charge-transfer energy and the d6L̲ state (L̲ is a ligand hole) is the most stable. Therefore, the O 2p hole created by the strong charge-transfer effect plays a major role in the redox reaction of LiCoO2.

Cathode properties of a controlled crystallinity nano-Li1.2Cr0.4Mn0.4O2 cathode for lithium ion batteries

The milled-Li1.2Cr0.4Mn0.4O2 (milled-LCMO) cathode, a promising material for next-generation Li ion batteries, is prepared by dry ball-milling of layered rocksalt-type Li1.2Cr0.4Mn0.4O2 (layered-LCMO) obtained by solid-state synthesis.