Electrodes For Rechargeable Lithium Batteries Research Articles

High capacity SnxSbyCuz composite anodes for lithium ion batteries

To increase the volumetric discharge capacity of negative electrode for rechargeable lithium batteries, a composite anode SnxSbyCuz has been synthesized by using high energy mechanical ball milling method. The synthesized composite anode materials have been characterized by X-ray diffraction and SEM analysis. The charge/discharge characteristics of the fabricated coin cells have been evaluated galvanostatically in the potential range 0.01–2 V using 1 M LiPF6 in 1:1 EC/DEC as electrolyte. Results indicate that the composition with 90 wt% Sn, 8 wt% Sb and 2 wt% Cu delivers an average discharge capacity of 740 mAh g−1 over the investigated 50 cycles which is a potential candidate for use as an anode material for lithium rechargeable cells.

Fused Heteroaromatic Organic Compounds for High‐Power Electrodes of Rechargeable Lithium Batteries

AbstractOrganic redox compounds are emerging electrode materials for rechargeable lithium batteries. However, their electrically insulating nature plagues efficient charge transport within the electroactive bulk. Alternative to the popular solution of elaborating nanocomposite materials, herein we report on a molecular‐level engineering strategy towards high‐power organic electrode materials with multi‐electron reactions. Systematic comparisons of anthraquinone analogues incorporating fused heteroaromatic structures as cathode materials in rechargeable lithium batteries reveal that the judicious incorporation of heteroaromatics improves the cell performance in terms of specific gravimetric capacity, working potential, rate capability, and cyclability. Combination studies with morphological observation, electrochemical impedance characterization, and theoretical modeling provide insight into the advantage of heteroaromatic building blocks. In particular, benzofuro[5,6‐b]furan‐4,8‐dione (BFFD) bearing furan moeities shows a reversible capacity of 181 mAh g−1 when charged/discharged at 100C, corresponding to a power density of 29.8 kW kg−1. These results have pointed to a general design route of high‐rate organic electrode materials by rational functionalization of redox compounds with appropriate heteroaromatic units as versatile structural tools.

Factors that Affect the Phase Behavior of Multi-Component Olivine (LiFexMnyCo1-x-yPO4; 0 < x, y< 1) in Lithium Rechargeable Batteries: One-Phase Reaction vs. Two-Phase Reaction

The structural evolution of multi-component olivines upon delithiation and lithiation was investigated by ex-situ X-ray diffraction. We found that one-phase de/lithiation occurs for multi-component olivines for a fairly large compositional range of transition metal species given that two-phase de/lithiation is generally accepted for olivine cathodes. We discuss the driving force that determines the phase behavior (two-phase reaction vs. one-phase reaction) of olivines in terms of enthalpy of mixing presumably dominated from the electrostatic interaction among cations and the elastic strain stored in the crystal due to the volume change of redox active element. We believe that this fundamental study on the phase behavior of olivines will provide insight into the intrinsic electrochemical properties of olivine electrodes for rechargeable lithium batteries.

Defect and dopant properties of the α- and β-polymorphs of the Li3FeF6 lithium battery material

Li3FeF6 has attracted recent interest as a promising positive electrode for rechargeable lithium batteries. The defect chemistry and cation doping behaviour of the α- and β-polymorphs of Li3FeF6 have been investigated by advanced atomistic modelling techniques. Our simulations show good reproduction of both monoclinic (α) and orthorhombic (β) experimental structures, which are related to the cryolite crystal structure. The most favourable defect types are found to be the Li Frenkel and off-stoichiometry (Li-excess) disorder, suggesting that interstitial lithium is possible in the cryolite structure, and is important in rationalizing the lithium intercalation chemistry. Monovalent dopant substitution for Li and divalent substitution for Fe are energetically favourable, and could be a synthesis strategy to optimise the electrochemical behaviour of Li3FeF6.

In-situ synthesis of magnetite/expanded graphite composite material as high rate negative electrode for rechargeable lithium batteries

Magnetite (Fe3O4)/expanded graphite (EG) composite material is prepared through the oxidation progress of ferrocene–graphite intercalation compound in acetone solution. The reactions occur in this system and lead to in-situ synthesis of the composite with nanosized magnetite and expanded graphite. Due to the lithium insertion/extraction experiment, the Fe3O4/EG composite material shows high reversible capacities (ca. 720 mA h g−1 at 120 mA g−1 charge current) and excellent rate performances (ca. 630 mA h g−1 at 600 mA g−1, 420 mA h g−1 at 6000 mA g−1 and 360 mA h g−1 at 9000 mA g−1charge current). Owning to the strong interaction between Fe3O4 and EG from in-situ synthesis, it is demonstrated that these properties of this novel Fe3O4/EG composite material will be an idea candidate for the negative electrode material of high-current lithium ion battery.

Facile Synthesis of FeF3 and Its Application to Positive Electrode for Rechargeable Lithium Batteries

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ChemInform Abstract: Double Carbon Coating of LiFePO4 as High Rate Electrode for Rechargeable Lithium Batteries.

AbstractMicrometer‐size LiFePO4 spheres with homogeneous double carbon coating layers are prepared as potential electrode materials for rechargeable lithium batteries.

Electrochemical behavior and passivation of current collectors in lithium-ion batteries

This paper examines several metals that are commonly employed as current collectors of positive and negative electrodes for rechargeable lithium batteries. Current collectors must be electrochemically stable when in contact with the cell component during the potential operation window of an electrode. Various electrochemical techniques have been used to investigate the corrosion of current collector materials. In practice, continued corrosion of current collectors leads to a gradual increase in the internal resistance of cells, which causes the capacity to fade gradually. Corrosion of the current collector may induce a short-circuit, affecting its safety. Thus, the formation of thick and compact, protective passive film on the metal surface is highly important so as to ensure battery performance and safety. Depending on the salts and additives, different types of protective films are formed. The solubility of these surface layers in the electrolyte is a determining factor in the overall stability of the current collector. In this review, we introduce the electrochemical behavior and protective film formation processes of various metallic current collectors in representative electrolytes.

Double Carbon Coating of LiFePO4 as High Rate Electrode for Rechargeable Lithium Batteries

, and prom-ising electrochemical performance. This single-carbon-coating material was composed of micrometer-scale secondary parti-cles containing nanoscale carbon-coated primary particles; this morphology provided interconnected open pores that favor elec-trolyte absorption and signifi cantly reduce the diffusion path of the lithium ions. This feature, combined with the high tap density, resulted in electrodes having high volumetric energy density and rate capability. Here we report a double coating process that greatly improves the uniformity of the carbon coating on both the primary and secondary LiFePO

Nanostructured Aluminum and Lithium Electrodes for Rechargeable Lithium Batteries

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ChemInform Abstract: Electrophoretic Fabrication of Positive Electrodes for Rechargeable Lithium Batteries.

ChemInform Abstract: Electrophoretic Fabrication of Positive Electrodes for Rechargeable Lithium Batteries.

Double Carbon Coating of LiFePO4 as High Rate Electrode for Rechargeable Lithium Batteries

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ChemInform Abstract: Sn‐0.4BPO4 Composite as a Promising Negative Electrode for Rechargeable Lithium Batteries.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Stibnite (Sb2S3) and its amorphous composite as dual electrodes for rechargeable lithium batteries

Orthorhombic Sb2S3 (stibnite) and its amorphous Sb2S3/C composite were synthesized by solid-state routes, such as heat treatment and high energy mechanical milling (HEMM). X-ray diffraction, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy confirmed that the amorphous Sb2S3/C composite was composed of amorphous Sb2S3 phases distributed uniformly within an amorphous carbon matrix. The electrochemical reaction mechanism of amorphous Sb2S3/C with Li was examined by extended X-ray absorption fine structure analyses. The fabricated amorphous Sb2S3/C composite electrode showed excellent electrochemical properties, such as a high energy density (1st charge: 757 mAh g−1), long cyclability (ca. 600 mAh g−1 over 100 cycles), and good initial Coulombic efficiency (ca. 85%). When tested within various voltage windows, the amorphous Sb2S3/C composite electrode was found to be suitable for use as a dual electrodes, such as the anode in Li-ion batteries or the cathode in Li/S batteries.

Sn-0.4BPO 4 composite as a promising negative electrode for rechargeable lithium batteries

The structural and textural properties of a Sn-0.4BPO 4 composite material synthesized by ex situ dispersion of β-Sn in a BPO 4 matrix were investigated by using several complementary techniques to study the global order (XRD, TGA-DSC, SEM-XEDS) and the local order (FT-IR, 119Sn Mössbauer spectroscopy and X-ray absorption spectroscopy). The results reveal that the composite material consists of three main components: an electrochemically active species “Sn”, an inactive matrix “BPO 4”, and an amorphous Sn(II) borophosphate which acts as a link between the two former and which improves the cohesion of the composite. The electrochemical performances of the composite material were tested in Swagelok-type cells with metallic Li as counter-electrode. It shows a high reversible capacity of about 500 mAh g −1 at a C/20 rate, and a very good stability under cycling even at very fast rates of C or C/1.3.

Electronic and Electrochemical Properties of Nanosized and Micrometric α-MoO3 Particles as Positive Electrode for Rechargeable Lithium Batteries

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Graphene-based electrode materials for rechargeable lithium batteries

Recent progress in the study of graphene has triggered a gold rush for exploiting its possible applications in various areas. Graphene-containing carbonaceous materials have long been selected as electrodes in rechargeable lithium batteries. However, the understanding of the relationship between material structure and electrode performance is still poor due to the complexity of the carbon structures, which hinders the development of high performance batteries. Now it is time to focus on the structure–property relationship of carbonaceous electrodes again, but from the viewpoint of graphene.

Synthesis of Ordered Mesoporous Li–Mn–O Spinel as a Positive Electrode for Rechargeable Lithium Batteries

Synthesis of Ordered Mesoporous Li–Mn–O Spinel as a Positive Electrode for Rechargeable Lithium Batteries

Synthesis of Ordered Mesoporous Li–Mn–O Spinel as a Positive Electrode for Rechargeable Lithium Batteries

Sturdy spinel: A mesoporous Li–Mn–O spinel (Li1.12Mn1.88O4) with superior rate capability at ambient temperature is synthesized. Comparable stability to the bulk material at elevated temperatures is also observed, despite a surface area of 90 m2 g−1 for the mesopore, suggesting that the internal mesopore surfaces are more stable than the external surface.

Overpotential and electrochemical impedance analysis on Cr 2O 3 thin film and powder electrode in rechargeable lithium batteries

The overpotentials of Cr 2O 3 thin film and powder electrodes as well as various benchmark anodes and cathodes in rechargeable lithium batteries have been compared by analyzing the galvanostatic voltage profiles. Li-storage in the Cr 2O 3 electrode through the conversion reaction shows higher overpotential values than through other Li-storage mechanisms. The origins of the high overpotential of the Cr 2O 3 electrode have been studied by electrochemical impedance spectroscopy. It is found that the ohmic polarization, charge transfer resistance and diffusion impedance of the Cr 2O 3 electrode decrease significantly with the insertion of lithium and increase with the extraction of lithium. The calculated overpotential contribution from the diffusion impedance is well consistent with the value deduced from the galvanostatic voltage profiles. It means that the sluggish diffusion should be the main origin for high polarization of Cr 2O 3 electrodes.