Electrospun polymer nanofibers: the booming cutting edge technology

Electrospinning has been recognized as a simple and efficient technique for the fabrication of ultrathin fibers from a variety of materials including polymers, composite and ceramics. Significant progress has been made throughout the past years in electrospinning and the resulting fibrous structures have been exploited in a wide range of potential applications. This article reviews the state-of-art of electrospinning to prepare fibrous electrode materials and polymer electrolytes based on electrospun membranes in the view of their physical and electrochemical properties for the application in lithium batteries. The review covers the electrospinning process, the governing parameters and their influence on fiber or membrane morphology. After a brief discussion of some potential applications associated with the remarkable features of electrospun membranes, we highlight the exploitation of this cutting edge technology in lithium batteries. Finally the article is concluded with some personal perspectives on the future directions in the fascinating field of energy storag

Graphene: Chemistry and Applications for Lithium-Ion Batteries

In the present era, different allotropes of carbon have been discovered, and graphene is the one among them that has contributed to many breakthroughs in research. It has been considered a promising candidate in the research and academic fields, as well as in industries, over the last decade. It has many properties to be explored, such as an enhanced specific surface area and beneficial thermal and electrical conductivities. Graphene is arranged as a 2D structure by organizing sp2 hybridized C with alternative single and double bonds, providing an extended conjugation combining hexagonal ring structures to form a honeycomb structure. The precious structure and outstanding characteristics are the major reason that modern industry relies heavily on graphene, and it is predominantly applied in electronic devices. Nowadays, lithium-ion batteries (LIBs) foremostly utilize graphene as an anode or a cathode, and are combined with polymers to use them as polymer electrolytes. After three decades of commercialization of the lithium-ion battery, it still leads in consumer electronic society due to its higher energy density, wider operating voltages, low self-discharge, noble high-temperature performance, and fewer maintenance requirements. In this review, we aim to give a brief review of the domination of graphene and its applications in LIBs

Novel polymer electrolyte based on cob-web electrospun multi component polymer blend of polyacrylonitrile/poly(methyl methacrylate)/polystyrene for lithium ion batteries : preparation and electrochemical characterization

The aim of the present work is to prepare a novel polymer electrolyte (PE) based on multi component polymer blend of polyacrylonitrile (PAN), poly(methyl methacrylate) (PMMA) and polystyrene (PS) with varying compositions by electrospinning. Structural characterization is carried out using X-ray diffraction (XRD). The thermal and crystalline properties of the blend are studied by thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. Morphology of the membrane is examined by field emission scanning electron microscope (FE-SEM). The voids and cavities generated by the interlaying of the fibers are effectively utilized for the preparation of PE by loading with lithium hexafluorophosphate (LiPF6) dissolved in ethylene carbonate (EC)/diethyl carbonate (DEC). The ionic conductivity of the polymer blend electrolyte is studied by varying the PMMA and PS content in the PAN matrix. The blend polymer electrolyte shows ionic conductivity of about 3.9 × 10(−3) S cm(−1). The performance evaluation in coin cells show good charge–discharge properties and stable cycle performance under the test conditions. The result shows that the prepared polymer blend electrolytes are promising materials for lithium ion batteries.Accepted versio

Facile synthesis and electrochemical properties of alpha-phase ferric oxide hematite cocoons and rods as high-performance anodes for lithium-ion batteries

Unique cocoon- and rod-shaped alpha-phase ferric oxide, hematite (α-Fe2O3) is prepared by a simple, scalable and surfactant-free chimie douce synthesis. The structure and morphology is confirmed by x-ray diffraction, field-emission scanning electron microscopy and high-resolution transmission electron microscopy. The electrochemical properties of α-Fe2O3 anodes are investigated using cyclic voltammetry, galvanostatic charge-discharge cycling and electrochemical impedance spectroscopy. The mesoporous α-Fe2O3 exhibited an initial discharge capacity >1741 mAh/g with excellent cycling performance and rate capabilities. The solvent used for the preparation of α-Fe2O3 plays a key role in determining the morphology of the materials, which greatly influenced its electrochemical properties.Published versio

High-Performing Mesoporous Iron Oxalate Anodes for Lithium-Ion Batteries

Mesoporous iron oxalate (FeC₂O₄) with two distinct morphologies, i.e., cocoon and rod, has been synthesized via a simple, scalable chimie douce precipitation method. The solvent plays a key role in determining the morphology and microstructure of iron oxalate, which are studied by field-emission scanning electron microscopy and high-resolution transmission electron microscopy. Crystallographic characterization of the materials has been carried out by X-ray diffraction and confirmed phase-pure FeC₂O₄·2H₂O formation. The critical dehydration process of FeC₂O₄·2H₂O resulted in anhydrous FeC₂O₄, and its thermal properties are studied by thermogravimetric analysis. The electrochemical properties of anhydrous FeC₂O₄ in Li/FeC₂O₄ cells are evaluated by cyclic voltammetry, galvanostatic charge–discharge cycling, and electrochemical impedance spectroscopy. The studies showed that the initial discharge capacities of anhydrous FeC₂O₄ cocoons and rods are 1288 and 1326 mA h g^–1, respectively, at 1<i>C</i> rate. Anhydrous FeC₂O₄ cocoons exhibited stable capacity even at high <i>C</i> rates (11<i>C</i>). The electrochemical performance of anhydrous FeC₂O₄ is found to be greatly influenced by the number of accessible reaction sites, morphology, and size effects

Tailor-Made Electrospun Multilayer Composite Polymer Electrolytes for High-Performance Lithium Polymer Batteries

A novel tailor-made multilayer composite polymer electrolyte, consisting of two outer layers of electrospun polyacrylonitrile (PAN) and one inner layer of poly(vinyl acetate) (PVAc)/poly(methyl methacrylate) (PMMA)/poly(ethylene oxide) (PEO) fibrous membrane, was prepared using continuous electrospinning. These membranes, which are made up of fibers with diameters in the nanometer range, were stacked in layers to produce interconnected pores that result in a high porosity. Gel polymer electrolytes (GPEs) were prepared by entrapping a liquid electrolyte (1 M LiPF6 in ethylene carbonate/dimethyl carbonate) in the membranes. The composite membranes exhibited a high electrolyte uptake of 450-510%, coupled with an improved room temperature ionic conductivity of up to 4.72 mS cm(-1) and a high electrochemical stability of 4.6 V versus Li/Li+. Electrochemical investigations of a composite membrane of PAN-PVAc-PAN, with a LiFePO4 cathode synthesized in-house, showed a high initial discharge capacity of 145 mAh g(-1), which corresponds to 85% utilization of the active material, and displayed stable cycle performance