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As long as the energy consumption is intended to be more economical and more environmental friendly, electrochemical energy production is under serious consideration as an alternative energy/power source. Among different energy/power storage devices, lithium-ion batteries (LIBs) are currently the best commercially available devices. However, the enhancement of properties such as ionic conductivity and cyclic performances is needed for high-level applications. In search for better electrolyte materials for LIBs, scientists have been investigating on composite polymer electrolytes such as PAN-, PMMA-, PVdF-, PVdF-co-HFP- and PEO-based electrolytes. By electrospinning method of preparation of composite polymer electrolytes, significant improvement in properties can be seen. The sole reason for this is the better surface morphology and interfacial stability exhibited by electrolytes prepared by using this method. The composite polymer electrolytes are electrospun with ceramic fillers such as Al2O3, BaTiO3, MgO and TiO2 to improve the performances of lithium cell for better transportation of ions.

Designing a safer and secure battery technology is always a serious concern for the development of more reliable system. Lithium-ion batteries are considered to be the best battery technology that can deliver better electrochemical performance. Low boiling liquid electrolytes with low volatility threaten the use of lithium-ion batteries due to its explosive nature. For developing safer electrolyte systems swapping of liquid electrolytes are made with polymer based systems. Polyacrylonitrile-based polymer electrolytes are seeking much attention due its high ionic conductivity, thermal stability and its oxidative stability. For developing flexible as well as porous PAN based electrolyte membrane, electrospinning is considered as the effective. It is versatile methods that can results highly porous nanostructures with superior electrochemical properties. This chapter will light up to the development and significance of electrospunned PAN based polymer electrolytes for lithium-ion batteries.

Electrolytes play a crucial role in the development of an efficient batteries. There are different techniques for the fabrication of such polymer electrolytes that are essential since polymer membrane depends on it. A versatile and simple technique or the preparation of such matrix is electrospinning. Polymeric fibres of non-woven membrane offer high ionic conductivity as well as good cycling performance. Electrospun PVdF attained greater attention due to its higher dielectric constant, chemical stability as well as thermal stabilities. Morphology, cycling performance, electrochemical stabilities, etc., were investigated for the improved performance of lithium ion battery. Electrospun polymer blends as well composite polymer electrolytes are promising candidates that are suitable for lithium ion batteries.

Electrolytes are regarded as the key ingredient of batteries. The need for safe and reliable energy storage devices has led to the development of polymer electrolytes. The crystallinity of polymers used as electrolytes influences the ionic conductivity of the electrolytes. The enhancement of ionic conductivity can be achieved by decreasing the crystallinity of the polymers which can be achieved by the incorporation of organic and inorganic fillers. Electrospinning is one of the best methods for the synthesis of polymer membranes for lithium-ion batteries. The present chapter investigates the thermal, physical, mechanical, and electrochemical changes in the polymer electrolytes on the incorporation of the inorganic filler (SiO2). The polymer membranes synthesized by electrospinning is found to be superior in performance owing to the interlinked network structure. A detailed review of the electrospun polymer membrane with silica nanofillers by varying compositions, mode of addition, and complexes have been investigated.

Poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-co-HFP)-based fibers generated through the well-known technique of electrospinning have remained an attractive class of materials utilized as separators as well as solid electrolytes in lithium-ion battery (LIB) systems. In comparison to commercial separators based off polypropylene (PP) and polyethylene (PE), PVdF-co-HFP serves as an advantageous co-polymer, owing to enhanced properties such as high porosities, ionic conductivities as high as of 1 × 10−1 S·cm−1, and capacities higher than 100 mAh g−1 when incorporated into LIBs. The nature of PVdF-co-HFP also allows for facile processing via electrospinning, which in turn leads to fine tunability of properties such as porosity and wettability, which are crucial for superior separator performance. In addition, other properties pertaining to separator stability (i.e., mechanical, thermal, and electrochemical stabilities) can be further improved through the incorporation of ceramic fillers and surface modifications such as plasma treatment and other coating methods. The following chapter is meant to serve as a comprehensive review for the recent progress and state of the art of PVdF-co-HFP’s use in LIBs.

Overexploitation of fossil fuel leads to the serious energy crisis. Alternate source in the post-fossil fuel era is the usage of electrical energy; thus, there is a huge technological research and development in this field. In the field of energy storage systems, lithium-ion batteries have received much attention for a wide variety of applications ranging from electronic devices such as laptops, digital cameras and cell phones. Working procedure of a lithium-ion battery involves as follows: During charging, an external electrical power source forces the current pass in the reverse direction and makes lithium ions migrate from the cathode to the anode across the electrolyte. Among the electrolyte, polymer electrolytes (PE) are the most promising one. These electrolytes are composed of polymers single or as blends with suitable salts giving safety and characteristics to lithium-ion batteries (LIBs). Electrospinning technique is one of the widely used techniques in preparing the electrolyte for LIBs. Electrospun membrane with good mechanical strength and porosity exhibits high uptake when activated with the liquid electrolyte of lithium salt in a mixture of organic solvents and thus help in charge transport. However, crystallinity of single polymer system makes it difficult for charge transport. To reduce the crystallinity and hence to improve the ionic conductivity, polymeric blend-based electrolytes are done by electrospinning technique. This chapter highlights recent advancements and newer trends in electrospun blend PEs by providing an overview of various blend electrolytes prepared by electrospinning technique for application in LIBs.

The effect of blending polyethylene oxide with poly (vinylidene fluoride)–lithium aluminum germanium phosphate (LAGP) composite and in-situ porosity generation on the electrochemical performance of polymer electrolytes based on non-woven fibrous mats is studied. Electrospinning process parameters are controlled to get a fibrous membrane consisting of bead-free, multilayered, three dimensional network structure of ultrafine fibers. The electrospun membranes are subjected to a preferential polymer dissolution process to prepare a highly porous structure. The membranes show high surface roughness with uniformly sized and distributed pores on the fibers. The membranes with good mechanical strength, thermal stability and high porosity exhibit high swelling when activated with liquid electrolyte. The prepared composite polymer electrolytes show high ionic conductivity. The addition of the glass ceramic improves the mechanical and thermal stability, while blending and in-situ porosity generation improves the ionic conductivity, charge–discharge performance, cycling stability, interface properties and compatibility with lithium electrode.

The advantageous properties of both solid soft matter electrolytes and polymer gel electrolytes (PGEs) are combined to develop a electrospun polymer composite electrolyte (PCE) for lithium ion batteries , based on addition of butanedinitrile (BDN, the plastic crystal) to poly(vinylidenefluoride- co -hexafluoropropylene) {P(VdF- co -HFP)} (semi crystalline polymer). Polymer composite electrolytes are prepared by activating the fibrous membrane with 1 M LiPF 6 in EC/DEC. The electrochemical characterization shows that the addition of BDN significantly improves the ionic conductivity of composite electrolytes even at lower temperatures due to the active role played by BDN in ion conduction. Also the compatibility of the polymer composite electrolyte with lithium electrode improves by incorporation of BDN. Galvanostatic cycling test demonstrates the suitability of these polymer composite electrolytes for lithium ion batteries in both Li/PCE/LiFePO 4 (half cell) and LTO/PCE/LiFePO 4 (full cell) configurations. The addition of BDN improves the charge discharge performance and cycling stability of the polymer composite electrolytes.

Effect of poly(ethylene oxide) on the electrochemical properties of polymer electrolyte based on electrospun, non-woven membrane of PVdF is demonstrated. Electrospinning process parameters are controlled to get a fibrous membrane consisting of bead-free, uniformly dispersed thin fibers with diameter in the range of 1.5–1.9 μm. The membrane with good mechanical strength and porosity exhibits high uptake when activated with the liquid electrolyte of lithium salt in a mixture of organic solvents. The polymer gel electrolyte shows ionic conductivity of 4.9 × 10−3 S cm−1 at room temperature. Electrochemical performance of the polymer gel electrolyte is evaluated in Li/polymer electrolyte/LiFePO4 coin cell. Good performance with low capacity fading on charge–discharge cycling is demonstrated.

Hybrid organic–inorganic polymer gel electrolytes (PGEs) based on polymer–clay nanocomposite microporous membrane containing 1 M lithium hexafluorophosphate (LiPF6) in ethylene carbonate/diethyl carbonate (EC/DEC) are fabricated and their electrochemical characteristics in lithium ion batteries are studied. Poly(vinylidene fluoride) (PVdF)–clay nanocomposite membrane containing different clay loading are prepared by phase inversion method. Aqueous suspension of montmorrillonite (MMT) clay in dimethyl acetamide (DMAc) is used as the nano-clay. The morphology of the clay dispersion with sonication time is studied by environmental scanning electron microscope (E-SEM). The intercalation/exfoliation of polymer–clay nanocomposite is characterized by X-ray diffraction (XRD). Differential scanning calorimetry (DSC) and thermal gravimetric analysis are used for the evaluation of thermal properties. DSC analysis shows that crystallinity of nanocomposite decreases with increasing nano-clay content. The effect of clay on the membrane morphology, ionic conductivity and electrochemical properties of the PGEs in lithium ion rechargeable batteries are studied and results are compared. Incorporation of 2 wt.% nano-clay in PGE enhances its ionic conductivity from 0.78 to 3.08 mS cm−1 at room temperature. Li-ion half cell comprising of Li/PVdF–clay(2 wt.%)-PGE/LiMn2O4 delivers high charge–discharge capacity (∼120 mAh g−1) and shows stable cycle performance.

A new approach for fabricating polymer gel electrolytes (PGEs) based on electrospun poly(vinylidenefluoride-co-hexafluoropropylene) {P(VdF-co-HFP)} incorporated with layered nanoclay has been employed to enhance the ionic conductivity and electrochemical properties of P(VdF-co-HFP) without compromising its mechanical strength. The effect of layered nanoclay on properties of membranes has been evaluated by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Surface morphology of the membranes has been studied using field-emission scanning electron microscopy (FE-SEM). Polymer gel electrolytes are prepared by soaking the fibrous membrane into 1 M LiPF6 in EC/DEC. The electrochemical studies show that incorporation of layered nanoclay into the polymer matrix greatly enhanced the ionic conductivity and compatibility with lithium electrodes. The charge–discharge properties and cycling performance of Li/LiFePO4 cells comprising nanocomposite polymer gel electrolytes have been evaluated at room temperature.