Synthesis and Characterization of Polymer Electrolyte Using Deep Eutectic Solvents and Electrospun Poly(vinyl alcohol) Membrane

Abstract

Organic polymer electrolytes attracted a great deal of attention and research in the field of energy conversion and energy storage due to their benefits such as appreciable ionic conductivity and transference number, improved mechanical strength, thermal stability, and better interaction with the electrodes. In this study, a polymer electrolyte was synthesized from poly­(vinyl alcohol) (PVA) by electrospinning technique followed by soaking in a series of deep eutectic solvents (DESs) to enhance the electrical conductivity of the product. The result was a very thin, nonwoven membrane. The produced membranes showed appreciable improvement in electrical conductivity from 2.78 × 10–6 to 2.27 × 10–2 S/cm after soaking in DES2. The observed improvement in electrical properties opens the possibility for the PVA membranes to find their applications in batteries, storage cells, flexible thermoelectric devices, sensors, and solar cells.

Evolution of microscopic heterogeneity and dynamics in choline chloride-based deep eutectic solvents

“…Deep eutectic solvents (DESs) are an emerging class of materials with exceptional properties that make them promising for applications in solar cells 1 , redox flow batteries 2 – 4 , thermoelectric energy conversion 5 , supercapacitors 6 , chemical sensors 7 , chemical separation processes 8 , drug solubility 9 , and environmentally benign solvents for chemical synthesis and biomass processing 10 , 11 . DESs are mixtures of two or more species, typically a hydrogen bond donor (HBD) species and a hydrogen bond acceptor (HBA) species, that results in a depressed melting temperature significantly below those of the parent compounds 12 – 15 .…”

Ionic Conductivity Enhancement in UHMW PEO Gel Electrolytes Based on Room-Temperature Ionic Liquids and Deep Eutectic Solvents

“…The first research articles on polymer gel electrolytes of DES date from the early 2010s and refer to the preparation by solvent casting of a Li gel electrolyte based on corn starch, using the well-known urea-choline chloride DES and LiTFSI as the Li salt . In the literature, other methodologies to obtain solid or gel electrolytes from DES relying on the use of polymers can be found, such as poly­(vinyl alcohol) electrospun membranes soaked with N , N -diethylethanolammonium chloride and ethylene glycol (EG) DES, in situ monomer polymerization, , or in situ polymer cross-linking . Moreover, it is possible to obtain gels without the addition of polymers, for instance, by gelation of N -methyl acetamide-LiTFSI with tetraethylorthosilicate and formic acid, or self-assembled gels formed by ionic interactions of 1,3:2,4-dibenzylidene- d -sorbitol in different DESs based on choline chloride .…”

Polymeric Backbone Eutectogels as a New Generation of Hybrid Solid-State Electrolytes

“…The concept of solid composite electrolytes (SCE) has received considerable attention in the battery community. − The solid composite electrolyte consists of a liquid lithium-ion conducting electrolyte enclosed within a solid backbone, allowing for a high ionic conductivity combined with the rigidity of a solid and with low vapor pressure. Good examples are the ionogels in which ionic liquids are confined within an inorganic (e.g., silica) or a polymeric (e.g., poly­(ethylene glycol) diacrylate (PEODA)) solid backbone. − ,− ,, …”