Ionic liquids: environmentally sustainable materials for energy conversion and storage applications

Abstract

Ionic liquids (ILs), known as green designer solvents, have shown tremendous application potential in various elds of science and technology. Their unusual and unique physicochemical properties have attracted researchers worldwide from interdisciplinary research areas. ILs possess high boiling point and low volatility, that makes them suitable environmentally benign candidates for many potential applications. The more important aspect associated with ILs is their physicochemical properties can be effectively changed for desired applications just by tuning the structure of the cationic and/or anionic part of ILs. Furthermore, these environmentally benign designer materials can be used as both electrolytes as well as solvents depending on the requirement. Owing to thedistinctive properties such as low volatility, high thermal and electrochemical stability, better ionic conductivity, ILs are nowadays immensely used in variety of energy applications, particularly in the development of green and sustainable energy storage and conversion devices. Suitable ILs are designed for speci c purposesto be used as electrolytes and/or solvents for fuel cells, lithium-ion batteries, supercapacitors(SCs) and solar cells. Herein, we have highlighted the utilization of ILs as unique green designer materials in Li-batteries, fuel cells,SCs and solar cells. This review will enlighten the promising prospects of these unique environmentally sustainable materials for next-generation green energy conversion and storage devices.

Thermal and Physical Properties of CO2-Reactive Binary Mixtures

“…The 21st century marks the upsurge in development of nontraditional solvents, alternatives to volatile organics in chemical processes. − The alternate media encompasses a wide ranging solvents including ionic liquids (ILs), low transition temperature mixtures (LTTM), and deep eutectic solvents (DESs). − LTTMs are a subclass of the immensely popular deep eutectic solvents (DESs); the latter has a defined eutectic point, while the former solvents only show a glass transition temperature ( T g ). − DESs and LTTMs are composed of two main constituents, a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA) associated via a H-bonding network to form a liquid phase. The formation and the physicochemical properties including thermal stability, density, viscosity, molar volume, surface tension, and polarity of these mixtures are largely governed by the chemical identity of the HBA and HBD. − The easy tunability afforded via the compositional changes and vast library of constituents provides easy access to design solvents with desirable properties.…”

A Comprehensive Review of Novel Emerging Electrolytes for Supercapacitors: Aqueous and Organic Electrolytes Versus Ionic Liquid-Based Electrolytes

“…However, limited operating temperature, and a narrow potential window, restrict the diverse application of aqueous and organic electrolyte based EDLCs . ILs are currently emerging as a novel electrolyte material that offers many advantages because of their unusual physicochemical properties and vast application potential in many fields of science and technology. − These unique materials possess a low melting point, high boiling point, negligible vapor pressure, high thermal and chemical stability, and high ionic conductivity. − In addition to the above properties, ILs also possess a wide electrochemical window, higher working temperature, and many more fulfilling current needs of an EDLC for multipurpose applications . ILs being a “green solvent” endows better qualities in IL-based EDLCs.…”

N-octylpyridine hydrogen sulphate ionic liquid for multifunctional fluorescent response in different solvents

“…Ionic liquids (ILs) are molten salts that are liquid at room temperature [ 1 , 2 ] and exhibit unique properties, such as low vapour pressure [ 3 ], high thermal stability [ 4 , 5 ] and good electrical conductivity [ [6] , [7] , [8] ], which offer broad application prospects [ [9] , [10] , [11] ]. Compared with the traditional volatile organic solvents, they have a negligible vapour pressure, making them ‘green’ solvents.…”