Insights into Ionic Liquids: From Z-Bonds to Quasi-Liquids

Abstract

Ionic liquids (ILs) hold great promise in the fields of green chemistry, environmental science, and sustainable technology due to their unique properties, such as a tailorable structure, the various types available, and their environmentally friendly features. On the basis of multiscale simulations and experimental characterizations, two unique features of ILs are as follows: (1) strong coupling interactions between the electrostatic forces and hydrogen bonds, namely in the Z-bond, and (2) the unique semiordered structure and properties of ultrathin films, specifically regarding the quasi-liquid. In accordance with the aforementioned theoretical findings, many cutting-edge applications have been proposed: for example, CO 2 capture and conversion, biomass conversion and utilization, and energy storage materials. Although substantial progress has been made recently in the field of ILs, considerable challenges remain in understanding the nature of and devising applications for ILs, especially in terms of e.g. in situ /real-time observation and highly precise multiscale simulations of the Z-bond and quasi-liquid. In this Perspective, we review recent developments and challenges for the IL research community and provide insights into the nature and function of ILs, which will facilitate future applications.

Different shapes based on ionic liquid leading to a two-stage discharge process

“…(c) From the perspective of practical application, 55 the suggestion of IL electrolytes in supercapacitors is given, according to the needs of shallow discharge and deep discharge of supercapacitors.…”

Machine Learning Screening of Efficient Ionic Liquids for Targeted Cleavage of the β–O–4 Bond of Lignin

“…To explore the decomposition of lignin, model compounds such as guaiacylglycerol-β-guaiacyl ether (GG), , veratrylglycerol-β-guaiacyl ether (VG), and p -coumaric acid ester (pCA) − are usually used to simplify experiments and theoretical calculations. Ionic liquids (ILs) − act as a kind of green media, consisting of organic cations and inorganic/organic anions. Taking advantage of structural diversity and strong solubility, ILs have been widely used for lignin dissolution and degradation. − Guaiacol is the main product of the β–O–4 bond cleavage, and its yield is often used to quantify the cleavage performance of ILs.…”

Insight into the Camel‐to‐Bell Transition of Differential Capacitance in Ionic Liquid‐Based Supercapacitors

“…Room‐temperature ionic liquids (RTILs) stand for a class of organic salts in the liquid states that are composed solely of ions, which have experienced a sustaining boom in the fields of green chemistry, [1—4] catalysis, [5—8] and electronics [9—11] . Particularly, RTILs, as a new type of non‐aqueous electrolyte, have been utilized in electrical double‐layer capacitors (EDLCs, also called supercapacitors) due to their easily tunable characters, low vapor pressure, and high electrochemical window [12—16] .…”

“…Room-temperature ionic liquids (RTILs) stand for a class of organic salts in the liquid states that are composed solely of ions, which have experienced a sustaining boom in the fields of green chemistry, [1][2][3][4] catalysis, [5][6][7][8] and electronics. [9][10][11] Particularly, RTILs, as a new type of non-aqueous electrolyte, have been utilized in electrical double-layer capacitors (EDLCs, also called supercapacitors) due to their easily tunable characters, low vapor pressure, and high electrochemical window. [12][13][14][15][16] It is well known that the capacitance curve (i. e., capacitance versus electrical potential or surface charge density) is supposed to present a variety of shapes, which largely depends on the structure of the electric double layer (EDL) near the electrode.…”