Ionic liquids and derived materials for lithium and sodium batteries

Abstract

The ever-growing demand for advanced energy storage devices in portable electronics, electric vehicles and large scale power grids has triggered intensive research efforts over the past decade on lithium and sodium batteries. The key to improve their electrochemical performance and enhance the service safety lies in the development of advanced electrode, electrolyte, and auxiliary materials. Ionic liquids (ILs) are liquids consisting entirely of ions near room temperature, and are characterized by many unique properties such as ultralow volatility, high ionic conductivity, good thermal stability, low flammability, a wide electrochemical window, and tunable polarity and basicity/acidity. These properties create the possibilities of designing batteries with excellent safety, high energy/power density and long-term stability, and also provide better ways to synthesize known materials. IL-derived materials, such as poly(ionic liquids), ionogels and IL-tethered nanoparticles, retain most of the characteristics of ILs while being endowed with other favourable features, and thus they have received a great deal of attention as well. This review provides a comprehensive review of the various applications of ILs and derived materials in lithium and sodium batteries including Li/Na-ion, dual-ion, Li/Na-S and Li/Na-air (O) batteries, with a particular emphasis on recent advances in the literature. Their unique characteristics enable them to serve as advanced resources, medium, or ingredient for almost all the components of batteries, including electrodes, liquid electrolytes, solid electrolytes, artificial solid-electrolyte interphases, and current collectors. Some thoughts on the emerging challenges and opportunities are also presented in this review for further development.

Ionic Liquids as Solvents for SN2 Processes. Demonstration of the Complex Interplay of Interactions Resulting in the Observed Solvent Effects

“…[2,4] There are a plethora of cation and anion combinations possible, resulting in ionic liquids with a wide range of physicochemical properties; [2,4b,5] for this reason, they are often described as 'designer solvents'. [2,4b,6] Given the potential benefits, ionic liquids have been considered for a broad variety of applications; these range from biomass pretreatment [7] through energy storage [8] and batteries [9] to biomedical applications [10] and separation technologies. [11] In all of these cases, along with analyses of potential impacts of these salts on the environment, [12] a key feature is the ability to choose an ionic liquid with the properties appropriate for the application.…”

Gradient‐Distributed Nucleation Seeds on Conductive Host for a Dendrite‐Free and High‐Rate Lithium Metal Anode

“…Lithium metal anode (LMA) has been deemed as a prime anode in future secondary cells with energy density over 500 Wh kg −1 , due to its outstanding intrinsic electrochemical characteristics of high theoretical specific capacity and lowest electric potential . The superactive properties of metal lithium bring about the inevitable existence of solid electrolyte interface (SEI) on lithium surface.…”

Ionic Liquids and their Polymers in Lithium‐Sulfur Batteries

“…Moreover, ILs can be used as starting materials to produce poly(ionic liquids) (PILs), combining the beneficial properties of “normal” ILs with properties of polymers, such as mechanical stability and processability. This marriage of properties has initiated new research frontiers with broad applicability, for example the use of PILs as particles, membranes, and coatings . ILs and IL‐derived materials have been investigated for a variety of functions in batteries, including fabrication of electrode materials, as electrolytes, as binders, as artificial solid electrolyte interphase (a‐SEI) layer to protect the Li‐metal anode, as coating to enhance the interfacial wettability and stability in solid electrolyte cells, and as medium or solvent in the preparation of battery components .…”