Confining Ionic Liquids in Developing Quasi‐Solid‐State Electrolytes for Lithium Metal Batteries

Abstract

The concept of confining ionic liquids (ILs) in developing quasi‐solid‐state electrolytes (QSSEs) has been proposed, where ILs are dispersed in polymer networks/backbones and/or filler/host pores, forming the so‐called confinement, and great research progress and promising research results have been achieved. In this review, the progress and achievement in developing QSSEs using IL‐confinement for lithium metal batteries (LMBs), together with advanced characterizations and simulations, were surveyed, summarized, and analyzed, where the influence of specific parameters, such as IL (type, content, etc.), substrate (type, structure, surface properties, etc.), confinement methods, and so on, was discussed. The confinement concept was further compared with the conventional one in other research areas. It indicates that the IL‐confinement in QSSEs improves the performance of electrolytes, for example, increasing the ionic conductivity, widening the electrochemical window, and enhancing the cycle performance of the assembled cells, and being different from those in other areas, i.e., the IL‐confinement concept in the battery area is in a broad extent. Finally, insights into developing QSSEs in LMBs with the confinement strategy were provided to promote the development and application of QSSE LMBs.

Cationic Porous Aromatic Frameworks for Enhanced Lithium-Ion Dissociation and Transport in Solid Polymer Electrolytes

“…QSPE combines the advantages of liquid electrolytes and solid electrolytes, possessing not only high ionic conductivity but also good mechanical strength and interface compatibility, which are conducive to promoting the transport of Li + and ensuring the safety performance of the battery. 11,12 In order to accurately construct anion acceptors in the SPE and achieve rapid transport of Li + , the ideal material should possess abundant reaction sites and exhibit the capability for directed, stable, and rapid transport of Li + . Owing to their designable frameworks and abundant ion transport channels, porous polymers have emerged as promising candidate materials for SPEs that meet these conditions.…”

“…These conditions enable SPEs to achieve high ionic conductivity and a high Li + transference number ( t Li + ). , In addition, a small amount of liquid electrolyte or plasticizer was added to the SPE to enhance the interfacial interaction, resulting in a quasisolid polymer electrolyte (QSPE). QSPE combines the advantages of liquid electrolytes and solid electrolytes, possessing not only high ionic conductivity but also good mechanical strength and interface compatibility, which are conducive to promoting the transport of Li + and ensuring the safety performance of the battery. , …”