Promoting Cathodic Kinetics and Anodic Stability in Practical Room-Temperature Sodium-Sulfur Batteries with Bifunctional Electrolytes.

The development of room-temperature (RT) sodium-sulfur (Na-S) batteries is severely hindered due to the slow kinetics of the S cathode and the instability of the Na-metal anode. To overcome this, we introduced a dual-functional electrolyte cosolvent, trifluoromethanesulfonamide (TFMSA). Short-chain NaS (1 ≤ ≤ 2) can be effectively dissolved due to the strong H-S bond interaction between TFMSA and sulfides, which changes the S conversion process, thereby effectively enhancing the conversion kinetics of the cathode.

Excellent Polymerized Ionic-Liquid-Based Gel Polymer Electrolytes Enabled by Molecular Structure Design and Anion-Derived Interfacial Layer.

Polymerized ionic liquid (PIL)-based gel polymer electrolytes (GPEs) are well known as highly safe and stable electrolytes but with low ambient ionic conductivity. Herein, we first designed and synthesized an IL monomer with a long and flexible side chain and then mixed it with LiTFSI and MEMPTFSI to construct a PIL-based GPE (denoted as GM-GPE). The special molecular structure of the monomer greatly improves the ionic transport through the PIL chain, and the introduction of MEMPTFSI plasticizer further improves the ionic conductivity, promoting a TFSI-anion-derived SEI formation to suppress Li dendrite growth and forming an electrostatic shielding effect of MEMP cations to promote the uniform deposition of Li.

Highly Conductive Polymeric Ionic Liquid Electrolytes for Ambient-Temperature Solid-State Lithium Batteries.

High-energy density solid-state lithium metal batteries are expected to become the next generation of energy storage devices. Polymeric ionic liquid-based solid polymer electrolytes (PIL-based SPEs) are an attractive choice among electrolytes, but their ionic conductivities are generally insufficient due to numerous crystallized polymer regions. To achieve higher conductivity, we use facile copolymerization of an ionic liquid (IL) monomer and poly(ethylene glycol) diacrylate monomer to obtain in situ plasticized polymer chains.