Deep Eutectic Solvents as Electrolytes for Zn Batteries: Between Blocked Crystallization, Electrochemical Performance and Corrosion Issues.

Deep eutectic solvents (DESs) are an emerging class of ionic liquids with high tunability and promise for battery applications. In this study, we investigated acetamide-based DESs for Zn batteries, focusing on a synergistic mixture of two known acetamide (Ace)-based DESs: Ace4ZnCl2 and Ace4ZnTFSI2. By combining these two DESs in various ratios, we aimed to enhance ionic conductivity and optimize electrochemical performance while addressing corrosion concerns.

Electrolytes for Zn Batteries: Deep Eutectic Solvents in Polymer Gels.

Gel polymer electrolytes composed of deep eutectic solvent acetamide :Zn(TFSI) and poly(ethylene oxide) (PEO) are prepared by using a fast, solvent-free procedure. The effect of the PEO molecular weight and its concentration on the physicochemical and electrochemical properties of the electrolytes are studied. Gels prepared with ultrahigh molecular-weight PEO present pseudo-solid behavior and ionic conductivity even higher than that of the original liquid electrolyte.

Ionic Conductivity Enhancement in UHMW PEO Gel Electrolytes Based on Room-Temperature Ionic Liquids and Deep Eutectic Solvents.

Physical gels made of poly(ethylene oxide) (PEO) and deep eutectic solvents urea-Li bis(trifluoromethanesulfonyl)imide (TFSI) and ethylene glycol/LiTFSI, or pyrrolidinium ionic liquid solutions PYR13TFSI-LiTFSI and PYR14TFSI-LiTFSI, are prepared by a fast, single-step process, which involves no auxiliary solvents or intermediates and is reproducible and scalable. The properties of these gels are studied as a function of the PEO content and its molecular weight and the nature of the liquid electrolyte. The gels prepared with a low concentration (1-5 wt %) of ultrahigh molecular weight (UHMW) PEO are tough, stretchable materials which resemble soft elastomers and are also self-healing and transparent.

Addressing Manufacturability and Processability in Polymer Gel Electrolytes for Li/Na Batteries.

Gel electrolytes are prepared with Ultra High Molecular Weight (UHMW) polyethylene oxide (PEO) in a concentration ranging from 5 to 30 wt.% and Li- and Na-doped 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (PYR14-TFSI) by a simple procedure consisting of dissolving PEO by melting it directly in the liquid electrolyte while stirring the blend. This procedure is fast, reproducible and needs no auxiliary solvents, which makes it sustainable and potentially easy to scale up for mass production.

Tough Polymer Gel Electrolytes for Aluminum Secondary Batteries Based on Urea: AlCl, Prepared by a New Solvent-Free and Scalable Procedure.

Polymer gel electrolytes have been prepared with polyethylene oxide (PEO) and the deep eutectic mixture of AlCl: urea (uralumina), a liquid electrolyte which has proved to be an excellent medium for the electrodeposition of aluminum. The polymer gel electrolytes are prepared by mixing PEO in the liquid electrolyte at T > 65 °C, which is the melting point of PEO. This procedure takes a few minutes and requires no subsequent evaporation steps, being a solvent-free, and hence more sustainable procedure as compared to solvent-mediated ones.

Solvent-Free and Scalable Procedure to Prepare PYR13TFSI/LiTFSI/PVDF⁻HFP Thermoplastic Electrolytes with Controlled Phase Separation and Enhanced Li Ion Diffusion.

Solid electrolytes for Li transport have been prepared by melt-compounding in one single step. Electrolytes are composed of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) with PYR13TFSI on its own or with varying concentration of LiTFSI. While the extrusion of PVDF-HFP with PYR13TFSI is possible up to relatively high liquid fractions, the compatibility of PVDF-HFP with LiTFSI/PYR13TFSI solutions is much lower.

Solvent-Free Procedure for the Preparation under Controlled Atmosphere Conditions of Phase-Segregated Thermoplastic Polymer Electrolytes.

A solvent-free method that allows thermoplastic solid electrolytes based on poly(ethylene oxide) PEO to be obtained under controlled atmosphere conditions is presented. This method comprises two steps, the first one being the melt compounding of PEO with a filler, able to physically crosslink the polymer and its pelletizing, and the second the pellets' swelling with an electroactive liquid phase. This method is an adaptation of the step described in previous publications of the preparation of thermoplastic electrolytes by a single melt compounding.

Ionic Liquid-Based Thermoplastic Solid Electrolytes Processed by Solvent-Free Procedures.

A series of thermoplastic polymer electrolytes have been prepared employing poly(ethylene oxide) (PEO) as a polymer matrix, bis(trifluoromethane sulfonimide) (LiTFSI), and different room-temperature ionic liquids (RTIL) with bis(fluorosulfonyl)imide (FSI) or TFSI anions. This formulation makes them safe and non-flammable. The electrolytes have been processed in the absence of solvents by melt compounding at 120 °C, using sepiolite modified with d-α-tocoferol-polyethyleneglycol 1000 succinate (TPGS-S) as a physical cross-linker of PEO.