Synthesis of Vinylidene Fluoride-Based Copolymers Bearing Perfluorinated Ether Pendant Groups and Their Application in Gel Polymer Electrolytes

Abstract

Vinylidene fluoride (VDF)-based copolymers bearing pendant perfluoroalkyl ether groups for potential application in gel polymer electrolytes were synthesized via conventional radical copolymerization of VDF with a 2trifluoromethacrylate monomer bearing pendant perfluoroalkyl ether groups [2,3,3,3-tetrafluoro-2-[1,1,2,3,3,3-hexafluoro-2-(perfluoropropoxy)propoxy]propyl 2-(trifluoromethyl)acrylate (MAF-PFE)]. Two kinds of initiators (hydrogenated and a perfluorinated highly branched persistent radical that released CF 3• radical from 80 °C) were used. Molar masses ranged between 35 000 and ca. 50 000 g•mol −1 . The synthesized poly(VDF-co-MAF-PFE) copolymers were evaluated in gel polymer electrolytes based on ionic liquids. With this aim, the poly(VDF-co-MAF-PFE) copolymers were mixed with lithium bis(trifluoromethanesulfonyl)imide and the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide. Homogeneous gels with conductivity values at room temperature reaching up to 3 × 10 −3 S•cm −1 were obtained, while the transference number of lithium ions was 0.12 at 40 °C. Finally, such electrolytes displayed an electrochemical stability window between 1.5 and 4.4 V as determined by cyclic voltamperometry measurements.

Oxygen Self-Supplying Nanotherapeutic for Mitigation of Tissue Hypoxia and Enhanced Photodynamic Therapy of Bacterial Keratitis

“…Perfluoropolyether methacrylate (FA) was prepared according to a previous report with a little modification. 17 In a typical protocol, perfluoropolyether (480 mg, 1 mmol), triethylamine (100 μL), and freshly dried CH 2 Cl 2 (5 mL) were added into a 10 mL three-necked roundbottom flask under a N 2 atmosphere. Subsequently, methacryloyl chloride (10 mg, 0.1 mmol) was added dropwise at 0 °C.…”

Novel single-ion conducting electrolytes based on vinylidene fluoride copolymer for lithium metal batteries

“…Nevertheless, they can be plasticized using polar solvents such as carbonates, and therefore are largely studied as gel electrolytes [21]. The polymer membranes based on VDF [16,[22][23][24][25], copolymers [26][27][28][29][30][31] or blends with other polymers [32][33][34][35][36][37][38], gelled with a liquid electrolyte made from carbonate solvents and lithium salt, exhibit a high conductivity of up to 10 -3 S cm -1 at 30 °C and a good electrochemical stability of up to 4.5 V vs. Li + /Li [38,39]. However, the conductivity of these gels is mainly driven by the carbonate solvation of both cation and anion, which leads to lithium transference number ( ) lower than 0.45 [40].…”

Highly Elastic and Polar Block Polymer Binder Enabling Accommodation of Volume Change and Confinement of Polysulfide for High-Performance Lithium–Sulfur Batteries

“…Additionally, the cathode with the FBCP binder performed the lowest potential gap (Δ U ) of 0.36 V among binders (0.83 V for BCP and 0.85 V for PVDF). In the opposite of serious polarization between the first activation cycle and the second cycle of the PVDF cathode, almost coincident curves can be observed for the redox peaks between the initial five cycles for FBCP, implying that the cathode with the FBCP binder exhibited better redox-conversion reversibility and faster redox kinetics owing to the excellent stability of FBCP and abundant groups with F atoms and O atoms, which facilitated ionic conductivity and adsorption for LiPSs …”